PilotHandbook

Pilots can perceive hazards by using the CARE checklist: Aircraft
• Consequences: This area presents low risk because the
Pilot
• Consequences: Gayle’s inexperience and lack of recent aircraft is in excellent mechanical condition and Gayle is
familiar with its avionics.
flight time create some risk of an accident, primarily because • Alternatives: Had there been a problem with her aircraft,
she plans to travel over mountains on a hazy day and land Gayle might have considered renting another plane from her
at an unfamiliar mountain airport that is still in IMC flight school. Bear in mind, however, that alternatives
conditions. sometimes create new hazards. In this instance, there may
• Alternatives: Gayle might mitigate the pilot-related risk by be hazards associated with flying an unfamiliar aircraft with
hiring a CFI to accompany her and provide dual cross- different avionics.
country instruction. An added benefit is the opportunity to • Reality: It is important to recognize the reality of an aircraft’s
broaden her flying experience in safe conditions. mechanical condition. If you find a maintenance discrepancy
• Reality: Accepting the reality that limited experience can and then find yourself saying that it is “probably” okay to fly
create additional risk is a key part of sound risk management with it anyway, you need to revisit the consequences part of
and mitigation. this checklist.
• External Factors: Like many pilots, Gayle must contend with • External Factors: Pilot decision-making can sometimes be
the emotional pressure associated with acknowledging that influenced by the external pressure of needing to return the
her skill and experience levels may be lower than she would airplane to the FBO by a certain date and time. Because
like them to be. Pride can be a powerful external factor! Gayle owns the airplane, there was no such pressure in this
case.
Environment
• Consequences: For a pilot whose experience consists External Pressures
• Consequences: Any number of factors can create risk of
mostly of local flights in good VMC, launching a long cross-
country flight over mountainous terrain in hazy conditions emotional pressure from a “get-there” mentality. In Gayle’s
could lead to pilot disorientation and increase the risk of an case, the consequences of her strong desire to visit family,
accident. her family’s expectations, and personal pride could induce
• Alternatives: Options include postponing the trip until the her to accept unnecessary risk.
visibility improves, or modifying the route to avoid extended • Alternatives: Gayle clearly needs to develop a mitigating
periods of time over the mountains. strategy for each of the external factors associated with this
• Reality: Hazy conditions and mountainous terrain clearly trip.
create risk for an inexperienced VFR-only pilot. • Reality: Pilots sometimes tend to discount or ignore the
• External Factors: Few pilots are immune to the pressure of potential impact of these external factors. Gayle’s open
“get-there-itis,” which can sometimes induce a decision to acknowledgement of these factors (e.g., “I might be
launch or continue in less than ideal weather conditions. pressured into pressing on so my mother won’t have to
worry about our late arrival.”) is a critical element of effective
risk management.
• External Factors: (see above)

Figure 17-9. Additional real-world examples of how the 3P model guides decisions on a cross-country trip.

Forming Good Safety Habits Loop is now used as a standard description of decision-
making cycles.
While the 3P model is similar to other methods, there are
two good reasons to use the 3P model. First, the 3P model The Loop is an interlaced decision model which provides
gives pilots a structured, efficient, and systematic way to immediate feedback throughout the decision-making process.
identify hazards, assess risk, and implement effective risk For SRM purposes, an abbreviated version of the concept
controls. Second, practicing risk management needs to be as [Figure 17-10] provides an easily understood tool for the
automatic in GA flying as basic aircraft control. As is true pilot.
for other flying skills, risk management thinking habits are
best developed through repetition and consistent adherence The first node of the Loop, Observe, reflects the need for
to specific procedures. situational awareness. A pilot must be aware of those things
around him or her that may impact the flight. Continuous
The OODA Loop monitoring of aircraft controls, weather, etc., provides a
Colonel John Boyd, United States Air Forces (Retired), constant reference point by which the pilot knows his or
coined the term and developed the concept of the “OODA her starting point on the loop which permits the ability to
Loop” (Observation, Orientation, Decision, Action). The immediately move to the next step.
ideas, words, and phrases contained in Boyd’s briefings have
penetrated not only the United States military services, but the
business community and worldwide academia. The OODA

17-16

First, consider a recent accident involving a Piper Apache (PA-

OBSERVE 23). The aircraft was substantially damaged during impact
with terrain at a local airport in Alabama. The certificated

airline transport pilot (ATP) received minor injuries and the

certificated private pilot was not injured. The private pilot

was receiving a checkride from the ATP (who was also a

designated examiner) for a commercial pilot certificate with

a multi-engine rating. After performing airwork at altitude,

ACT ORIENT they returned to the airport and the private pilot performed a

single-engine approach to a full stop landing. He then taxied

back for takeoff, performed a short field takeoff, and then

joined the traffic pattern to return for another landing. During

the approach for the second landing, the ATP simulated a right

engine failure by reducing power on the right engine to zero

DECIDE thrust. This caused the aircraft to yaw right.

The procedure to identify the failed engine is a two-step

process. First, bring power to maximum controllable on both

engines. Because the left engine is the only engine delivering

Figure 17-10. The OODA Loop. thrust, the yaw increases to the right, which necessitates

application of additional left rudder application. The failed
OFigriuernet,1t-h8e. TsheecOobnsdernvoatdioeno, Of rtiehnetaLtiooonp, D, efcoisciuosne, Asctthioen p(OilOoDt’As Looepn)g. ine is the side that requires no rudder pressure, in this
attention on one or more discrepancies in the flight. For case the right engine. Second, having identified the failed
example, there is a low oil pressure reading. The pilot is right engine, the procedure is to feather the right engine and
aware of this deviation and considers available options in adjust power to maintain descent angle to a landing.
view of potential hazards to continued flight.

The pilot then moves to the third node, Decide, in which However, in this case the pilot feathered the left engine
he or she makes a positive determination about a specific because he assumed the engine failure was a left engine
effect. That decision is made based on experience and failure. During twin-engine training, the left engine out
knowledge of potential results, and to take that particular is emphasized more than the right engine because the left
action will produce the desired result. The pilot then Acts on engine on most light twins is the critical engine. This is due to
that decision, making a physical input to cause the aircraft multiengine airplanes being subject to P-factor, as are single-
to react in the desired fashion. engine airplanes. The descending propeller blade of each
engine will produce greater thrust than the ascending blade

Once the loop has been completed, the pilot is once again in when the airplane is operated under power and at positive
the Observe position. The assessment of the resulting action angles of attack. The descending propeller blade of the right
is added to the previously perceived aspects of the flight to engine is also a greater distance from the center of gravity,
further define the flight’s progress. The advantage of the and therefore has a longer moment arm than the descending
OODA Loop model is that it may be cumulative, as well as propeller blade of the left engine. As a result, failure of the left
having the potential of allowing for multiple progressions to engine will result in the most asymmetrical thrust (adverse
occur at any given point in the flight. yaw) because the right engine will be providing the remaining
thrust. Many twins are designed with a counter-rotating right

The DECIDE Model engine. With this design, the degree of asymmetrical thrust
Using the acronym “DECIDE,” the six-step process DECIDE is the same with either engine inoperative. Neither engine is
Model is another continuous loop process that provides the more critical than the other.

pilot with a logical way of making decisions. [Figure 17-11]

DECIDE means to Detect, Estimate, Choose a course of

action, Identify solutions, Do the necessary actions, and

Evaluate the effects of the actions.

17-17

A. Analytical Aeronautical Decision-Making
B. Automatic/Naturalistic

Situation Pilot Aircraft Enviroment External Factors

Pilot Aircraft Enviroment External Factors

Detection Detection

Evaluation of event Evaluation of event

• Risk or hazard • Risk to flight
• Potential outcomes • Pilot training
• Capabilities of pilot • Pilot experience
• Aircraft capabilities
• Outside factors Outcome desired

Outcome desired Take action

Solutions to get you there
Solution 1
Solution 2
Solution 3
Solution 4

What is best action to do

Effect of decision Successful
Problem remains

Done

The DECIDE Model

1.
2.
3.
4
5.
6.

Figure 17-11. The DECIDE model has been recognized worldwide. Its application is illustrated in A while automatic/naturalistic
decision-making is shown in B.

17-18

Since the pilot never executed the first step of identifying the environment. Experience, discipline, awareness, and
which engine failed, he feathered the left engine and set the knowledge will influence how a pilot ranks a problem.
right engine at zero thrust. This essentially restricted the
aircraft to a controlled glide. Upon realizing that he was not Choose (a Course of Action)
going to make the runway, the pilot increased power to both After the problem has been identified and its impact
engines causing an enormous yaw to the left (the left propeller estimated, the pilot must determine the desirable outcome
was feathered) whereupon the aircraft started to turn left. and choose a course of action. In the case of the multiengine
In desperation, the instructor closed both throttles and the pilot given the simulated failed engine, the desired objective
aircraft hit the ground and was substantially damaged. is to safely land the airplane.

This case is interesting because it highlights two particular Identify (Solutions)
issues. First, taking action without forethought can be just The pilot formulates a plan that will take him or her to the
as dangerous as taking no action at all. In this case, the objective. Sometimes, there may be only one course of action
pilot’s actions were incorrect; yet, there was sufficient available. In the case of the engine failure, already at 500
time to take the necessary steps to analyze the simulated feet or below, the pilot solves the problem by identifying
emergency. The second and more subtle issue is that decisions one or more solutions that lead to a successful outcome. It is
made under pressure are sometimes executed based upon important for the pilot not to become fixated on the process
limited experience and the actions taken may be incorrect, to the exclusion of making a decision.
incomplete, or insufficient to handle the situation.
Do (the Necessary Actions)
Detect (the Problem) Once pathways to resolution are identified, the pilot selects
Problem detection is the first step in the decision-making the most suitable one for the situation. The multiengine pilot
process. It begins with recognizing a change occurred or an given the simulated failed engine must now safely land the
expected change did not occur. A problem is perceived first aircraft.
by the senses and then it is distinguished through insight
and experience. These same abilities, as well as an objective Evaluate (the Effect of the Action)
analysis of all available information, are used to determine the Finally, after implementing a solution, evaluate the decision
nature and severity of the problem. One critical error made to see if it was correct. If the action taken does not provide
during the decision-making process is incorrectly detecting the desired results, the process may have to be repeated.
the problem. In the example above, the change that occurred
was a yaw. Decision-Making in a Dynamic
Environment
Estimate (the Need To React)
In the engine-out example, the aircraft yawed right, the pilot The common approach to decision-making has been through
was on final approach, and the problem warranted a prompt the use of analytical models such as 5P, 3P, OODA, and
solution. In many cases, overreaction and fixation excludes DECIDE. Good decisions result when pilots gather all
a safe outcome. For example, what if the cabin door of a available information, review it, analyze the options, rate the
Mooney suddenly opened in flight while the aircraft climbed options, select a course of action, and evaluate that course of
through 1,500 feet on a clear sunny day? The sudden opening action for correctness.
would be alarming, but the perceived hazard the open door
presents is quickly and effectively assessed as minor. In In some situations, there isn’t always time to make decisions
fact, the door’s opening would not impact safe flight and based on analytical decision-making skills. A good example
can almost be disregarded. Most likely, a pilot would return is a quarterback whose actions are based upon a highly fluid
to the airport to secure the door after landing. and changing situation. He intends to execute a plan, but new
circumstances dictate decision-making on the fly. This type
The pilot flying on a clear day faced with this minor problem of decision-making is called automatic decision-making or
may rank the open cabin door as a low risk. What about naturalized decision-making. [Figure 17-11B]
the pilot on an IFR climb out in IMC conditions with light
intermittent turbulence in rain who is receiving an amended
clearance from air traffic control (ATC)? The open cabin
door now becomes a higher risk factor. The problem has
not changed, but the perception of risk a pilot assigns it
changes because of the multitude of ongoing tasks and

17-19

Automatic Decision-Making and prevents complacency. Effects of stress are cumulative
In an emergency situation, a pilot might not survive if he or and, if the pilot does not cope with them in an appropriate
she rigorously applied analytical models to every decision way, they can eventually add up to an intolerable burden.
made; there is not enough time to go through all the options. Performance generally increases with the onset of stress,
But under these circumstances does he or she find the best peaks, and then begins to fall off rapidly as stress levels
possible solution to every problem? exceed a person’s ability to cope. The ability to make
effective decisions during flight can be impaired by stress.
For the past several decades, research into how people There are two categories of stress—acute and chronic. These
actually make decisions has revealed that when pressed for are both explained in Chapter 16, Aeromedical Factors.
time, experts faced with a task loaded with uncertainty, first
assess whether the situation strikes them as familiar. Rather Factors referred to as stressors can increase a pilot’s risk of
than comparing the pros and cons of different approaches, error in the flight deck. [Figure 17-13] Remember the cabin
they quickly imagine how one or a few possible courses of door that suddenly opened in flight on the Mooney climbing
action in such situations will play out. Experts take the first through 1,500 feet on a clear sunny day? It may startle the
workable option they can find. While it may not be the best of pilot, but the stress would wane when it became apparent
all possible choices, it often yields remarkably good results. the situation was not a serious hazard. Yet, if the cabin door
opened in IMC conditions, the stress level makes significant
The terms naturalistic and automatic decision-making have impact on the pilot’s ability to cope with simple tasks. The
been coined to describe this type of decision-making. The key to stress management is to stop, think, and analyze before
ability to make automatic decisions holds true for a range jumping to a conclusion. There is usually time to think before
of experts from fire fighters to chess players. It appears the drawing unnecessary conclusions.
expert’s ability hinges on the recognition of patterns and
consistencies that clarify options in complex situations. There are several techniques to help manage the accumulation
Experts appear to make provisional sense of a situation, of life stresses and prevent stress overload. For example, to
without actually reaching a decision, by launching experience- help reduce stress levels, set aside time for relaxation each
based actions that in turn trigger creative revisions. day or maintain a program of physical fitness. To prevent
stress overload, learn to manage time more effectively to
This is a reflexive type of decision-making anchored in avoid pressures imposed by getting behind schedule and not
training and experience and is most often used in times of meeting deadlines.
emergencies when there is no time to practice analytical
decision-making. Naturalistic or automatic decision-making Use of Resources
improves with training and experience, and a pilot will find To make informed decisions during flight operations, a pilot
himself or herself using a combination of decision-making must also become aware of the resources found inside and
tools that correlate with individual experience and training. outside the flight deck. Since useful tools and sources of
information may not always be readily apparent, learning
Operational Pitfalls to recognize these resources is an essential part of ADM
Although more experienced pilots are likely to make more training. Resources must not only be identified, but a pilot
automatic decisions, there are tendencies or operational must also develop the skills to evaluate whether there is
pitfalls that come with the development of pilot experience. time to use a particular resource and the impact its use will
These are classic behavioral traps into which pilots have have upon the safety of flight. For example, the assistance
been known to fall. More experienced pilots (as a rule) try of ATC may be very useful if a pilot becomes lost, but in
to complete a flight as planned, please passengers, and meet an emergency situation, there may be no time available to
schedules. The desire to meet these goals can have an adverse contact ATC.
effect on safety and contribute to an unrealistic assessment
of piloting skills. All experienced pilots have fallen prey to, Internal Resources
or have been tempted by, one or more of these tendencies in One of the most underutilized resources may be the person in
their flying careers. These dangerous tendencies or behavior the right seat, even if the passenger has no flying experience.
patterns, which must be identified and eliminated, include When appropriate, the PIC can ask passengers to assist with
the operational pitfalls shown in Figure 17-12. certain tasks, such as watching for traffic or reading checklist
items. Some other ways a passenger can assist:
Stress Management
Everyone is stressed to some degree almost all of the time. A • Provide information in an irregular situation, especially
certain amount of stress is good since it keeps a person alert if familiar with flying. A strange smell or sound may
alert a passenger to a potential problem.

17-20

Operational Pitfalls

Peer Pressure
Poor decision-making may be based upon an emotional response to peers, rather than evaluating a situation objectively.

Mind Set
A pilot displays mind set through an inability to recognize and cope with changes in a given situation.

Get-there-itis
This disposition impairs pilot judgment through a fixation on the original goal or destination, combined with a disregard for any
alternative course of action.

Duck-Under Syndrome
A pilot may be tempted to make it into an airport by descending below minimums during an approach. There may be a belief that
there is a built-in margin of error in every approach procedure, or a pilot may want to admit that the landing cannot be completed
and a missed approach must be initiated.

Scud Running
This occurs when a pilot tries to maintain visual contact with the terrain at low altitudes while instrument conditions exist.

Continuing Visual Flight Rules (VFR) into Instrument Conditions
Spatial disorientation or collision with ground/obstacles may occur when a pilot continues VFR into instrument conditions. This can
be even more dangerous if the pilot is not instrument rated or current.

Getting Behind the Aircraft
This pitfall can be caused by allowing events or the situation to control pilot actions. A constant state of surprise at what happens
next may be exhibited when the pilot is getting behind the aircraft.

Loss of Positional or Situational Awareness
In extreme cases, when a pilot gets behind the aircraft, a loss of positional or situational awareness may result. The pilot may not
know the aircraft’s geographical location, or may be unable to recognize deteriorating circumstances.

Operating Without Adequate Fuel Reserves
Ignoring minimum fuel reserve requirements is generally the result of overconfidence, lack of flight planning, or disregarding
applicable regulations.

Descent Below the Minimum En Route Altitude
The duck-under syndrome, as mentioned above, can also occur during the en route portion of an IFR flight.

Flying Outside the Envelope
The assumed high performance capability of a particular aircraft may cause a mistaken belief that it can meet the demands
imposed by a pilot’s overestimated flying skills.

Neglect of Flight Planning, Preflight Inspections, and Checklists
A pilot may rely on short- and long-term memory, regular flying skills, and familiar routes instead of established procedures and
published checklists. This can be particularly true of experienced pilots.

Figure 17-12. Typical operational pitfalls requiring pilot awareness.

Stressors

Environmental Figure 17-13. System stressors. Environmental, physiological, and
Conditions associated with the environment, such as psychological stress are factors which affect decision-making skills.
temperature and humidity extremes, noise, vibration, and lack These stressors have a profound impact especially during periods
of oxygen. of high workload.

Physiological Stress
Physical conditions, such as fatigue, lack of physical fitness,
sleep loss, missed meals (leading to low blood sugar levels),
and illness.

Psychological Stress
Social or emotional factors, such as a death in the family, a
divorce, a sick child, or a demotion at work. This type of stress
may also be related to mental workload, such as analyzing a
problem, navigating an aircraft, or making decisions.

17-21

• Confirm after the pilot that the landing gear is It is necessary for a pilot to have a thorough understanding

down. of all the equipment and systems in the aircraft being flown.

• Learn to look at the altimeter for a given altitude in a Lack of knowledge, such as knowing if the oil pressure
descent. gauge is direct reading or uses a sensor, is the difference
between making a wise decision or poor one that leads to a
• Listen to logic or lack of logic.
tragic error.

Also, the process of a verbal briefing (which can happen Checklists are essential flight deck internal resources. They
whether or not passengers are aboard) can help the PIC in are used to verify the aircraft instruments and systems are
the decision-making process. For example, assume a pilot checked, set, and operating properly, as well as ensuring
provides a lone passenger a briefing of the forecast landing the proper procedures are performed if there is a system
weather before departure. When the Automatic Terminal malfunction or inflight emergency. Students reluctant to
Information Service (ATIS) is picked up, the weather has use checklists can be reminded that pilots at all levels of
significantly changed. The discussion of this forecast change experience refer to checklists, and that the more advanced the
can lead the pilot to reexamine his or her activities and aircraft is, the more crucial checklists become. In addition, the
decision-making. [Figure 17-14] Other valuable internal pilot’s operating handbook (POH) is required to be carried on
resources include ingenuity, aviation knowledge, and flying board the aircraft and is essential for accurate flight planning
skill. Pilots can increase flight deck resources by improving and resolving inflight equipment malfunctions. However, the
these characteristics. most valuable resource a pilot has is the ability to manage
workload whether alone or with others.
When flying alone, another internal resource is verbal
communication. It has been established that verbal External Resources
communication reinforces an activity; touching an object
while communicating further enhances the probability an Air traffic controllers and flight service specialists are the best
activity has been accomplished. For this reason, many solo external resources during flight. In order to promote the safe,
pilots read the checklist out loud; when they reach critical orderly flow of air traffic around airports and, along flight
items, they touch the switch or control. For example, to routes, the ATC provides pilots with traffic advisories, radar
ascertain the landing gear is down, the pilot can read the vectors, and assistance in emergency situations. Although
checklist. But, if he or she touches the gear handle during the it is the PIC’s responsibility to make the flight as safe as
process, a safe extension of the landing gear is confirmed. possible, a pilot with a problem can request assistance from
ATC. [Figure 17-15] For example, if a pilot needs to level
off, be given a vector, or decrease speed, ATC assists and

Figure 17-14. When possible, have a passenger reconfirm that critical tasks are completed.
17-22

request practice DF guidance and approaches in VFR weather
conditions.

Situational Awareness

Situational awareness is the accurate perception and
understanding of all the factors and conditions within
the five fundamental risk elements (flight, pilot, aircraft,
environment, and type of operation that comprise any given
aviation situation) that affect safety before, during, and after
the flight. Monitoring radio communications for traffic,
weather discussion, and ATC communication can enhance
situational awareness by helping the pilot develop a mental
picture of what is happening.

Figure 17-15. Controllers work to make flights as safe as Maintaining situational awareness requires an understanding
possible. of the relative significance of all flight related factors and their
future impact on the flight. When a pilot understands what is
becomes integrated as part of the crew. The services provided going on and has an overview of the total operation, he or she
by ATC can not only decrease pilot workload, but also help is not fixated on one perceived significant factor. Not only
pilots make informed inflight decisions. is it important for a pilot to know the aircraft’s geographical
location, it is also important he or she understand what is
The FSS are air traffic facilities that provide pilot briefing, happening. For instance, while flying above Richmond,
en route communications, VFR search and rescue services, Virginia, toward Dulles Airport or Leesburg, the pilot
assist lost aircraft and aircraft in emergency situations, relay should know why he or she is being vectored and be able to
ATC clearances, originate Notices to Airmen (NOTAM), anticipate spatial location. A pilot who is simply making turns
broadcast aviation weather and National Airspace System without understanding why has added an additional burden
(NAS) information, receive and process IFR flight plans, to his or her management in the event of an emergency. To
and monitor navigational aids (NAVAIDs). In addition, at maintain situational awareness, all of the skills involved in
selected locations, FSSs provide En Route Flight Advisory ADM are used.
Service (Flight Watch), issue airport advisories, and advise
Customs and Immigration of transborder flights. Selected Obstacles to Maintaining Situational Awareness
FSSs in Alaska also provide TWEB recordings and take Fatigue, stress, and work overload can cause a pilot to fixate
weather observations. on a single perceived important item and reduce an overall
situational awareness of the flight. A contributing factor
Another external resource available to pilots is the VHF in many accidents is a distraction that diverts the pilot’s
Direction Finder (VHF/DF). This is one of the common attention from monitoring the instruments or scanning outside
systems that helps pilots without their being aware of its the aircraft. Many flight deck distractions begin as a minor
operation. FAA facilities that provide VHF/DF service are problem, such as a gauge that is not reading correctly, but
identified in the A/FD. DF equipment has long been used result in accidents as the pilot diverts attention to the perceived
to locate lost aircraft and to guide aircraft to areas of good problem and neglects to properly control the aircraft.
weather or to airports. DF instrument approaches may be
given to aircraft in a distress or urgency condition. Workload Management

Experience has shown that most emergencies requiring DF Effective workload management ensures essential operations
assistance involve pilots with little flight experience. With this are accomplished by planning, prioritizing, and sequencing
in mind, DF approach procedures provide maximum flight tasks to avoid work overload. [Figure 17-16] As experience
stability in the approach by using small turns, and wings- is gained, a pilot learns to recognize future workload
level descents. The DF specialist will give the pilot headings requirements and can prepare for high workload periods
to fly and tell the pilot when to begin descent. If followed, during times of low workload. Reviewing the appropriate
the headings will lead the aircraft to a predetermined point chart and setting radio frequencies well in advance of when
such as the DF station or an airport. To become familiar with they are needed helps reduce workload as the flight nears the
the procedures and other benefits of DF, pilots are urged to airport. In addition, a pilot should listen to ATIS, Automated
Surface Observing System (ASOS), or Automated Weather

17-23

Recognizing a work overload situation is also an important
component of managing workload. The first effect of
high workload is that the pilot may be working harder but
accomplishing less. As workload increases, attention cannot
be devoted to several tasks at one time, and the pilot may
begin to focus on one item. When a pilot becomes task
saturated, there is no awareness of input from various sources,
so decisions may be made on incomplete information and the
possibility of error increases. [Figure 17-17]

When a work overload situation exists, a pilot needs to stop,
think, slow down, and prioritize. It is important to understand
how to decrease workload. For example, in the case of the
cabin door that opened in VFR flight, the impact on workload
should be insignificant. If the cabin door opens under IFR
different conditions, its impact on workload will change.
Therefore, placing a situation in the proper perspective,
remaining calm, and thinking rationally are key elements in
reducing stress and increasing the capacity to fly safely. This
ability depends upon experience, discipline, and training.

Figure 17-16. Balancing workloads can be a difficult task. Managing Risks

Observing System (AWOS), if available, and then monitor The ability to manage risk begins with preparation. Here are
the tower frequency or Common Traffic Advisory Frequency some things a pilot can do to manage overall risk:
(CTAF) to get a good idea of what traffic conditions to
expect. Checklists should be performed well in advance so • Assess the flight’s risk based upon experience.
there is time to focus on traffic and ATC instructions. These Use some form of risk assessment. For example, if
procedures are especially important prior to entering a high- the weather is marginal and the pilot has low IMC
density traffic area, such as Class B airspace. training, it is probably a good idea to cancel the
flight.

High

LowTask Load PilotCapabilities

Preflight TaskRequirements
Takeoff Time

Cruise

Approach & Landing

Figure 17-17. The pilot has a certain capacity of doing work and handling tasks. However, there is a point where the tasking exceeds the
pilot’s capability. When this happens, tasks are either not done properly or some are not done at all.

17-24

• Brief passengers using the SAFETY list: Automation is the single most important advance in aviation
technologies. Electronic flight displays (EFDs) have made
S Seat belts fastened for taxi, takeoff, landing vast improvements in how information is displayed and
what information is available to the pilot. Pilots can access
Shoulder harness fastened for takeoff, landing electronic databases that contain all of the information
traditionally contained in multiple handbooks, reducing
Seat position adjusted and locked in place clutter in the flight deck. [Figure 17-18]

A Air vents (location and operation) Multifunction displays (MFDs) are capable of displaying
moving maps that mirror sectional charts. These detailed
All environmental controls (discussed) displays depict all airspace, including Temporary Flight
Restrictions (TFRs). MFDs are so descriptive that many
Action in case of any passenger discomfort pilots fall into the trap of relying solely on the moving
maps for navigation. Pilots also draw upon the database to
F Fire extinguisher (location and operation) familiarize themselves with departure and destination airport
information.
E Exit doors (how to secure; how to open)
More pilots now rely on electronic databases for flight
Emergency evacuation plan planning and use automated flight planning tools rather than
planning the flight by the traditional methods of laying out
Emergency/survival kit (location and contents) charts, drawing the course, identifying navigation points
(assuming a VFR flight), and using the POH to figure out
T Traffic (scanning, spotting, notifying pilot) the weight and balance and performance charts. Whichever
method a pilot chooses to plan a flight, it is important to
Talking, (“sterile flight deck” expectations) remember to check and confirm calculations

Y Your questions? (Speak up!) Although automation has made flying safer, automated
systems can make some errors more evident, and sometimes
• In addition to the SAFETY list, discuss with hide other errors or make them less evident. There are concerns
passengers whether or not smoking is permitted, flight about the effect of automation on pilots. In a study published
route altitudes, time en route, destination, weather in 1995, the British Airline Pilots Association officially
during flight, expected weather at the destination, voiced its concern that “Airline pilots increasingly lack ‘basic
controls and what they do, and the general capabilities flying skills’ as a result of reliance on automation.”
and limitations of the aircraft.
This reliance on automation translates into a lack of basic
• Use a sterile flight deck (one that is completely silent flying skills that may affect the pilot’s ability to cope with
with no pilot communication with passengers or by an inflight emergency, such as sudden mechanical failure.
passengers) from the time of departure to the first The worry that pilots are becoming too reliant on automated
intermediate altitude and clearance from the local systems and are not being encouraged or trained to fly
airspace. manually has grown with the increase in the number of MFD
flight decks.
• Use a sterile flight deck during arrival from the
first radar vector for approach or descent for the As automated flight decks began entering everyday line
approach. operations, instructors and check airmen grew concerned
about some of the unanticipated side effects. Despite the
• Keep the passengers informed during times when the promise of reducing human mistakes, the flight managers
workload is low. reported the automation actually created much larger errors
at times. In the terminal environment, the workload in an
• Consider using the passenger in the right seat for automated flight deck actually seemed higher than in the older
simple tasks such as holding the chart. This relieves analog flight decks. At other times, the automation seemed
the pilot of a task. to lull the flight crews into complacency. Over time, concern
surfaced that the manual flying skills of the automated flight
Automation

In the GA community, an automated aircraft is generally
comprised of an integrated advanced avionics system
consisting of a primary flight display (PFD), a multifunction
flight display (MFD) including an instrument-certified Global
Positioning System (GPS) with traffic and terrain graphics,
and a fully integrated autopilot. This type of aircraft is
commonly known as an advanced avionics aircraft. In an
advanced avionics aircraft, there are typically two display
(computer) screens, PFD (left display screen) and the
MFD.

17-25

Figure 17-18. Electronic flight instrumentation comes in many systems and provides a myriad of information to the pilot.
Figure 16-10. Electronic Flight instrumentation come in many systems and provides a myriad of information to the pilot.

17-26

crews deteriorated due to over-reliance on computers. The While a pilot’s lack of familiarity with the EFIS is often
flight crew managers said they worried that pilots would have an issue, the approach would have been made easier by
less “stick-and-rudder” proficiency when those skills were disengaging the automated system and manually flying the
needed to manually resume direct control of the aircraft. approach. At the time of this study, the general guidelines
in the industry were to let the automated system do as much
A major study was conducted to evaluate the performance of the flying as possible. That view has since changed and
of two groups of pilots. The control group was composed it is recommended that pilots use their best judgment when
of pilots who flew an older version of a common twin- choosing which level of automation will most efficiently
jet airliner equipped with analog instrumentation and the do the task considering the workload and situational
experimental group was composed of pilots who flew the awareness.
same aircraft, but newer models equipped with an electronic
flight instrument system (EFIS) and a flight management Emergency maneuvers clearly broadened the difference in
system (FMS). The pilots were evaluated in maintaining manual flying skills between the two groups. In general, the
aircraft parameters such as heading, altitude, airspeed, analog pilots tended to fly raw data, so when they were given
glideslope, and localizer deviations, as well as pilot control an emergency such as an engine failure and were instructed
inputs. These were recorded during a variety of normal, to fly the maneuver without a flight director, they performed
abnormal, and emergency maneuvers during 4 hours of it expertly. By contrast, SOP for EFIS operations at the time
simulator sessions. was to use the flight director. When EFIS crews had their
flight directors disabled, their eye scan again began a more
Results of the Study erratic searching pattern and their manual flying subsequently
When pilots who had flown EFIS for several years were suffered.
required to fly various maneuvers manually, the aircraft
parameters and flight control inputs clearly showed some Those who reviewed the data saw that the EFIS pilots who
erosion of flying skills. During normal maneuvers such as better managed the automation also had better flying skills.
turns to headings without a flight director, the EFIS group While the data did not reveal whether those skills preceded
exhibited somewhat greater deviations than the analog group. or followed automation, it did indicate that automation
Most of the time, the deviations were within the practical test management needed to be improved. Recommended “best
standards (PTS), but the pilots definitely did not keep on the practices” and procedures have remedied some of the earlier
localizer and glideslope as smoothly as the analog group. problems with automation.

The differences in hand-flying skills between the two groups Pilots need to maintain their flight skills and ability to
became more significant during abnormal maneuvers such maneuver aircraft manually within the standards set forth in
as slam-dunks. When given close crossing restrictions, the the PTS. It is recommended that pilots of automated aircraft
analog crews were more adept at the mental math and usually occasionally disengage the automation and manually fly
maneuvered the aircraft in a smoother manner to make the the aircraft to maintain stick-and-rudder proficiency. It
restriction. On the other hand, the EFIS crews tended to go is imperative pilots understand that the EFD adds to the
“heads down” and tried to solve the crossing restriction on overall quality of the flight experience, but it can also lead to
the FMS. [Figure 17-19] catastrophe if not utilized properly. At no time is the moving
map meant to substitute for a VFR sectional or low altitude
Another situation used in the simulator experiment reflected en route chart.
real world changes in approach that are common and can
be assigned on short notice. Once again, the analog crews
transitioned more easily to the parallel runway’s localizer,
whereas the EFIS crews had a much more difficult time, with
the pilot going head down for a significant amount of time
trying to program the new approach into the FMS.

17-27

33 N 324 W 30 6 E 12

GSS 2115
NAV
OBS

33 N 3

24 W 30 6 E 12

OBS S 21 15

33 N 3

24 W 30 6 E 12

HDG 15 S 21

NAV1 108.00 113.00 WPT _ _ _ _ _ _ DIS _ _ ._ NM DTK _ _ _° TRK 360° 134.000 118.000 COM1
NAV2 108.00 110.60 123.800 118.000 COM2

130 44030000 2
4200
120
270° 4100 1
1110 60
100 VOR 1 1
44000000 2
9 20
3900
90
3800
80
4300
70TAS 106KT

OAT 7°C

XPDR 5537 IDNT LCL 10:12:34
ALERTS

FFigiguurere171-61-91.1T.wFoigsuimreil1a6r-f1li1ghiltlduesctrkasteqsutiwpopesdimwiiltahrthcoecskapmitesienqfourimppaetidonwtiwthotdhieffsearmenet winafoyrs,maantaiolongtwanodddiifgfeitraeln.tWwhaaytsa,raentahleoyginodnicthaetinlegf?t
Cahnadncdeigsiatarel othnatthteheriagnhat.loWg hpailtoat rweiltlhreeyviinewdicthaetitnogp?diCsphlaanycbeesfaorree tthhaetbtohtetoamnadliosgplpaiyl.oCt wonilvlerresveileyw, ththeeddigisiptalallyy otrnaitnheedlepfitlobtewfoirlel rtehveiew
thdeisipnlsatryuomnetnhtepraingehlt.oCnotnhveebrosettloymthfeirdsitg. itally trained pilot will review the instrument panel on the right side first.
17-28

Equipment Use Respect for Onboard Systems
Autopilot Systems
Automation can assist the pilot in many ways, but a thorough
In a single-pilot environment, an autopilot system can greatly understanding of the system(s) in use is essential to gaining
reduce workload. [Figure 17-20] As a result, the pilot is free the benefits it can offer. Understanding leads to respect
to focus his or her attention on other flight deck duties. This which is achieved through discipline and the mastery of the
can improve situational awareness and reduce the possibility onboard systems. It is important to fly the airplane using
of a CFIT accident. While the addition of an autopilot may minimal information from the primary flight display (PFD).
certainly be considered a risk control measure, the real This includes turns, climbs, descents, and being able to fly
challenge comes in determining the impact of an inoperative approaches.
unit. If the autopilot is known to be inoperative prior to
departure, this may factor into the evaluation other risks. Reinforcement of Onboard Suites

The use of an electronic flight display may not seem
intuitive, but competency becomes better with understanding
and practice. Computer-based software and incremental
training help the pilot become comfortable with the onboard
suites. Then the pilot needs to practice what was learned
in order to gain experience. Reinforcement not only yields
dividends in the use of automation, it also reduces workload
significantly.

Figure 17-20. An example of an autopilot system. Getting Beyond Rote Workmanship
The key to working effectively with automation is getting
For example, the pilot may be planning for a VHF beyond the sequential process of executing an action. If a
omnidirectional range (VOR) approach down to minimums pilot has to analyze what key to push next, or always uses
on a dark night into an unfamiliar airport. In such a case, the the same sequence of keystrokes when others are available,
pilot may have been relying heavily on a functioning autopilot he or she may be trapped in a rote process. This mechanical
capable of flying a coupled approach. This would free the process indicates a shallow understanding of the system.
pilot to monitor aircraft performance. A malfunctioning Again, the desire is to become competent and know what to
autopilot could be the single factor that takes this from a do without having to think about,“what keystroke is next.”
medium to a serious risk. At this point, an alternative needs Operating the system with competency and comprehension
to be considered. On the other hand, if the autopilot were to benefits a pilot when situations become more diverse and
fail at a critical (high workload) portion of this same flight, tasks increase.
the pilot must be prepared to take action. Instead of simply
being an inconvenience, this could quickly turn into an Understand the Platform
emergency if not properly handled. The best way to ensure Contrary to popular belief, flight in aircraft equipped with
a pilot is prepared for such an event is to carefully study the different electronic management suites requires the same
issue prior to departure and determine well in advance how attention as aircraft equipped with analog instrumentation
an autopilot failure is to be handled. and a conventional suite of avionics. The pilot should review
and understand the different ways in which EFD are used in
Familiarity a particular aircraft. [Figure 17-21]
As previously discussed, pilot familiarity with all equipment
is critical in optimizing both safety and efficiency. If a pilot is Two simple rules for use of an EFD:
unfamiliar with any aircraft systems, this will add to workload
and may contribute to a loss of situational awareness. This • Be able to fly the aircraft to the standards in the PTS.
level of proficiency is critical and should be looked upon Although this may seem insignificant, knowing how to
as a requirement, not unlike carrying an adequate supply of fly the aircraft to a standard makes a pilot’s airmanship
fuel. As a result, pilots should not look upon unfamiliarity smoother and allows him or her more time to attend
with the aircraft and its systems as a risk control measure, to the system instead of managing multiple tasks.
but instead as a hazard with high risk potential. Discipline
is key to success. • Read and understand the installed electronic flight
systems manuals to include the use of the autopilot
and the other onboard electronic management tools.

17-29

advanced avionics aircraft Safety Study found that poor
decision-making seems to afflict new advanced avionics
pilots at a rate higher than that of GA as a whole. The review
of advanced avionics accidents cited in this study shows the
majority are not caused by something directly related to the
aircraft, but by the pilot’s lack of experience and a chain of
poor decisions. One consistent theme in many of the fatal
accidents is continued VFR flight into IMC.

Thus, pilot skills for normal and emergency operations hinge
not only on mechanical manipulation of the stick and rudder,
but also include the mental mastery of the EFD. Three key
flight management skills are needed to fly the advanced
avionics safely: information, automation, and risk.

Information Management
For the newly transitioning pilot, the PFD, MFD, and GPS/
VHF navigator screens seem to offer too much information
presented in colorful menus and submenus. In fact, the pilot
may be drowning in information but unable to find a specific
piece of information. It might be helpful to remember these
systems are similar to computers which store some folders
on a desktop and some within a hierarchy.

The first critical information management skill for flying with
advanced avionics is to understand the system at a conceptual
level. Remembering how the system is organized helps the
pilot manage the available information. It is important to
understanding that learning knob-and-dial procedures is not
enough. Learning more about how advanced avionics systems
work leads to better memory for procedures and allows pilots
to solve problems they have not seen before.

Figure 17-21. Examples of different platforms. Top to bottom are the There are also limits to understanding. It is generally
Beechcraft Baron G58, Cirrus SR22, and Cirrus Entega. impossible to understand all of the behaviors of a complex
avionics system. Knowing to expect surprises, and to
Managing Aircraft Automation continually learn new things is more effective than attempting
Before any pilot can master aircraft automation, he or she to memorize mechanical manipulation of the knobs.
must first know how to fly the aircraft. Maneuvers training Simulation software and books on the specific system used
remains an important component of flight training because are of great value.
almost 40 percent of all GA accidents take place in the
landing phase, one realm of flight that still does not involve The second critical information management skill is stop,
programming a computer to execute. Another 15 percent of look, and read. Pilots new to advanced avionics often become
all GA accidents occurs during takeoff and initial climb. fixated on the knobs and try to memorize each and every
sequence of button pushes, pulls, and turns. A far better
An advanced avionics safety issue identified by the FAA strategy for accessing and managing the information available
concerns pilots who apparently develop an unwarranted over- in advanced avionics computers is to stop, look, and read.
reliance in their avionics and the aircraft, believing that the Reading before pushing, pulling, or twisting can often save
equipment will compensate for pilot shortcomings. Related a pilot some trouble.
to the over-reliance is the role of ADM, which is probably
the most significant factor in the GA accident record of high Once behind the display screens on an advanced avionics
performance aircraft used for cross country flight. The FAA aircraft, the pilot’s goal is to meter, manage, and prioritize the

17-30

information flow to accomplish specific tasks. Certificated into the navigation system? Callouts—even for single-pilot
flight instructors (CFIs) as well as pilots transitioning to operations—are an excellent way to maintain situational
advanced avionics will find it helpful to corral the information awareness as well as manage information.
flow. This is possible through such tactics as configuring the
aspects of the PFD and MFD screens according to personal Other ways to maintain situational awareness include:
preferences. For example, most systems offer map orientation
options that include “north up,” “track up,” “DTK” (desired • Perform verification check of all programming. Before
track up), and “heading up.” Another tactic is to decide, when departure, check all information programmed while
possible, how much (or how little) information to display. on the ground.
Pilots can also tailor the information displayed to suit the
needs of a specific flight. • Check the flight routing. Before departure, ensure all
routing matches the planned flight route. Enter the
Information flow can also be managed for a specific planned route and legs, to include headings and leg
operation. The pilot has the ability to prioritize information length, on a paper log. Use this log to evaluate what
for a timely display of exactly the information needed for any has been programmed. If the two do not match, do not
given flight operation. Examples of managing information assume the computer data is correct, double check the
display for a specific operation include: computer entry.

• Program map scale settings for en route versus • Verify waypoints.
terminal area operation.
• Make use of all onboard navigation equipment. For
• Utilize the terrain awareness page on the MFD for a example, use VOR to back up GPS and vice versa.
night or IMC flight in or near the mountains.
• Match the use of the automated system with pilot
• Use the nearest airports inset on the PFD at night or proficiency. Stay within personal limitations.
over inhospitable terrain.
• Plan a realistic flight route to maintain situational
• Program the weather datalink set to show echoes and awareness. For example, although the onboard
METAR status flags. equipment allows a direct flight from Denver,
Colorado, to Destin, Florida, the likelihood of
Enhanced Situational Awareness rerouting around Eglin Air Force Base’s airspace is
An advanced avionics aircraft offers increased safety with high.
enhanced situational awareness. Although aircraft flight
manuals (AFM) explicitly prohibit using the moving map, • Be ready to verify computer data entries. For example,
topography, terrain awareness, traffic, and weather datalink incorrect keystrokes could lead to loss of situational
displays as the primary data source, these tools nonetheless awareness because the pilot may not recognize errors
give the pilot unprecedented information for enhanced made during a high workload period.
situational awareness. Without a well-planned information
management strategy, these tools also make it easy for an Automation Management
unwary pilot to slide into the complacent role of passenger Advanced avionics offer multiple levels of automation, from
in command. strictly manual flight to highly automated flight. No one level
of automation is appropriate for all flight situations, but in
Consider the pilot whose navigational information order to avoid potentially dangerous distractions when flying
management strategy consists solely of following the with advanced avionics, the pilot must know how to manage
magenta line on the moving map. He or she can easily fly the course deviation indicator (CDI), the navigation source,
into geographic or regulatory disaster, if the straight-line GPS and the autopilot. It is important for a pilot to know the
course goes through high terrain or prohibited airspace, or if peculiarities of the particular automated system being used.
the moving map display fails. This ensures the pilot knows what to expect, how to monitor
for proper operation, and promptly take appropriate action if
the system does not perform as expected.

A good strategy for maintaining situational awareness For example, at the most basic level, managing the autopilot
information management should include practices that help means knowing at all times which modes are engaged
ensure that awareness is enhanced by the use of automation, and which modes are armed to engage. The pilot needs to
not diminished. Two basic procedures are to always double- verify that armed functions (e.g., navigation tracking or
check the system and verbal callouts. At a minimum, ensure altitude capture) engage at the appropriate time. Automation
the presentation makes sense. Was the correct destination fed management is another good place to practice the callout

17-31

technique, especially after arming the system to make a In Colombia, a multi-engine aircraft crewed with two pilots
change in course or altitude. struck the face of the Andes Mountains. Examination of
their FMS revealed they entered a waypoint into the FMS
In advanced avionics aircraft, proper automation management incorrectly by one degree resulting in a flightpath taking
also requires a thorough understanding of how the autopilot them to a point 60 NM off their intended course. The pilots
interacts with the other systems. For example, with some were equipped with the proper charts, their route was posted
autopilots, changing the navigation source on the e-HSI from on the charts, and they had a paper navigation log indicating
GPS to LOC or VOR while the autopilot is engaged in NAV the direction of each leg. They had all the tools to manage
(course tracking mode) will cause the autopilot’s NAV mode and monitor their flight, but instead allowed the automation
to disengage. The autopilot’s lateral control will default to to fly and manage itself. The system did exactly what it was
ROL (wing level) until the pilot takes action to reengage the programmed to do; it flew on a programmed course into a
NAV mode to track the desired navigation source. mountain resulting in multiple deaths. The pilots simply failed
to manage the system and inherently created their own hazard.
Risk Management Although this hazard was self-induced, what is notable is
the risk the pilots created through their own inattention.
Risk management is the last of the three flight management By failing to evaluate each turn made at the direction of
skills needed for mastery of the glass flight deck aircraft. The automation, the pilots maximized risk instead of minimizing
enhanced situational awareness and automation capabilities it. In this case, a totally avoidable accident become a tragedy
offered by a glass flight deck airplane vastly expand its safety through simple pilot error and complacency.
and utility, especially for personal transportation use. At the
same time, there is some risk that lighter workloads could For the GA pilot transitioning to automated systems, it is
lead to complacency. helpful to note that all human activity involving technical
devices entails some element of risk. Knowledge, experience,
Humans are characteristically poor monitors of automated and mission requirements tilt the odds in favor of safe and
systems. When asked to passively monitor an automated successful flights. The advanced avionics aircraft offers
system for faults, abnormalities, or other infrequent events, many new capabilities and simplifies the basic flying tasks,
humans perform poorly. The more reliable the system, the but only if the pilot is properly trained and all the equipment
poorer the human performance. For example, the pilot only is working as advertised.
monitors a backup alert system, rather than the situation
that the alert system is designed to safeguard. It is a paradox Chapter Summary
of automation that technically advanced avionics can both
increase and decrease pilot awareness. This chapter focused on helping the pilot improve his or
her ADM skills with the goal of mitigating the risk factors
It is important to remember that electronic flight displays do associated with flight in both classic and automated aircraft.
not replace basic flight knowledge and skills. They are a tool In the end, the discussion is not so much about aircraft, but
for improving flight safety. Risk increases when the pilot about the people who fly them.
believes the gadgets will compensate for lack of skill and
knowledge. It is especially important to recognize there are
limits to what the electronic systems in any light GA aircraft
can do. Being PIC requires sound ADM which sometimes
means saying “no” to a flight.

Risk is also increased when the pilot fails to monitor the
systems. By failing to monitor the systems and failing to
check the results of the processes, the pilot becomes detached
from the aircraft operation and slides into the complacent role
of passenger in command. Complacency led to tragedy in a
1999 aircraft accident.

17-32

Appendix

Short Field Takeoff Distance at 2,450 Pounds for a Cessna Model 172R

A-1

Time, Fuel, and Distance to Climb at 2,450 Pounds for a Cessna Model 172R

A-2

Cruise Performance for a Cessna Model 172R

A-3

Short Field Landing Distance at 2,450 Pounds for a Cessna Model 172R

A-4

Challenger 605 Range/Payload Profile

Takeoff Field Length (feet) Fuel 3,190 6,570 10,230 14,200 18,105
Burn (lb) 4:00 6:00 8:00 9:50

SL 5,000 ft Gross Time (hour) 2:00
ISA ISA +20°C Takeoff
Weight (lb)
5,840 9,400
50,000

4,940 7,755 46,000

4,219 6,432 40,000

3,600 5,234 35,000 Max Zero Payload Conditions: 26,985 lb BOW, M 0.74
3,465 4,804 30,000 Payload cruise speed, ISA, zero wind, NBAA
3,000 lb 1,000 1,500
3,401 4,535 Payload IFR reserves (200 NM)

1,000 lb Note: Fuel burn figures provided on
Payload top of graph are based on 1,000 lb
payload performance computations.
0 500
2,000 2,500 3,000 3,500 4,000 4,500
Range (NM)

A-5

Challenger 605 Time and Fuel Versus Distance

CHALLENGER 605 TIME AND FUEL VERSUS DISTANCE

4,500 M0.80 Cruise Speed 3,700 NM 4,045 NM
4,000 M0.74 Cruise Speed 3,512 NM 18,105 lb 18,105 lb
3,500 16,820 lb
3,000
Distance (NM) 2,500 2,599 NM 3,272 NM
2,000 11,980 lb 14,200 lb
1,500
1,000 771 NM 1,685 NM 2,424 NM
3,550 lb 7,570 lb 10,230 lb
500
0 730 NM 1,577 NM Conditions: 26,985 lb BOW, 1,000
0:00 3,190 lb 6,570 lb lb payload, ISA, zero wind, NBAA

IFR reserves (200 NM)

1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00
Time (hour)

M0.80 Cruise Speed Time 0:00 2:00 4:00 6:00 8:00 8:25
Distance (NM) 0 771 1,685 2,599 3,512 3,701
Fuel (lb) 0 3,550 7,570 11,980 16,820 18,105

M0.74 Cruise Speed Time 0:00 2:00 4:00 6:00 8:00 9:50
Distance (NM) 0 730 1,577 2,424 3,272 4,045
Fuel (lb) 0 3,190 6,570 10,230 14,200 18,105

Conditions: 1,000 lb payload, ISA, zero wind, NBAA IFR reserves (200 NM alternate), 26,985 lb BOW

Note: All Challenger 605 performance data are for discussion purposes only. By this document, Bombardier Inc.,
does not intend to make, and is not making, any offer, commitment, representation or warranty of any kind whatsoever.

All data are subject to change without prior notice.

A-6

Challenger 605 Time and Fuel Versus Distance

CHALLENGER 605 SPECIFIC RANGE

0.240

Specific Range (NM/lb) 0.230 M 0.74 FL 390
0.220 Cruise Speed FL 370
0.210
0.200 FL 350 M 0.80 Cruise Speed
0.190 M 0.82 Cruise Speed
0.180 FL 330
470 480 490
FL 310

0.170

0.160 Conditions: 40,000 lb mid-cruise weight, zero wind, ISA

0.150 430 440 450 460
420 Speed (KTAS)

Plotting of constant FL lines M0.82 M0.80 M0.74
Flight Level
290 Speed
Spc Range 481 469 434
310 Speed 0.165 0.178 0.199
Spc Range
477 465 430
330 Speed 0.174 0.188 0.208
Spc Range
350 Speed 473 461 427
Spc Range 0.181 0.197 0.216

370 Speed 470 459 424
Spc Range 0.185 0.204 0.222

390 Speed 459 424
Spc Range 0.205 0.223

Plotting of Long Range Cruise and High Speed Cruise lines

M0.74 "X" FL290 FL310 FL330 FL350 FL370 FL390
M0.74 "Y" 434 430 427 424 424

0.199 0.208 0.216 0.222 0.223

M0.80 "X" 469 465 461 459 459
M0.80 "Y" 0.178 0.188 0.197 0.204 0.205

M0.82 "X" 481 477 473 470
M0.82 "Y" 0.165 0.174 0.181 0.185

Note: Based on 40,000 lb mid-cruise weight, ISA Conditions, zero wind

Note: All Challenger 605 performance data are for discussion purposes only. By this document, Bombardier Inc.,
does not intend to make, and is not making, any offer, commitment, representation or warranty of any kind whatsoever.

All data are subject to change without prior notice.

A-7

A-8

Glossary

14 CFR. See Title 14 of the Code of Federal Regulations. ADF. See automatic direction finder.

100-hour inspection. An inspection identical in scope to ADI. See attitude director indicator.
an annual inspection. Conducted every 100 hours of flight
on aircraft of under 12,500 pounds that are used to carry Adiabatic cooling. A process of cooling the air through
passengers for hire. expansion. For example, as air moves up slope it expands
with the reduction of atmospheric pressure and cools as it
Absolute accuracy. The ability to determine present position expands.
in space independently, and is most often used by pilots.
Adiabatic heating. A process of heating dry air through
Absolute altitude. The actual distance between an aircraft compression. For example, as air moves down a slope it is
and the terrain over which it is flying. compressed, which results in an increase in temperature.

Absolute pressure. Pressure measured from the reference Adjustable-pitch propeller. A propeller with blades whose
of zero pressure, or a vacuum. pitch can be adjusted on the ground with the engine not
running, but which cannot be adjusted in flight. Also referred
A.C. Alternating current. to as a ground adjustable propeller. Sometimes also used
to refer to constant-speed propellers that are adjustable in
Acceleration. Force involved in overcoming inertia, and flight.
which may be defined as a change in velocity per unit of
time. Adjustable stabilizer. A stabilizer that can be adjusted in
flight to trim the airplane, thereby allowing the airplane to
Acceleration error. A magnetic compass error apparent when fly hands-off at any given airspeed.
the aircraft accelerates while flying on an easterly or westerly
heading, causing the compass card to rotate toward North. ADM. See aeronautical decision-making.

Accelerate-go distance. The distance required to accelerate ADS-B. See automatic dependent surveillance-broadcast.
to V1 with all engines at takeoff power, experience an engine
failure at V1, and continue the takeoff on the remaining Advection fog. Fog resulting from the movement of warm,
engine(s). The runway required includes the distance humid air over a cold surface.
required to climb to 35 feet by which time V2 speed must
be attained. Adverse yaw. A condition of flight in which the nose of an
airplane tends to yaw toward the outside of the turn. This is
Accelerate-stop distance. The distance required to accelerate caused by the higher induced drag on the outside wing, which
to V1 with all engines at takeoff power, experience an engine is also producing more lift. Induced drag is a by-product of
failure at V1, and abort the takeoff and bring the airplane to the lift associated with the outside wing.
a stop using braking action only (use of thrust reversing is
not considered). Aerodynamics. The science of the action of air on an object,
and with the motion of air on other gases. Aerodynamics
Accelerometer. A part of an inertial navigation system deals with the production of lift by the aircraft, the relative
(INS) that accurately measures the force of acceleration in wind, and the atmosphere.
one direction.

ADC. See air data computer.

G-1

Aeronautical chart. A map used in air navigation containing Airplane Flight Manual (AFM). A document developed
all or part of the following: topographic features, hazards and by the airplane manufacturer and approved by the Federal
obstructions, navigation aids, navigation routes, designated Aviation Administration (FAA). It is specific to a particular
airspace, and airports. make and model airplane by serial number and it contains
operating procedures and limitations.
Aeronautical decision-making (ADM). A systematic
approach to the mental process used by pilots to consistently Airplane Owner/Information Manual. A document
determine the best course of action in response to a given developed by the airplane manufacturer containing general
set of circumstances. information about the make and model of an airplane. The
airplane owner’s manual is not FAA approved and is not
A/FD. See Airport/Facility Directory. specific to a particular serial numbered airplane. This manual
is not kept current, and therefore cannot be substituted for
Agonic line. An irregular imaginary line across the surface of the AFM/POH.
the Earth along which the magnetic and geographic poles are in
alignment, and along which there is no magnetic variation. Airport diagram. The section of an instrument approach
procedure chart that shows a detailed diagram of the
Ailerons. Primary flight control surfaces mounted on the airport. This diagram includes surface features and airport
trailing edge of an airplane wing, near the tip. Ailerons control configuration information.
roll about the longitudinal axis.
Airport/Facility Directory (A/FD). An FAA publication
Aircraft. A device that is used, or intended to be used, for containing information on all airports, communications,
flight. and NAVAIDs.

Aircraft altitude. The actual height above sea level at which Airport surface detection equipment (ASDE). Radar
the aircraft is flying. equipment specifically designed to detect all principal
features and traffic on the surface of an airport, presenting the
Aircraft approach category. A performance grouping of entire image on the control tower console; used to augment
aircraft based on a speed of 1.3 times the stall speed in the visual observation by tower personnel of aircraft and/or
landing configuration at maximum gross landing weight. vehicular movements on runways and taxiways.

Air data computer (ADC). An aircraft computer that Airport surveillance radar (ASR). Approach control
receives and processes pitot pressure, static pressure, and radar used to detect and display an aircraft’s position in the
temperature to calculate very precise altitude, indicated terminal area.
airspeed, true airspeed, and air temperature.
Airport surveillance radar approach. An instrument
Airfoil. Any surface, such as a wing, propeller, rudder, or approach in which ATC issues instructions for pilot
even a trim tab, which provides aerodynamic force when it compliance based on aircraft position in relation to the final
interacts with a moving stream of air. approach course and the distance from the end of the runway
as displayed on the controller’s radar scope.
Air mass. An extensive body of air having fairly uniform
properties of temperature and moisture. Air route surveillance radar (ARSR). Air route traffic
control center (ARTCC) radar used primarily to detect
AIRMET. Inflight weather advisory issued as an amendment and display an aircraft’s position while en route between
to the area forecast, concerning weather phenomena of terminal areas.
operational interest to all aircraft and that is potentially
hazardous to aircraft with limited capability due to lack of Air route traffic control center (ARTCC). Provides ATC
equipment, instrumentation, or pilot qualifications. service to aircraft operating on IFR flight plans within
controlled airspace and principally during the en route phase
Airplane. An engine-driven, fixed-wing aircraft heavier than of flight.
air that is supported in flight by the dynamic reaction of air
against its wings. Airspeed. Rate of the aircraft’s progress through the air.

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Airspeed indicator. A differential pressure gauge that Alternate static source valve. A valve in the instrument static
measures the dynamic pressure of the air through which the air system that supplies reference air pressure to the altimeter,
aircraft is flying. Displays the craft’s airspeed, typically in airspeed indicator, and vertical speed indicator if the normal
knots, to the pilot. static pickup should become clogged or iced over.

Air traffic control radar beacon system (ATCRBS). Altimeter. A flight instrument that indicates altitude by
Sometimes called secondary surveillance radar (SSR), which sensing pressure changes.
utilizes a transponder in the aircraft. The ground equipment is
an interrogating unit, in which the beacon antenna is mounted Altimeter setting. Station pressure (the barometric pressure
so it rotates with the surveillance antenna. The interrogating at the location the reading is taken) which has been corrected
unit transmits a coded pulse sequence that actuates the aircraft for the height of the station above sea level.
transponder. The transponder answers the coded sequence by
transmitting a preselected coded sequence back to the ground Altitude engine. A reciprocating aircraft engine having a
equipment, providing a strong return signal and positive rated takeoff power that is producible from sea level to an
aircraft identification, as well as other special data. established higher altitude.

Airway. An airway is based on a centerline that extends from Ambient pressure. The pressure in the area immediately
one navigation aid or intersection to another navigation aid surrounding the aircraft.
(or through several navigation aids or intersections); used
to establish a known route for en route procedures between Ambient temperature. The temperature in the area
terminal areas. immediately surrounding the aircraft.

Airworthiness Certificate. A certificate issued by the FAA AME. See aviation medical examiner.
to all aircraft that have been proven to meet the minimum
standards set down by the Code of Federal Regulations. Amendment status. The circulation date and revision
number of an instrument approach procedure, printed above
Airworthiness Directive. A regulatory notice sent out by the procedure identification.
the FAA to the registered owner of an aircraft informing the
owner of a condition that prevents the aircraft from continuing Ammeter. An instrument installed in series with an electrical
to meet its conditions for airworthiness. Airworthiness load used to measure the amount of current flowing through
Directives (AD notes) are to be complied with within the the load.
required time limit, and the fact of compliance, the date of
compliance, and the method of compliance are recorded in Aneroid. The sensitive component in an altimeter or
the aircraft’s maintenance records. barometer that measures the absolute pressure of the air.
It is a sealed, flat capsule made of thin disks of corrugated
Alert area. An area in which there is a high volume of pilot metal soldered together and evacuated by pumping all of
training or an unusual type of aeronautical activity. the air out of it.

Almanac data. Information the global positioning system Aneroid barometer. An instrument that measures the
(GPS) receiver can obtain from one satellite which describes absolute pressure of the atmosphere by balancing the weight
the approximate orbital positioning of all satellites in the of the air above it against the spring action of the aneroid.
constellation. This information is necessary for the GPS
receiver to know what satellites to look for in the sky at a Angle of attack. The acute angle formed between the
given time. chord line of an airfoil and the direction of the air striking
the airfoil.
ALS. See approach lighting system.
Angle of incidence. The angle formed by the chord line of
Alternate airport. An airport designated in an IFR flight the wing and a line parallel to the longitudinal axis of the
plan, providing a suitable destination if a landing at the airplane.
intended airport becomes inadvisable.

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Anhedral. A downward slant from root to tip of an aircraft’s The P-factor would be to the right if the aircraft had a

wing or horizontal tail surface. counterclockwise rotating propeller.

Annual inspection. A complete inspection of an aircraft and ATC. Air Traffic Control.
engine, required by the Code of Federal Regulations, to be ATCRBS. See air traffic control radar beacon system.
accomplished every 12 calendar months on all certificated ATIS. See automatic terminal information service.
aircraft. Only an A&P technician holding an Inspection
Authorization can conduct an annual inspection.

Anti-ice. Preventing the accumulation of ice on an aircraft Atmospheric propagation delay. A bending of the
structure via a system designed for that purpose. electromagnetic (EM) wave from the satellite that creates
an error in the GPS system.
Antiservo tab. An adjustable tab attached to the trailing edge
of a stabilator that moves in the same direction as the primary Attitude. A personal motivational predisposition to respond
control. It is used to make the stabilator less sensitive. to persons, situations, or events in a given manner that can,
nevertheless, be changed or modified through training as sort
Approach lighting system (ALS). Provides lights that will of a mental shortcut to decision-making.
penetrate the atmosphere far enough from touchdown to
give directional, distance, and glidepath information for safe Attitude and heading reference system (AHRS). A system
transition from instrument to visual flight. composed of three-axis sensors that provide heading, attitude,
and yaw information for aircraft. AHRS are designed to
Area chart. Part of the low-altitude en route chart series, replace traditional mechanical gyroscopic flight instruments
this chart furnishes terminal data at a larger scale for and provide superior reliability and accuracy.
congested areas.
Attitude director indicator (ADI). An aircraft attitude
Area forecast (FA). A report that gives a picture of clouds, indicator that incorporates flight command bars to provide
general weather conditions, and visual meteorological pitch and roll commands.
conditions (VMC) expected over a large area encompassing
several states. Attitude indicator. The foundation for all instrument flight,
this instrument reflects the airplane’s attitude in relation to
Area navigation (RNAV). Allows a pilot to fly a selected the horizon.
course to a predetermined point without the need to overfly
ground-based navigation facilities, by using waypoints. Attitude instrument flying. Controlling the aircraft by
reference to the instruments rather than by outside visual
Arm. See moment arm. cues.

ARSR. See air route surveillance radar. Attitude management. The ability to recognize hazardous
attitudes in oneself and the willingness to modify them as
ARTCC. See air route traffic control center. necessary through the application of an appropriate antidote
thought.
ASDE. See airport surface detection equipment.
Autokinesis. Nighttime visual illusion that a stationary light
ASOS. See Automated Surface Observing System. is moving, which becomes apparent after several seconds of
staring at the light.
Aspect ratio. Span of a wing divided by its average chord.
Automated Surface Observing System (ASOS). Weather
ASR. See airport surveillance radar. reporting system which provides surface observations every
minute via digitized voice broadcasts and printed reports.
Asymmetric thrust. Also known as P-factor. A tendency for
an aircraft to yaw to the left due to the descending propeller Automated Weather Observing System (AWOS).
blade on the right producing more thrust than the ascending Automated weather reporting system consisting of various
blade on the left. This occurs when the aircraft’s longitudinal sensors, a processor, a computer-generated voice subsystem,
axis is in a climbing attitude in relation to the relative wind. and a transmitter to broadcast weather data.

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Automatic dependent surveillance—broadcast (ADS- Back course (BC). The reciprocal of the localizer course
B). A device used in aircraft that repeatedly broadcasts a for an ILS. When flying a back-course approach, an aircraft
message that includes position (such as latitude, longitude, approaches the instrument runway from the end at which the
localizer antennas are installed.
and altitude), velocity, and possibly other information.

Automatic direction finder (ADF). Electronic navigation Balance tab. An auxiliary control mounted on a primary
equipment that operates in the low- and medium-frequency control surface, which automatically moves in the direction
bands. Used in conjunction with the ground-based opposite the primary control to provide an aerodynamic
nondirectional beacon (NDB), the instrument displays the assist in the movement of the control. Sometimes referred
number of degrees clockwise from the nose of the aircraft to as a servo tab.
to the station being received.
Baro-aiding. A method of augmenting the GPS integrity
Automatic terminal information service (ATIS). The solution by using a nonsatellite input source. To ensure that
continuous broadcast of recorded non-control information in baro-aiding is available, the current altimeter setting must
selected terminal areas. Its purpose is to improve controller be entered as described in the operating manual.
effectiveness and relieve frequency congestion by automating
repetitive transmission of essential but routine information. Barometric scale. A scale on the dial of an altimeter to which
the pilot sets the barometric pressure level from which the
Autopilot. An automatic flight control system which keeps altitude shown by the pointers is measured.
an aircraft in level flight or on a set course. Automatic pilots
can be directed by the pilot, or they may be coupled to a Basic empty weight (GAMA). Basic empty weight
radio navigation signal. includes the standard empty weight plus optional and special
equipment that has been installed.
Aviation medical examiner (AME). A physician with
training in aviation medicine designated by the Civil BC. See back course.
Aerospace Medical Institute (CAMI).
Bernoulli’s Principle. A principle that explains how the
Aviation Routine Weather Report (METAR). Observation pressure of a moving fluid varies with its speed of motion.
of current surface weather reported in a standard international An increase in the speed of movement causes a decrease in
format. the fluid’s pressure.

AWOS. See Automated Weather Observing System. Biplanes. Airplanes with two sets of wings.

Axes of an aircraft. Three imaginary lines that pass through Block altitude. A block of altitudes assigned by ATC to
an aircraft’s center of gravity. The axes can be considered allow altitude deviations; for example, “Maintain block
as imaginary axles around which the aircraft rotates. The altitude 9 to 11 thousand.”
three axes pass through the center of gravity at 90° angles to
each other. The axis from nose to tail is the longitudinal axis Bypass ratio. The ratio of the mass airflow in pounds per
(pitch), the axis that passes from wingtip to wingtip is the second through the fan section of a turbofan engine to the
lateral axis (roll), and the axis that passes vertically through mass airflow that passes through the gas generator portion
the center of gravity is the vertical axis (yaw). of the engine.

Axial flow compressor. A type of compressor used in a Cabin altitude. Cabin pressure in terms of equivalent altitude
turbine engine in which the airflow through the compressor above sea level.
is essentially linear. An axial-flow compressor is made up of
several stages of alternate rotors and stators. The compressor Cage. The black markings on the ball instrument indicating
ratio is determined by the decrease in area of the succeeding its neutral position.
stages.
Calibrated. The instrument indication compared with a
Azimuth card. A card that may be set, gyroscopically standard value to determine the accuracy of the instrument.
controlled, or driven by a remote compass.

G-5

Calibrated orifice. A hole of specific diameter used to delay Center of pressure. A point along the wing chord line
the pressure change in the case of a vertical speed indicator. where lift is considered to be concentrated. For this reason,
the center of pressure is commonly referred to as the center
Calibrated airspeed. The speed at which the aircraft of lift.
is moving through the air, found by correcting IAS for
instrument and position errors. Centrifugal flow compressor. An impeller-shaped device
that receives air at its center and slings the air outward at high
Camber. The camber of an airfoil is the characteristic curve velocity into a diffuser for increased pressure. Also referred
of its upper and lower surfaces. The upper camber is more to as a radial outflow compressor.
pronounced, while the lower camber is comparatively flat.
This causes the velocity of the airflow immediately above the Centrifugal force. An outward force, that opposes centripetal
wing to be much higher than that below the wing. force, resulting from the effect of inertia during a turn.

Canard. A horizontal surface mounted ahead of the main Centripetal force. A center-seeking force directed inward
wing to provide longitudinal stability and control. It may toward the center of rotation created by the horizontal
be a fixed, movable, or variable geometry surface, with or component of lift in turning flight.
without control surfaces.
CG. See center of gravity.
Canard configuration. A configuration in which the span
of the forward wings is substantially less than that of the Changeover point (COP). A point along the route or
main wing. airway segment between two adjacent navigation facilities
or waypoints where changeover in navigation guidance
Cantilever. A wing designed to carry loads without external should occur.
struts.
Checklist. A tool that is used as a human factors aid in
CAS. Calibrated airspeed. aviation safety. It is a systematic and sequential list of all
operations that must be performed to properly accomplish
CDI. Course deviation indicator. a task.

Ceiling. The height above the earth’s surface of the lowest Chord line. An imaginary straight line drawn through an
layer of clouds, which is reported as broken or overcast, or airfoil from the leading edge to the trailing edge.
the vertical visibility into an obscuration.
Circling approach. A maneuver initiated by the pilot to
Center of gravity (CG). The point at which an airplane align the aircraft with a runway for landing when a straight-
would balance if it were possible to suspend it at that point. in landing from an instrument approach is not possible or is
It is the mass center of the airplane, or the theoretical point not desirable.
at which the entire weight of the airplane is assumed to
be concentrated. It may be expressed in inches from the Class A airspace. Airspace from 18,000 feet MSL up to and
reference datum, or in percentage of mean aerodynamic including FL 600, including the airspace overlying the waters
chord (MAC). The location depends on the distribution of within 12 NM of the coast of the 48 contiguous states and
weight in the airplane. Alaska; and designated international airspace beyond 12 NM
of the coast of the 48 contiguous states and Alaska within areas
Center of gravity limits. The specified forward and aft points of domestic radio navigational signal or ATC radar coverage,
within which the CG must be located during flight. These and within which domestic procedures are applied.
limits are indicated on pertinent airplane specifications.
Class B airspace. Airspace from the surface to 10,000 feet
Center of gravity range. The distance between the MSL surrounding the nation’s busiest airports in terms of
forward and aft CG limits indicated on pertinent airplane IFR operations or passenger numbers. The configuration of
specifications. each Class B airspace is individually tailored and consists

G-6

of a surface area and two or more layers, and is designed to Clear ice. Glossy, clear, or translucent ice formed by the
contain all published instrument procedures once an aircraft relatively slow freezing of large, supercooled water droplets.
enters the airspace. For all aircraft, an ATC clearance is
required to operate in the area, and aircraft so cleared receive Coefficient of lift. The ratio between lift pressure and
separation services within the airspace. dynamic pressure.

Class C airspace. Airspace from the surface to 4,000 feet Cold front. The boundary between two air masses where
above the airport elevation (charted in MSL) surrounding cold air is replacing warm air.
those airports having an operational control tower, serviced
by radar approach control, and having a certain number of IFR Compass course. A true course corrected for variation and
operations or passenger numbers. Although the configuration deviation errors.
of each Class C airspace area is individually tailored, the
airspace usually consists of a 5 NM radius core surface area Compass locator. A low-power, low- or medium-frequency
that extends from the surface up to 4,000 feet above the airport (L/MF) radio beacon installed at the site of the outer or middle
elevation, and a 10 NM radius shelf area that extends from marker of an ILS.
1,200 feet to 4,000 feet above the airport elevation.
Compass rose. A small circle graduated in 360° increments,
Class D airspace. Airspace from the surface to 2,500 feet to show direction expressed in degrees.
above the airport elevation (charted in MSL) surrounding
those airports that have an operational control tower. The Complex aircraft. An aircraft with retractable landing gear,
configuration of each Class D airspace area is individually flaps, and a controllable pitch propeller.
tailored, and when instrument procedures are published, the
airspace is normally designed to contain the procedures. Compressor pressure ratio. The ratio of compressor
discharge pressure to compressor inlet pressure.
Class E airspace. Airspace that is not Class A, Class B, Class
C, or Class D, and is controlled airspace. Compressor stall. In gas turbine engines, a condition in
an axial-flow compressor in which one or more stages of
Class G airspace. Airspace that is uncontrolled, except rotor blades fail to pass air smoothly to the succeeding
when associated with a temporary control tower, and has stages. A stall condition is caused by a pressure ratio that is
not been designated as Class A, Class B, Class C, Class D, incompatible with the engine rpm. Compressor stall will be
or Class E airspace. indicated by a rise in exhaust temperature or rpm fluctuation,
and if allowed to continue, may result in flameout and
Clean configuration. A configuration in which all flight physical damage to the engine.
control surfaces have been placed to create minimum drag.
In most aircraft this means flaps and gear retracted. Computer navigation fix. A point used to define a
navigation track for an airborne computer system such as
Clearance. ATC permission for an aircraft to proceed under GPS or FMS.
specified traffic conditions within controlled airspace, for the
purpose of providing separation between known aircraft. Concentric rings. Dashed-line circles depicted in the plan
view of IAP charts, outside of the reference circle, that show
Clearance delivery. Control tower position responsible for en route and feeder facilities.
transmitting departure clearances to IFR flights.
Condensation. A change of state of water from a gas (water
Clearance limit. The fix, point, or location to which an vapor) to a liquid.
aircraft is cleared when issued an air traffic clearance.
Condensation nuclei. Small particles of solid matter in the
Clearance on request. An IFR clearance not yet received air on which water vapor condenses.
after filing a flight plan.
Cone of confusion. A cone-shaped volume of airspace
Clearance void time. Used by ATC, the time at which the directly above a VOR station where no signal is received,
departure clearance is automatically canceled if takeoff has causing the CDI to fluctuate.
not been made. The pilot must obtain a new clearance or
cancel the IFR flight plan if not off by the specified time.

G-7

Configuration. This is a general term, which normally refers Coriolis illusion. The illusion of rotation or movement in an
to the position of the landing gear and flaps. entirely different axis, caused by an abrupt head movement,
while in a prolonged constant-rate turn that has ceased to
Constant-speed propeller. A controllable-pitch propeller stimulate the brain’s motion sensing system.
whose pitch is automatically varied in flight by a governor
to maintain a constant rpm in spite of varying air loads. Coupled ailerons and rudder. Rudder and ailerons are
connected with interconnected springs in order to counteract
Continuous flow oxygen system. System that supplies adverse yaw. Can be overridden if it becomes necessary to
a constant supply of pure oxygen to a rebreather bag that slip the aircraft.
dilutes the pure oxygen with exhaled gases and thus supplies a
healthy mix of oxygen and ambient air to the mask. Primarily Course. The intended direction of flight in the horizontal
used in passenger cabins of commercial airliners. plane measured in degrees from north.

Control and performance. A method of attitude instrument Cowl flaps. Shutter-like devices arranged around certain
flying in which one instrument is used for making attitude air-cooled engine cowlings, which may be opened or closed
changes, and the other instruments are used to monitor the to regulate the flow of air around the engine.
progress of the change.
Crew resource management (CRM). The application of
Control display unit. A display interfaced with the master team management concepts in the flight deck environment.
computer, providing the pilot with a single control point It was initially known as cockpit resource management,
for all navigations systems, thereby reducing the number of but as CRM programs evolved to include cabin crews,
required flight deck panels. maintenance personnel, and others, the phrase “crew
resource management” was adopted. This includes single
Controllability. A measure of the response of an aircraft pilots, as in most general aviation aircraft. Pilots of small
relative to the pilot’s flight control inputs. aircraft, as well as crews of larger aircraft, must make
effective use of all available resources; human resources,
Controlled airspace. An airspace of defined dimensions hardware, and information. A current definition includes
within which ATC service is provided to IFR and VFR flights all groups routinely working with the flight crew who
in accordance with the airspace classification. It includes are involved in decisions required to operate a flight
Class A, Class B, Class C, Class D, and Class E airspace. safely. These groups include, but are not limited to pilots,
dispatchers, cabin crewmembers, maintenance personnel,
Control pressures. The amount of physical exertion on the and air traffic controllers. CRM is one way of addressing
control column necessary to achieve the desired attitude. the challenge of optimizing the human/machine interface
and accompanying interpersonal activities.
Convective weather. Unstable, rising air found in
cumiliform clouds. Critical altitude. The maximum altitude under standard
atmospheric conditions at which a turbocharged engine can
Convective SIGMET. Weather advisory concerning produce its rated horsepower.
convective weather significant to the safety of all aircraft,
including thunderstorms, hail, and tornadoes. Critical angle of attack. The angle of attack at which
a wing stalls regardless of airspeed, flight attitude, or
Conventional landing gear. Landing gear employing a third weight.
rear-mounted wheel. These airplanes are also sometimes
referred to as tailwheel airplanes. Critical areas. Areas where disturbances to the ILS localizer
and glideslope courses may occur when surface vehicles or
Coordinated flight. Flight with a minimum disturbance of aircraft operate near the localizer or glideslope antennas.
the forces maintaining equilibrium, established via effective
control use. CRM. See crew resource management.

COP. See changeover point.

G-8

Cross-check. The first fundamental skill of instrument flight, Density altitude. Pressure altitude corrected for nonstandard
also known as “scan,” the continuous and logical observation temperature. Density altitude is used in computing the
of instruments for attitude and performance information. performance of an aircraft and its engines.

Cruise clearance. An ATC clearance issued to allow a Departure procedure (DP). Preplanned IFR ATC departure,
pilot to conduct flight at any altitude from the minimum published for pilot use, in textual and graphic format.
IFR altitude up to and including the altitude specified in the
clearance. Also authorizes a pilot to proceed to and make an Deposition. The direct transformation of a gas to a solid
approach at the destination airport. state, in which the liquid state is bypassed. Some sources use
sublimation to describe this process instead of deposition.
Current induction. An electrical current being induced into,
or generated in, any conductor that is crossed by lines of flux Detonation. The sudden release of heat energy from fuel in
from any magnet. an aircraft engine caused by the fuel-air mixture reaching
its critical pressure and temperature. Detonation occurs as a
DA. See decision altitude. violent explosion rather than a smooth burning process.

Datum (Reference Datum). An imaginary vertical plane Deviation. A magnetic compass error caused by local
or line from which all measurements of arm are taken. The magnetic fields within the aircraft. Deviation error is different
datum is established by the manufacturer. Once the datum on each heading.
has been selected, all moment arms and the location of CG
range are measured from this point. Dew. Moisture that has condensed from water vapor. Usually
found on cooler objects near the ground, such as grass, as
D.C. Direct current. the near-surface layer of air cools faster than the layers of
air above it.
Dark adaptation. Physical and chemical adjustments of the
eye that make vision possible in relative darkness. Dewpoint. The temperature at which air reaches a state where
it can hold no more water.
Dead reckoning. Navigation of an airplane solely by means
of computations based on airspeed, course, heading, wind DGPS. Differential global positioning system.
direction and speed, groundspeed, and elapsed time.
DH. See decision height.
Deceleration error. A magnetic compass error that occurs
when the aircraft decelerates while flying on an easterly Differential ailerons. Control surface rigged such that the
or westerly heading, causing the compass card to rotate aileron moving up moves a greater distance than the aileron
toward South. moving down. The up aileron produces extra parasite drag
to compensate for the additional induced drag caused by
Decision altitude (DA). A specified altitude in the precision the down aileron. This balancing of the drag forces helps
approach, charted in feet MSL, at which a missed approach minimize adverse yaw.
must be initiated if the required visual reference to continue
the approach has not been established. Differential Global Positioning System (DGPS). A system
that improves the accuracy of Global Navigation Satellite
Decision height (DH). A specified altitude in the precision Systems (GNSS) by measuring changes in variables to
approach, charted in height above threshold elevation, provide satellite positioning corrections.
at which a decision must be made either to continue the
approach or to execute a missed approach. Differential pressure. A difference between two pressures.
The measurement of airspeed is an example of the use of
Deice. The act of removing ice accumulation from an differential pressure.
aircraft structure.
Dihedral. The positive acute angle between the lateral
Delta. A Greek letter expressed by the symbol ∆ to indicate axis of an airplane and a line through the center of a wing
a change of values. As an example, ∆CG indicates a change or horizontal stabilizer. Dihedral contributes to the lateral
(or movement) of the CG. stability of an airplane.

G-9

Diluter-demand oxygen system. An oxygen system that Drag curve. The curve created when plotting induced drag
delivers oxygen mixed or diluted with air in order to maintain and parasite drag.
a constant oxygen partial pressure as the altitude changes.
Drift angle. Angle between heading and track.
Direct indication. The true and instantaneous reflection of
aircraft pitch-and-bank attitude by the miniature aircraft, DRVSM. See Domestic Reduced Vertical Separation
relative to the horizon bar of the attitude indicator. Minimum.

Direct User Access Terminal System (DUATS). A system DUATS. See direct user access terminal system.
that provides current FAA weather and flight plan filing
services to certified civil pilots, via personal computer, Duplex. Transmitting on one frequency and receiving on a
modem, or telephone access to the system. Pilots can request separate frequency.
specific types of weather briefings and other pertinent data
for planned flights. Dutch roll. A combination of rolling and yawing oscillations
that normally occurs when the dihedral effects of an aircraft
Directional stability. Stability about the vertical axis of an are more powerful than the directional stability. Usually
aircraft, whereby an aircraft tends to return, on its own, to dynamically stable but objectionable in an airplane because
flight aligned with the relative wind when disturbed from that of the oscillatory nature.
equilibrium state. The vertical tail is the primary contributor
to directional stability, causing an airplane in flight to align Dynamic hydroplaning. A condition that exists when
with the relative wind. landing on a surface with standing water deeper than the
tread depth of the tires. When the brakes are applied, there is
Distance circle. See reference circle. a possibility that the brake will lock up and the tire will ride
on the surface of the water, much like a water ski. When the
Distance measuring equipment (DME). A pulse-type tires are hydroplaning, directional control and braking action
electronic navigation system that shows the pilot, by an are virtually impossible. An effective anti-skid system can
instrument-panel indication, the number of nautical miles minimize the effects of hydroplaning.
between the aircraft and a ground station or waypoint.
Dynamic stability. The property of an aircraft that causes
DME. See distance measuring equipment. it, when disturbed from straight-and-level flight, to develop
forces or moments that restore the original condition of
DME arc. A flight track that is a constant distance from the straight and level.
station or waypoint.
Eddy currents. Current induced in a metal cup or disc when
DOD. Department of Defense. it is crossed by lines of flux from a moving magnet.

Doghouse. A turn-and-slip indicator dial mark in the shape Eddy current damping. The decreased amplitude of
of a doghouse. oscillations by the interaction of magnetic fields. In the case
of a vertical card magnetic compass, flux from the oscillating
Domestic Reduced Vertical Separation Minimum permanent magnet produces eddy currents in a damping disk
(DRVSM). Additional flight levels between FL 290 and FL or cup. The magnetic flux produced by the eddy currents
410 to provide operational, traffic, and airspace efficiency. opposes the flux from the permanent magnet and decreases
the oscillations.
Double gimbal. A type of mount used for the gyro in an
attitude instrument. The axes of the two gimbals are at right EFAS. See En Route Flight Advisory Service.
angles to the spin axis of the gyro, allowing free motion in
two planes around the gyro. EFC. See expect-further-clearance.

DP. See departure procedure. EFD. See electronic flight display.

Drag. The net aerodynamic force parallel to the relative EGT. See exhaust gas temperature.
wind, usually the sum of two components: induced drag
and parasite drag.

G-10

Electronic flight display (EFD). For the purpose of En route low-altitude charts. Aeronautical charts for en
standardization, any flight instrument display that uses LCD route IFR navigation below 18,000 feet MSL.
or other image-producing system (cathode ray tube (CRT),
etc.) EPR. See engine pressure ratio.

Elevator. The horizontal, movable primary control surface Equilibrium. A condition that exists within a body when the
in the tail section, or empennage, of an airplane. The sum of the moments of all of the forces acting on the body
elevator is hinged to the trailing edge of the fixed horizontal is equal to zero. In aerodynamics, equilibrium is when all
stabilizer. opposing forces acting on an aircraft are balanced (steady,
unaccelerated flight conditions).
Elevator illusion. The sensation of being in a climb or
descent, caused by the kind of abrupt vertical accelerations Equivalent airspeed. Airspeed equivalent to CAS in
that result from up- or downdrafts. standard atmosphere at sea level. As the airspeed and pressure
altitude increase, the CAS becomes higher than it should be,
Emergency. A distress or urgent condition. and a correction for compression must be subtracted from
the CAS.
Empennage. The section of the airplane that consists of the
vertical stabilizer, the horizontal stabilizer, and the associated Evaporation. The transformation of a liquid to a gaseous
control surfaces. state, such as the change of water to water vapor.

Emphasis error. The result of giving too much attention Exhaust gas temperature (EGT). The temperature of the
to a particular instrument during the cross-check, instead of exhaust gases as they leave the cylinders of a reciprocating
relying on a combination of instruments necessary for attitude engine or the turbine section of a turbine engine.
and performance information.
Expect-further-clearance (EFC). The time a pilot can
Empty-field myopia. Induced nearsightedness that is expect to receive clearance beyond a clearance limit.
associated with flying at night, in instrument meteorological
conditions and/or reduced visibility. With nothing to focus Explosive decompression. A change in cabin pressure faster
on, the eyes automatically focus on a point just slightly ahead than the lungs can decompress. Lung damage is possible.
of the airplane.
FA. See area forecast.
EM wave. Electromagnetic wave.
FAA. Federal Aviation Administration.
Encoding altimeter. A special type of pressure altimeter
used to send a signal to the air traffic controller on the ground, FAF. See final approach fix.
showing the pressure altitude the aircraft is flying.
False horizon. Inaccurate visual information for aligning the
Engine pressure ratio (EPR). The ratio of turbine discharge aircraft, caused by various natural and geometric formations
pressure divided by compressor inlet pressure, which is used that disorient the pilot from the actual horizon.
as an indication of the amount of thrust being developed by
a turbine engine. FDI. See flight director indicator.

En route facilities ring. Depicted in the plan view of IAP Federal airways. Class E airspace areas that extend upward
charts, a circle which designates NAVAIDs, fixes, and from 1,200 feet to, but not including, 18,000 feet MSL, unless
intersections that are part of the en route low altitude airway otherwise specified.
structure.
Feeder facilities. Used by ATC to direct aircraft to
En Route Flight Advisory Service (EFAS). An en route intervening fixes between the en route structure and the
weather-only AFSS service. initial approach fix.

En route high-altitude charts. Aeronautical charts for en Final approach. Part of an instrument approach
route instrument navigation at or above 18,000 feet MSL. procedure in which alignment and descent for landing are

accomplished.

G-11

Final approach fix (FAF). The fix from which the IFR Flight patterns. Basic maneuvers, flown by reference to the
final approach to an airport is executed, and which identifies instruments rather than outside visual cues, for the purpose
the beginning of the final approach segment. An FAF is of practicing basic attitude flying. The patterns simulate
designated on government charts by a Maltese cross symbol maneuvers encountered on instrument flights such as holding
for nonprecision approaches, and a lightning bolt symbol for patterns, procedure turns, and approaches.
precision approaches.
Flight strips. Paper strips containing instrument flight
Fixating. Staring at a single instrument, thereby interrupting information, used by ATC when processing flight plans.
the cross-check process.
FMS. See flight management system.
Fixed-pitch propellers. Propellers with fixed blade angles.
Fixed-pitch propellers are designed as climb propellers, FOD. See foreign object damage.
cruise propellers, or standard propellers.
Fog. Cloud consisting of numerous minute water droplets
Fixed slot. A fixed, nozzle shaped opening near the leading and based at the surface; droplets are small enough to be
edge of a wing that ducts air onto the top surface of the wing. suspended in the earth’s atmosphere indefinitely. (Unlike
Its purpose is to increase lift at higher angles of attack. drizzle, it does not fall to the surface. Fog differs from a
cloud only in that a cloud is not based at the surface, and is
FL. See flight level. distinguished from haze by its wetness and gray color.)

Flameout. A condition in the operation of a gas turbine Force (F). The energy applied to an object that attempts to
engine in which the fire in the engine goes out due to either cause the object to change its direction, speed, or motion.
too much or too little fuel sprayed into the combustors. In aerodynamics, it is expressed as F, T (thrust), L (lift), W
(weight), or D (drag), usually in pounds.
Flaps. Hinged portion of the trailing edge between the
ailerons and fuselage. In some aircraft ailerons and flaps are Foreign object damage (FOD). Damage to a gas turbine
interconnected to produce full-span “flaperons.” In either engine caused by some object being sucked into the engine
case, flaps change the lift and drag on the wing. while it is running. Debris from runways or taxiways can
cause foreign object damage during ground operations, and
Floor load limit. The maximum weight the floor can sustain the ingestion of ice and birds can cause FOD in flight.
per square inch/foot as provided by the manufacturer.
Form drag. The drag created because of the shape of a
Flight configurations. Adjusting the aircraft control surfaces component or the aircraft.
(including flaps and landing gear) in a manner that will
achieve a specified attitude. Frise-type aileron. Aileron having the nose portion
projecting ahead of the hinge line. When the trailing edge
Flight director indicator (FDI). One of the major components of the aileron moves up, the nose projects below the wing’s
of a flight director system, it provides steering commands that lower surface and produces some parasite drag, decreasing
the pilot (or the autopilot, if coupled) follows. the amount of adverse yaw.

Flight level (FL). A measure of altitude (in hundreds of feet) Front. The boundary between two different air masses.
used by aircraft flying above 18,000 feet with the altimeter
set at 29.92 "Hg. Frost. Ice crystal deposits formed by sublimation when
temperature and dewpoint are below freezing.
Flight management system (FMS). Provides pilot and crew
with highly accurate and automatic long-range navigation Fuel load. The expendable part of the load of the airplane.
capability, blending available inputs from long- and short- It includes only usable fuel, not fuel required to fill the lines
range sensors. or that which remains trapped in the tank sumps.

Flight path. The line, course, or track along which an aircraft Fundamental skills. Pilot skills of instrument cross-check,

is flying or is intended to be flown. instrument interpretation, and aircraft control.

G-12

Fuselage. The section of the airplane that consists of the GPS Approach Overlay Program. An authorization for
cabin and/or cockpit, containing seats for the occupants and pilots to use GPS avionics under IFR for flying designated
the controls for the airplane. existing nonprecision instrument approach procedures, with
the exception of LOC, LDA, and SDF procedures.
GAMA. General Aviation Manufacturers Association.
GPWS. See ground proximity warning system.
Gimbal ring. A type of support that allows an object, such
as a gyroscope, to remain in an upright condition when its Graveyard spiral. The illusion of the cessation of a turn
base is tilted. while still in a prolonged, coordinated, constant rate turn,
which can lead a disoriented pilot to a loss of control of the
Glideslope (GS). Part of the ILS that projects a radio beam aircraft.
upward at an angle of approximately 3° from the approach
end of an instrument runway. The glideslope provides Great circle route. The shortest distance across the surface
vertical guidance to aircraft on the final approach course for of a sphere (the Earth) between two points on the surface.
the aircraft to follow when making an ILS approach along
the localizer path. Ground adjustable trim tab. Non-movable metal trim tab
on a control surface. Bent in one direction or another while
Glideslope intercept altitude. The minimum altitude of an on the ground to apply trim forces to the control surface.
intermediate approach segment prescribed for a precision
approach that ensures obstacle clearance. Ground effect. The condition of slightly increased air
pressure below an airplane wing or helicopter rotor system
Global landing system (GLS). An instrument approach with that increases the amount of lift produced. It exists within
lateral and vertical guidance with integrity limits (similar to approximately one wing span or one rotor diameter from the
barometric vertical navigation (BARO VNAV). ground. It results from a reduction in upwash, downwash,
and wingtip vortices, and provides a corresponding decrease
Global navigation satellite system (GNSS). Satellite in induced drag.
navigation system that provides autonomous geospatial
positioning with global coverage. It allows small electronic Ground proximity warning system (GPWS). A system
receivers to determine their location (longitude, latitude, and designed to determine an aircraft’s clearance above the Earth
altitude) to within a few meters using time signals transmitted and provides limited predictability about aircraft position
along a line of sight by radio from satellites. relative to rising terrain.

Global positioning system (GPS). Navigation system Groundspeed. Speed over the ground, either closing speed to
that uses satellite rather than ground-based transmitters for the station or waypoint, or speed over the ground in whatever
location information. direction the aircraft is going at the moment, depending upon
the navigation system used.
GLS. See global landing system.
GS. See glideslope.
GNSS. See global navigation satellite system.
GWPS. See ground proximity warning system.
Goniometer. As used in radio frequency (RF) antenna
systems, a direction-sensing device consisting of two fixed Gyroscopic precession. An inherent quality of rotating
loops of wire oriented 90° from each other, which separately bodies, which causes an applied force to be manifested 90°
sense received signal strength and send those signals to two in the direction of rotation from the point where the force
rotors (also oriented 90°) in the sealed direction-indicating is applied.
instrument. The rotors are attached to the direction-indicating
needle of the instrument and rotated by a small motor until HAA. See height above airport.
minimum magnetic field is sensed near the rotors.
HAL. See height above landing.
GPS. See global positioning system.

G-13

HAT. See height above touchdown elevation. Histotoxic hypoxia. The inability of cells to effectively use
oxygen. Plenty of oxygen is being transported to the cells
Hazardous attitudes. Five aeronautical decision-making that need it, but they are unable to use it.
attitudes that may contribute to poor pilot judgment: anti-
authority, impulsivity, invulnerability, machismo, and HIWAS. See Hazardous Inflight Weather Advisory
resignation. Service.

Hazardous Inflight Weather Advisory Service (HIWAS). Holding. A predetermined maneuver that keeps aircraft
Service providing recorded weather forecasts broadcast to within a specified airspace while awaiting further clearance
airborne pilots over selected VORs. from ATC.

Head-up display (HUD). A special type of flight viewing Holding pattern. A racetrack pattern, involving two turns
screen that allows the pilot to watch the flight instruments and two legs, used to keep an aircraft within a prescribed
and other data while looking through the windshield of the airspace with respect to a geographic fix. A standard pattern
aircraft for other traffic, the approach lights, or the runway. uses right turns; nonstandard patterns use left turns.

Heading. The direction in which the nose of the aircraft is Homing. Flying the aircraft on any heading required to keep

pointing during flight. the needle pointing to the 0° relative bearing position.

Heading indicator. An instrument which senses airplane Horizontal situation indicator (HSI). A flight navigation
movement and displays heading based on a 360° azimuth, instrument that combines the heading indicator with a CDI,
with the final zero omitted. The heading indicator, also called in order to provide the pilot with better situational awareness
a directional gyro (DG), is fundamentally a mechanical of location with respect to the courseline.
instrument designed to facilitate the use of the magnetic
compass. The heading indicator is not affected by the forces Horsepower. The term, originated by inventor James Watt,
that make the magnetic compass difficult to interpret. means the amount of work a horse could do in one second.
One horsepower equals 550 foot-pounds per second, or
Headwork. Required to accomplish a conscious, rational 33,000 foot-pounds per minute.
thought process when making decisions. Good decision-
making involves risk identification and assessment, Hot start. In gas turbine engines, a start which occurs with
information processing, and problem solving. normal engine rotation, but exhaust temperature exceeds
prescribed limits. This is usually caused by an excessively
Height above airport (HAA). The height of the MDA above rich mixture in the combustor. The fuel to the engine must
the published airport elevation. be terminated immediately to prevent engine damage.

Height above landing (HAL). The height above a designated HSI. See horizontal situation indicator.
helicopter landing area used for helicopter instrument HUD. See head-up display.
approach procedures.

Height above touchdown elevation (HAT). The DA/DH or Human factors. A multidisciplinary field encompassing the
MDA above the highest runway elevation in the touchdown behavioral and social sciences, engineering, and physiology,
zone (first 3,000 feet of the runway). to consider the variables that influence individual and
crew performance for the purpose of optimizing human
HF. High frequency. performance and reducing errors.

Hg. Abbreviation for mercury, from the Latin Hung start. In gas turbine engines, a condition of normal
hydrargyrum. light off but with rpm remaining at some low value rather than
increasing to the normal idle rpm. This is often the result of
High performance aircraft. An aircraft with an engine of insufficient power to the engine from the starter. In the event
more than 200 horsepower. of a hung start, the engine should be shut down.

G-14

Hydroplaning. A condition that exists when landing on a ILS Category II: Provides for approach to a height
surface with standing water deeper than the tread depth of above touchdown of not less than 100 feet and with
the tires. When the brakes are applied, there is a possibility runway visual range of not less than 1,200 feet.
that the brake will lock up and the tire will ride on the
surface of the water, much like a water ski. When the tires ILS Category IIIA: Provides for approach without
are hydroplaning, directional control and braking action a decision height minimum and with runway visual
are virtually impossible. An effective anti-skid system can range of not less than 700 feet.
minimize the effects of hydroplaning.
ILS Category IIIB: Provides for approach without
Hypemic hypoxia. A type of hypoxia that is a result of a decision height minimum and with runway visual
oxygen deficiency in the blood, rather than a lack of inhaled range of not less than 150 feet.
oxygen. It can be caused by a variety of factors. Hypemic
means “not enough blood.” ILS Category IIIC: Provides for approach without a
decision height minimum and without runway visual
range minimum.

Hyperventilation. Occurs when an individual is experiencing IMC. See instrument meteorological conditions.
emotional stress, fright, or pain, and the breathing rate and
depth increase, although the carbon dioxide level in the Inclinometer. An instrument consisting of a curved glass
blood is already at a reduced level. The result is an excessive tube, housing a glass ball, and damped with a fluid similar
loss of carbon dioxide from the body, which can lead to to kerosene. It may be used to indicate inclination, as a level,
unconsciousness due to the respiratory system’s overriding or, as used in the turn indicators, to show the relationship
mechanism to regain control of breathing. between gravity and centrifugal force in a turn.

Hypoxia. A state of oxygen deficiency in the body sufficient Indicated airspeed (IAS). Shown on the dial of the
to impair functions of the brain and other organs. instrument airspeed indicator on an aircraft. Indicated
airspeed (IAS) is the airspeed indicator reading uncorrected
Hypoxic hypoxia. This type of hypoxia is a result of for instrument, position, and other errors. Indicated airspeed
insufficient oxygen available to the lungs. A decrease of means the speed of an aircraft as shown on its pitot static
oxygen molecules at sufficient pressure can lead to hypoxic airspeed indicator calibrated to reflect standard atmosphere
hypoxia. adiabatic compressible flow at sea level uncorrected for
airspeed system errors. Calibrated airspeed (CAS) is IAS
IAF. See initial approach fix. corrected for instrument errors, position error (due to
incorrect pressure at the static port) and installation errors.
IAP. See instrument approach procedures.
Indicated altitude. The altitude read directly from the
IAS. See indicated airspeed. altimeter (uncorrected) when it is set to the current altimeter
setting.
ICAO. See International Civil Aviation Organization.
Indirect indication. A reflection of aircraft pitch-and-bank
Ident. Air Traffic Control request for a pilot to push attitude by instruments other than the attitude indicator.
the button on the transponder to identify return on the
controller’s scope. Induced drag. Drag caused by the same factors that produce
lift; its amount varies inversely with airspeed. As airspeed
IFR. See instrument flight rules. decreases, the angle of attack must increase, in turn increasing
induced drag.
ILS. See instrument landing system.
Induction icing. A type of ice in the induction system that
ILS categories. Categories of instrument approach reduces the amount of air available for combustion. The most
procedures allowed at airports equipped with the following commonly found induction icing is carburetor icing.
types of instrument landing systems:
Inertial navigation system (INS). A computer-based
ILS Category I: Provides for approach to a height navigation system that tracks the movement of an aircraft
above touchdown of not less than 200 feet, and with via signals produced by onboard accelerometers. The initial
runway visual range of not less than 1,800 feet.

G-15

location of the aircraft is entered into the computer, and all Interference drag. Drag generated by the collision of
subsequent movement of the aircraft is sensed and used to airstreams creating eddy currents, turbulence, or restrictions
keep the position updated. An INS does not require any inputs to smooth flow.
from outside signals.
International Civil Aviation Organization (ICAO). The
Initial approach fix (IAF). The fix depicted on IAP charts United Nations agency for developing the principles and
where the instrument approach procedure (IAP) begins unless techniques of international air navigation, and fostering planning
otherwise authorized by ATC. and development of international civil air transport.

Inoperative components. Higher minimums are prescribed International standard atmosphere (IAS). A model of
when the specified visual aids are not functioning; this standard variation of pressure and temperature.
information is listed in the Inoperative Components Table found
in the United States Terminal Procedures Publications. Interpolation. The estimation of an intermediate value
of a quantity that falls between marked values in a series.
INS. See inertial navigation system. Example: In a measurement of length, with a rule that is
marked in eighths of an inch, the value falls between 3/8
Instantaneous vertical speed indicator (IVSI). Assists in inch and 1/2 inch. The estimated (interpolated) value might
interpretation by instantaneously indicating the rate of climb then be said to be 7/16 inch.
or descent at a given moment with little or no lag as displayed
in a vertical speed indicator (VSI). Inversion. An increase in temperature with altitude.

Instrument approach procedures (IAP). A series of Inversion illusion. The feeling that the aircraft is tumbling
predetermined maneuvers for the orderly transfer of an backwards, caused by an abrupt change from climb to straight-
aircraft under IFR from the beginning of the initial approach and-level flight while in situations lacking visual reference.
to a landing or to a point from which a landing may be
made visually. Inverter. A solid-state electronic device that converts D.C.
into A.C. current of the proper voltage and frequency to
Instrument flight rules (IFR). Rules and regulations operate A.C. gyro instruments.
established by the Federal Aviation Administration to govern
flight under conditions in which flight by outside visual Isobars. Lines which connect points of equal barometric
reference is not safe. IFR flight depends upon flying by pressure.
reference to instruments in the flight deck, and navigation is
accomplished by reference to electronic signals. Isogonic lines. Lines drawn across aeronautical charts to
connect points having the same magnetic variation.
Instrument landing system (ILS). An electronic system
that provides both horizontal and vertical guidance to a IVSI. See instantaneous vertical speed indicator.
specific runway, used to execute a precision instrument
approach procedure. Jet route. A route designated to serve flight operations from
18,000 feet MSL up to and including FL 450.
Instrument meteorological conditions (IMC).
Meteorological conditions expressed in terms of visibility, Jet stream. A high-velocity narrow stream of winds, usually
distance from clouds, and ceiling less than the minimums found near the upper limit of the troposphere, which flows
specified for visual meteorological conditions, requiring generally from west to east.
operations to be conducted under IFR.
Judgment. The mental process of recognizing and analyzing
Instrument takeoff. Using the instruments rather than all pertinent information in a particular situation, a rational
outside visual cues to maintain runway heading and execute evaluation of alternative actions in response to it, and a timely
a safe takeoff. decision on which action to take.

Intercooler. A device used to reduce the temperatures of the KIAS. Knots indicated airspeed.
compressed air before it enters the fuel metering device. The
resulting cooler air has a higher density, which permits the
engine to be operated with a higher power setting.

G-16

Kollsman window. A barometric scale window of a Leading-edge flap. A portion of the leading edge of an
sensitive altimeter used to adjust the altitude for the airplane wing that folds downward to increase the camber,
altimeter setting. lift, and drag of the wing. The leading-edge flaps are
extended for takeoffs and landings to increase the amount of
LAAS. See local area augmentation system. aerodynamic lift that is produced at any given airspeed.

Lag. The delay that occurs before an instrument needle attains Leans, the. A physical sensation caused by an abrupt
a stable indication. correction of a banked attitude entered too slowly to
stimulate the motion sensing system in the inner ear. The
Land breeze. A coastal breeze flowing from land to sea abrupt correction can create the illusion of banking in the
caused by temperature differences when the sea surface is opposite direction.
warmer than the adjacent land. The land breeze usually occurs
at night and alternates with the sea breeze that blows in the Licensed empty weight. The empty weight that consists
opposite direction by day. of the airframe, engine(s), unusable fuel, and undrainable
oil plus standard and optional equipment as specified in the
Land as soon as possible. Land without delay at the nearest equipment list. Some manufacturers used this term prior to
suitable area, such as an open field, at which a safe approach GAMA standardization.
and landing is assured.
Lift. A component of the total aerodynamic force on an airfoil
Land as soon as practical. The landing site and duration of and acts perpendicular to the relative wind.
flight are at the discretion of the pilot. Extended flight beyond
the nearest approved landing area is not recommended. Limit load factor. Amount of stress, or load factor, that an
aircraft can withstand before structural damage or failure
Land immediately. The urgency of the landing is paramount. occurs.
The primary consideration is to ensure the survival of the
occupants. Landing in trees, water, or other unsafe areas Lines of flux. Invisible lines of magnetic force passing
should be considered only as a last resort. between the poles of a magnet.

Lateral axis. An imaginary line passing through the center L/MF. See low or medium frequency.
of gravity of an airplane and extending across the airplane LMM. See locator middle marker.
from wingtip to wingtip.

Lateral stability (rolling). The stability about the Load factor. The ratio of a specified load to the total weight
longitudinal axis of an aircraft. Rolling stability or the ability of the aircraft. The specified load is expressed in terms of
of an airplane to return to level flight due to a disturbance any of the following: aerodynamic forces, inertial forces, or
that causes one of the wings to drop. ground or water reactions.

Latitude. Measurement north or south of the equator in Loadmeter. A type of ammeter installed between the generator
degrees, minutes, and seconds. Lines of latitude are also output and the main bus in an aircraft electrical system.
referred to as parallels.
LOC. See localizer.
LDA. See localizer-type directional aid.
Local area augmentation system (LAAS). A differential
Lead radial. The radial at which the turn from the DME arc global positioning system (DGPS) that improves the accuracy
to the inbound course is started. of the system by determining position error from the GPS
satellites, then transmitting the error, or corrective factors,
Leading edge. The part of an airfoil that meets the airflow to the airborne GPS receiver.
first.
Localizer (LOC). The portion of an ILS that gives left/right
Leading edge devices. High lift devices which are found guidance information down the centerline of the instrument
on the leading edge of the airfoil. The most common types runway for final approach.
are fixed slots, movable slats, and leading edge flaps.

G-17

Localizer-type directional aid (LDA). A NAVAID used Lubber line. The reference line used in a magnetic compass
for nonprecision instrument approaches with utility and or heading indicator.
accuracy comparable to a localizer but which is not a part
of a complete ILS and is not aligned with the runway. Some MAA. See maximum authorized altitude.
LDAs are equipped with a glideslope.
MAC. See mean aerodynamic chord.
Locator middle marker (LMM). Nondirectional radio
beacon (NDB) compass locator, collocated with a middle Mach number. The ratio of the true airspeed of the aircraft
marker (MM). to the speed of sound in the same atmospheric conditions,
named in honor of Ernst Mach, late 19th century physicist.
Locator outer marker (LOM). NDB compass locator,
collocated with an outer marker (OM). Mach meter. The instrument that displays the ratio of the
speed of sound to the true airspeed an aircraft is flying.
LOM. See locator outer marker.
Magnetic bearing (MB). The direction to or from a radio
Longitude. Measurement east or west of the Prime Meridian transmitting station measured relative to magnetic north.
in degrees, minutes, and seconds. The Prime Meridian is 0°
longitude and runs through Greenwich, England. Lines of Magnetic compass. A device for determining direction
longitude are also referred to as meridians. measured from magnetic north.

Longitudinal axis. An imaginary line through an aircraft Magnetic dip. A vertical attraction between a compass
from nose to tail, passing through its center of gravity. The needle and the magnetic poles. The closer the aircraft is to a
longitudinal axis is also called the roll axis of the aircraft. pole, the more severe the effect.
Movement of the ailerons rotates an airplane about its
longitudinal axis. Magnetic heading (MH). The direction an aircraft is pointed
with respect to magnetic north.
Longitudinal stability (pitching). Stability about the lateral
axis. A desirable characteristic of an airplane whereby it tends Magneto. A self-contained, engine-driven unit that supplies
to return to its trimmed angle of attack after displacement. electrical current to the spark plugs; completely independent
of the airplane’s electrical system. Normally there are two
Long range navigation (LORAN). An electronic magnetos per engine.
navigational system by which hyperbolic lines of position
are determined by measuring the difference in the time of Magnus effect. Lifting force produced when a rotating
reception of synchronized pulse signals from two fixed cylinder produces a pressure differential. This is the same
transmitters. LORAN-A operates in the 1750–1950 kHz effect that makes a baseball curve or a golf ball slice.
frequency band. LORAN-C and -D operate in the 100–110
kHz frequency band. Mandatory altitude. An altitude depicted on an instrument
approach chart with the altitude value both underscored and
LORAN. See long range navigation. overscored. Aircraft are required to maintain altitude at the
depicted value.
LORAN-C. A radio navigation system that utilizes master
and slave stations transmitting timed pulses. The time Mandatory block altitude. An altitude depicted on an
difference in reception of pulses from several stations instrument approach chart with two underscored and
establishes a hyperbolic line of position, which can be overscored altitude values between which aircraft are
identified on a LORAN chart. A fix in position is obtained required to maintain altitude.
by utilizing signals from two or more stations.
Maneuverability. Ability of an aircraft to change directions
Low or medium frequency. A frequency range between along a flightpath and withstand the stresses imposed upon
190 and 535 kHz with the medium frequency above 300 it.
kHz. Generally associated with nondirectional beacons
transmitting a continuous carrier with either a 400 or 1,020 Maneuvering speed (VA). The maximum speed at which full,
Hz modulation. abrupt control movement can be used without overstressing
the airframe.

G-18

Manifold absolute pressure. The absolute pressure of the Mean aerodynamic chord (MAC). The average distance
fuel/air mixture within the intake manifold, usually indicated from the leading edge to the trailing edge of the wing.
in inches of mercury.
Mean sea level. The average height of the surface of the
MAP. See missed approach point. sea at a particular location for all stages of the tide over a
19-year period.
Margin identification. The top and bottom areas on an
instrument approach chart that depict information about MEL. See minimum equipment list.
the procedure, including airport location and procedure
identification. Meridians. Lines of longitude.

Marker beacon. A low-powered transmitter that directs its Mesophere. A layer of the atmosphere directly above the
signal upward in a small, fan-shaped pattern. Used along the stratosphere.
flight path when approaching an airport for landing, marker
beacons indicate both aurally and visually when the aircraft METAR. See Aviation Routine Weather Report.
is directly over the facility.
MFD. See multi-function display.
Mass. The amount of matter in a body.
MH. See magnetic heading.
Maximum altitude. An altitude depicted on an instrument
approach chart with overscored altitude value at which or MHz. Megahertz.
below aircraft are required to maintain altitude.
Microburts. A strong downdraft which normally occurs over
Maximum authorized altitude (MAA). A published altitude horizontal distances of 1 NM or less and vertical distances of
representing the maximum usable altitude or flight level for less than 1,000 feet. In spite of its small horizontal scale, an
an airspace structure or route segment. intense microburst could induce windspeeds greater than 100
knots and downdrafts as strong as 6,000 feet per minute.
Maximum landing weight. The greatest weight that an
airplane normally is allowed to have at landing. Microwave landing system (MLS). A precision instrument
approach system operating in the microwave spectrum which
Maximum ramp weight. The total weight of a loaded normally consists of an azimuth station, elevation station,
aircraft, including all fuel. It is greater than the takeoff and precision distance measuring equipment.
weight due to the fuel that will be burned during the taxi
and runup operations. Ramp weight may also be referred to Mileage breakdown. A fix indicating a course change
as taxi weight. that appears on the chart as an “x” at a break between two
segments of a federal airway.
Maximum takeoff weight. The maximum allowable weight
for takeoff. Military operations area (MOA). Airspace established for
the purpose of separating certain military training activities
Maximum weight. The maximum authorized weight of from IFR traffic.
the aircraft and all of its equipment as specified in the Type
Certificate Data Sheets (TCDS) for the aircraft. Military training route (MTR). Airspace of defined vertical
and lateral dimensions established for the conduct of military
Maximum zero fuel weight (GAMA). The maximum training at airspeeds in excess of 250 knots indicated airspeed
weight, exclusive of usable fuel. (KIAS).

MB. See magnetic bearing. Minimum altitude. An altitude depicted on an instrument
MCA. See minimum crossing altitude. approach chart with the altitude value underscored. Aircraft are
required to maintain altitude at or above the depicted value.

MDA. See minimum descent altitude. Minimum crossing altitude (MCA). The lowest allowed
MEA. See minimum en route altitude. altitude at certain fixes an aircraft must cross when proceeding
in the direction of a higher minimum en route altitude
(MEA).

G-19

Minimum descent altitude (MDA). The lowest altitude (in MLS. See microwave landing system.
feet MSL) to which descent is authorized on final approach,
or during circle-to-land maneuvering in execution of a MM. Middle marker.
nonprecision approach.
MOA. See military operations area.
Minimum drag. The point on the total drag curve where
the lift-to-drag ratio is the greatest. At this speed, total drag MOCA. See minimum obstruction clearance altitude.
is minimized.
Mode C. Altitude reporting transponder mode.
Minimum en route altitude (MEA). The lowest published
altitude between radio fixes that ensures acceptable Moment. The product of the weight of an item multiplied
navigational signal coverage and meets obstacle clearance by its arm. Moments are expressed in pound-inches (lb-in).
requirements between those fixes. Total moment is the weight of the airplane multiplied by the
distance between the datum and the CG.
Minimum equipment list (MEL). A list developed for larger
aircraft that outlines equipment that can be inoperative for Moment arm. The distance from a datum to the applied
various types of flight including IFR and icing conditions. This force.
list is based on the master minimum equipment list (MMEL)
developed by the FAA and must be approved by the FAA for Moment index (or index). A moment divided by a constant
use. It is specific to an individual aircraft make and model. such as 100, 1,000, or 10,000. The purpose of using a moment
index is to simplify weight and balance computations of
Minimum obstruction clearance altitude (MOCA). The airplanes where heavy items and long arms result in large,
lowest published altitude in effect between radio fixes on VOR unmanageable numbers.
airways, off-airway routes, or route segments, which meets
obstacle clearance requirements for the entire route segment Monocoque. A shell-like fuselage design in which the
and which ensures acceptable navigational signal coverage stressed outer skin is used to support the majority of imposed
only within 25 statute (22 nautical) miles of a VOR. stresses. Monocoque fuselage design may include bulkheads
but not stringers.
Minimum reception altitude (MRA). The lowest altitude
at which an airway intersection can be determined. Monoplanes. Airplanes with a single set of wings.

Minimum safe altitude (MSA). The minimum altitude Movable slat. A movable auxiliary airfoil on the leading edge
depicted on approach charts which provides at least 1,000 feet of a wing. It is closed in normal flight but extends at high
of obstacle clearance for emergency use within a specified angles of attack. This allows air to continue flowing over the
distance from the listed navigation facility. top of the wing and delays airflow separation.

Minimum vectoring altitude (MVA). An IFR altitude lower MRA. See minimum reception altitude.
than the minimum en route altitude (MEA) that provides MSA. See minimum safe altitude.
terrain and obstacle clearance.

Minimums section. The area on an IAP chart that displays the MSL. See mean sea level.
lowest altitude and visibility requirements for the approach.
MTR. See military training route.
Missed approach. A maneuver conducted by a pilot when an
instrument approach cannot be completed to a landing. Multi-function display (MFD). Small screen (CRT or LCD)
in an aircraft that can be used to display information to the
Missed approach point (MAP). A point prescribed in each pilot in numerous configurable ways. Often an MFD will be
instrument approach at which a missed approach procedure used in concert with a primary flight display.
shall be executed if the required visual reference has not
been established. MVA. See minimum vectoring altitude.

Mixed ice. A mixture of clear ice and rime ice. N1. Rotational speed of the low pressure compressor in a
turbine engine.

G-20

N2. Rotational speed of the high pressure compressor in a Neutral static stability. The initial tendency of an aircraft
turbine engine. to remain in a new condition after its equilibrium has been
disturbed.
Nacelle. A streamlined enclosure on an aircraft in which
an engine is mounted. On multiengine propeller-driven NM. Nautical mile.
airplanes, the nacelle is normally mounted on the leading
edge of the wing. NOAA. National Oceanic and Atmospheric Administration.

NACG. See National Aeronautical Charting Group. No-gyro approach. A radar approach that may be used in
case of a malfunctioning gyro-compass or directional gyro.
NAS. See National Airspace System. Instead of providing the pilot with headings to be flown,
the controller observes the radar track and issues control
National Airspace System (NAS). The common network of instructions “turn right/left” or “stop turn,” as appropriate.
United States airspace—air navigation facilities, equipment
and services, airports or landing areas; aeronautical charts, Nondirectional radio beacon (NDB). A ground-based radio
information and services; rules, regulations and procedures, transmitter that transmits radio energy in all directions.
technical information; and manpower and material.
Nonprecision approach. A standard instrument approach
National Aeronautical Charting Group (NACG). A procedure in which only horizontal guidance is provided.
Federal agency operating under the FAA, responsible for
publishing charts such as the terminal procedures and en No procedure turn (NoPT). Term used with the appropriate
route charts. course and altitude to denote that the procedure turn is not
required.
National Route Program (NRP). A set of rules and
procedures designed to increase the flexibility of user flight NoPT. See no procedure turn.
planning within published guidelines.
NOTAM. See Notice to Airmen.
National Security Area (NSA). Areas consisting of airspace of
defined vertical and lateral dimensions established at locations Notice to Airmen (NOTAM). A notice filed with an aviation
where there is a requirement for increased security and safety authority to alert aircraft pilots of any hazards en route or at
of ground facilities. Pilots are requested to voluntarily avoid a specific location. The authority in turn provides means of
flying through the depicted NSA. When it is necessary to disseminating relevant NOTAMs to pilots.
provide a greater level of security and safety, flight in NSAs
may be temporarily prohibited. Regulatory prohibitions are NRP. See National Route Program.
disseminated via NOTAMs.
NSA. See National Security Area.
National Transportation Safety Board (NTSB). A United
States Government independent organization responsible for NTSB. See National Transportation Safety Board.
investigations of accidents involving aviation, highways,
waterways, pipelines, and railroads in the United States. NWS. National Weather Service.
NTSB is charged by congress to investigate every civil
aviation accident in the United States. Obstacle departure procedures (ODP). A preplanned
instrument flight rule (IFR) departure procedure printed for
NAVAID. Naviagtional aid. pilot use in textual or graphic form to provide obstruction
clearance via the least onerous route from the terminal area to
NAV/COM. Navigation and communication radio. the appropriate en route structure. ODPs are recommended
for obstruction clearance and may be flown without ATC
NDB. See nondirectional radio beacon. clearance unless an alternate departure procedure (SID or
radar vector) has been specifically assigned by ATC.
Negative static stability. The initial tendency of an aircraft
to continue away from the original state of equilibrium after Obstruction lights. Lights that can be found both on and off
being disturbed. an airport to identify obstructions.

G-21

Occluded front. A frontal occlusion occurs when a fast- Parallels. Lines of latitude.
moving cold front catches up with a slow moving warm front.
The difference in temperature within each frontal system is Parasite drag. Drag caused by the friction of air moving
a major factor in determining whether a cold or warm front over the aircraft structure; its amount varies directly with
occlusion occurs. the airspeed.

ODP. See obstacle departure procedures. Payload (GAMA). The weight of occupants, cargo, and
baggage.
OM. Outer marker.
Personality. The embodiment of personal traits and
Omission error. The failure to anticipate significant characteristics of an individual that are set at a very early
instrument indications following attitude changes; for age and extremely resistant to change.
example, concentrating on pitch control while forgetting
about heading or roll information, resulting in erratic control P-factor. A tendency for an aircraft to yaw to the left due to
of heading and bank. the descending propeller blade on the right producing more
thrust than the ascending blade on the left. This occurs when
Optical illusion. A misleading visual image. For the the aircraft’s longitudinal axis is in a climbing attitude in
purpose of this handbook, the term refers to the brain’s relation to the relative wind. The P-factor would be to the right
misinterpretation of features on the ground associated if the aircraft had a counterclockwise rotating propeller.
with landing, which causes a pilot to misread the spatial
relationships between the aircraft and the runway. PFD. See primary flight display.

Orientation. Awareness of the position of the aircraft and Phugoid oscillations. Long-period oscillations of an
of oneself in relation to a specific reference point. aircraft around its lateral axis. It is a slow change in pitch
accompanied by equally slow changes in airspeed. Angle
Otolith organ. An inner ear organ that detects linear of attack remains constant, and the pilot often corrects for
acceleration and gravity orientation. phugoid oscillations without even being aware of them.

Outer marker. A marker beacon at or near the glideslope PIC. See pilot in command.
intercept altitude of an ILS approach. It is normally located
four to seven miles from the runway threshold on the Pilotage. Navigation by visual reference to landmarks.
extended centerline of the runway.
Outside air temperature (OAT). The measured or indicated Pilot in command (PIC). The pilot responsible for the
air temperature (IAT) corrected for compression and friction operation and safety of an aircraft.
heating. Also referred to as true air temperature.
Pilot report (PIREP). Report of meteorological phenomena
Overcontrolling. Using more movement in the control encountered by aircraft.
column than is necessary to achieve the desired pitch-and-
bank condition. Pilot’s Operating Handbook/Airplane Flight Manual
(POH/AFM). FAA-approved documents published by the
Overboost. A condition in which a reciprocating engine has airframe manufacturer that list the operating conditions for
exceeded the maximum manifold pressure allowed by the a particular model of aircraft.
manufacturer. Can cause damage to engine components.
PIREP. See pilot report.
Overpower. To use more power than required for the purpose
of achieving a faster rate of airspeed change. Pitot pressure. Ram air pressure used to measure airspeed.

P-static. See precipitation static. Pitot-static head. A combination pickup used to sample pitot
PAPI. See precision approach path indicator. pressure and static air pressure.
PAR. See precision approach radar.
Plan view. The overhead view of an approach procedure on
an instrument approach chart. The plan view depicts the routes
that guide the pilot from the en route segments to the IAF.

G-22

Planform. The shape or form of a wing as viewed from Precision approach. A standard instrument approach

above. It may be long and tapered, short and rectangular, or procedure in which both vertical and horizontal guidance

various other shapes. is provided.

Pneumatic. Operation by the use of compressed air. Precision approach path indicator (PAPI). A system of
lights similar to the VASI, but consisting of one row of lights
POH/AFM. See Pilot’s Operating Handbook/Airplane in two- or four-light systems. A pilot on the correct glideslope
Flight Manual. will see two white lights and two red lights. See VASI.

Point-in-space approach. A type of helicopter instrument Precision approach radar (PAR). A type of radar used
approach procedure to a missed approach point more than at an airport to guide an aircraft through the final stages of
2,600 feet from an associated helicopter landing area. landing, providing horizontal and vertical guidance. The
radar operator directs the pilot to change heading or adjust
Poor judgment chain. A series of mistakes that may lead the descent rate to keep the aircraft on a path that allows it
to an accident or incident. Two basic principles generally to touch down at the correct spot on the runway.
associated with the creation of a poor judgment chain are:
(1) one bad decision often leads to another; and (2) as a Precision runway monitor (PRM). System allows
string of bad decisions grows, it reduces the number of simultaneous, independent instrument flight rules (IFR)
subsequent alternatives for continued safe flight. ADM is approaches at airports with closely spaced parallel runways.
intended to break the poor judgment chain before it can
cause an accident or incident. Preferred IFR routes. Routes established in the major
terminal and en route environments to increase system
Position error. Error in the indication of the altimeter, ASI, efficiency and capacity. IFR clearances are issued based on
and VSI caused by the air at the static system entrance not these routes, listed in the A/FD except when severe weather
being absolutely still. avoidance procedures or other factors dictate otherwise.

Position report. A report over a known location as Preignition. Ignition occurring in the cylinder before the
transmitted by an aircraft to ATC. time of normal ignition. Preignition is often caused by a
local hot spot in the combustion chamber igniting the fuel-
Positive static stability. The initial tendency to return to a air mixture.
state of equilibrium when disturbed from that state.
Pressure altitude. Altitude above the standard 29.92 "Hg
Power. Implies work rate or units of work per unit of time, plane.
and as such, it is a function of the speed at which the force is
developed. The term “power required” is generally associated Pressure demand oxygen system. A demand oxygen system
with reciprocating engines. that supplies 100 percent oxygen at sufficient pressure above
the altitude where normal breathing is adequate. Also referred
Powerplant. A complete engine and propeller combination to as a pressure breathing system.
with accessories.
Prevailing visibility. The greatest horizontal visibility
Precession. The characteristic of a gyroscope that causes an equaled or exceeded throughout at least half the horizon
applied force to be felt, not at the point of application, but circle (which is not necessarily continuous).
90° from that point in the direction of rotation.
Preventive maintenance. Simple or minor preservative
Precipitation. Any or all forms of water particles (rain, operations and the replacement of small standard parts
sleet, hail, or snow) that fall from the atmosphere and reach not involving complex assembly operation as listed in 14
the surface. CFR part 43, appendix A. Certificated pilots may perform
preventive maintenance on any aircraft that is owned or
Precipitation static (P-static). A form of radio interference operated by them provided that the aircraft is not used in air
caused by rain, snow, or dust particles hitting the antenna and carrier service.
inducing a small radio-frequency voltage into it.

G-23

Primary and supporting. A method of attitude instrument Radar services. Radar is a method whereby radio waves are
flying using the instrument that provides the most direct transmitted into the air and are then received when they have
indication of attitude and performance. been reflected by an object in the path of the beam. Range
is determined by measuring the time it takes (at the speed
Primary flight display (PFD). A display that provides of light) for the radio wave to go out to the object and then
increased situational awareness to the pilot by replacing the return to the receiving antenna. The direction of a detected
traditional six instruments used for instrument flight with object from a radar site is determined by the position of the
an easy-to-scan display that provides the horizon, airspeed, rotating antenna when the reflected portion of the radio wave
altitude, vertical speed, trend, trim, and rate of turn among is received.
other key relevant indications.
Radar summary chart. A weather product derived from the
PRM. See precision runway monitor. national radar network that graphically displays a summary
of radar weather reports.
Procedure turn. A maneuver prescribed when it is necessary
to reverse direction to establish an aircraft on the intermediate Radar weather report (SD). A report issued by radar
approach segment or final approach course. stations at 35 minutes after the hour, and special reports
as needed. Provides information on the type, intensity, and
Profile view. Side view of an IAP chart illustrating the vertical location of the echo tops of the precipitation.
approach path altitudes, headings, distances, and fixes.
Radials. The courses oriented from a station.
Prohibited area. Designated airspace within which flight of
aircraft is prohibited. Radio or radar altimeter. An electronic altimeter that
determines the height of an aircraft above the terrain by
Propeller. A device for propelling an aircraft that, measuring the time needed for a pulse of radio-frequency
when rotated, produces by its action on the air, a thrust energy to travel from the aircraft to the ground and return.
approximately perpendicular to its plane of rotation. It
includes the control components normally supplied by its Radio frequency (RF). A term that refers to alternating
manufacturer. current (AC) having characteristics such that, if the current is
input to antenna, an electromagnetic (EM) field is generated
Propeller/rotor modulation error. Certain propeller rpm suitable for wireless broadcasting and/or communications.
settings or helicopter rotor speeds can cause the VOR
course deviation indicator (CDI) to fluctuate as much as Radio magnetic indicator (RMI). An electronic navigation
±6°. Slight changes to the rpm setting will normally smooth instrument that combines a magnetic compass with an ADF
out this roughness. or VOR. The card of the RMI acts as a gyro-stabilized
magnetic compass, and shows the magnetic heading the
Rabbit, the. High-intensity flasher system installed at many aircraft is flying.
large airports. The flashers consist of a series of brilliant
blue-white bursts of light flashing in sequence along the Radiosonde. A weather instrument that observes and reports
approach lights, giving the effect of a ball of light traveling meteorological conditions from the upper atmosphere. This
toward the runway. instrument is typically carried into the atmosphere by some
form of weather balloon.
Radar. A system that uses electromagnetic waves to identify
the range, altitude, direction, or speed of both moving and Radio wave. An electromagnetic (EM ) wave with frequency
fixed objects such as aircraft, weather formations, and terrain. characteristics useful for radio transmission.
The term RADAR was coined in 1941 as an acronym for
Radio Detection and Ranging. The term has since entered RAIM. See receiver autonomous integrity monitoring.
the English language as a standard word, radar, losing the
capitalization in the process. RAM recovery. The increase in thrust as a result of ram air
pressures and density on the front of the engine caused by
Radar approach. The controller provides vectors while air velocity.
monitoring the progress of the flight with radar, guiding
the pilot through the descent to the airport/heliport or to a
specific runway.

G-24

Random RNAV routes. Direct routes, based on area REIL. See runway end identifier lights.
navigation capability, between waypoints defined in terms
of latitude/longitude coordinates, degree-distance fixes, or Relative bearing (RB). The angular difference between the
offsets from established routes/airways at a specified distance aircraft heading and the direction to the station, measured
and direction. clockwise from the nose of the aircraft.

Ranging signals. Transmitted from the GPS satellite, signals Relative bearing indicator (RBI). Also known as the fixed-
allowing the aircraft’s receiver to determine range (distance) card ADF, zero is always indicated at the top of the instrument
from each satellite. and the needle indicates the relative bearing to the station.

Rapid decompression. The almost instantaneous loss of Relative humidity. The ratio of the existing amount of
cabin pressure in aircraft with a pressurized cockpit or water vapor in the air at a given temperature to the maximum
cabin. amount that could exist at that temperature; usually expressed
in percent.
RB. See relative bearing.
Relative wind. Direction of the airflow produced by an object
RBI. See relative bearing indicator. moving through the air. The relative wind for an airplane in
flight flows in a direction parallel with and opposite to the
RCO. See remote communications outlet. direction of flight; therefore, the actual flight path of the
airplane determines the direction of the relative wind.
Receiver autonomous integrity monitoring (RAIM).
A system used to verify the usability of the received GPS Remote communications outlet (RCO). An unmanned
signals and warns the pilot of any malfunction in the communications facility that is remotely controlled by air
navigation system. This system is required for IFR-certified traffic personnel.
GPS units.
Required navigation performance (RNP). A specified level
Recommended altitude. An altitude depicted on an of accuracy defined by a lateral area of confined airspace in
instrument approach chart with the altitude value neither which an RNP-certified aircraft operates.
underscored nor overscored. The depicted value is an
advisory value. Restricted area. Airspace designated under 14 CFR part
73 within which the flight of aircraft, while not wholly
Receiver-transmitter (RT). A system that receives and prohibited, is subject to restriction.
transmits a signal and an indicator.
Reverse sensing. The VOR needle appearing to indicate the
Reduced vertical separation minimum (RVSM). Reduces reverse of normal operation.
the vertical separation between flight levels (FL) 290 and 410
from 2,000 feet to 1,000 feet, and makes six additional FLs RF. Radio frequency.
available for operation. Also see DRVSM.
Rhodopsin. The photosensitive pigments that initiate the
Reference circle (also, distance circle). The circle depicted visual response in the rods of the eye.
in the plan view of an IAP chart that typically has a 10 NM
radius, within which chart the elements are drawn to scale. Rigging. The final adjustment and alignment of an aircraft
and its flight control system that provides the proper
Regions of command. The “regions of normal and reversed aerodynamic characteristics.
command” refers to the relationship between speed and the
power required to maintain or change that speed in flight. Rigidity. The characteristic of a gyroscope that prevents its
axis of rotation tilting as the Earth rotates.
Region of reverse command. Flight regime in which flight
at a higher airspeed requires a lower power setting and a Rigidity in space. The principle that a wheel with a heavily
lower airspeed requires a higher power setting in order to weighted rim spinning rapidly will remain in a fixed position
maintain altitude. in the plane in which it is spinning.

G-25