PilotHandbook

Figure 12-27. Graphical METAR legend display.

Chapter Summary

While no weather forecast is guaranteed to be 100 percent
accurate, pilots have access to a myriad of weather
information on which to base flight decisions. Weather
products available for preflight planning to en route
information received over the radio or via satellite link
provide the pilot with the most accurate and up-to-date
information available. Each report provides a piece of the
weather puzzle. Pilots must use several reports to get an
overall picture and gain an understanding of the weather that
will affect the safe completion of a flight.

12-26

AirportChapter 13
Operations

Introduction

Each time a pilot operates an aircraft, the flight normally
begins and ends at an airport. An airport may be a small sod
field or a large complex utilized by air carriers. This chapter
examines airport operations, identifies features of an airport
complex, and provides information on operating on or in the
vicinity of an airport.

Types of Airports

There are two types of airports—towered and nontowered.
These types can be further subdivided to:

• Civil Airports—airports that are open to the general
public.

• Military/Federal Government airports—airports
operated by the military, National Aeronautics and
Space Administration (NASA), or other agencies of
the Federal Government.

• Private airports—airports designated for private or
restricted use only, not open to the general public.

13-1

Towered Airport operating control tower. The CTAF may be a Universal
A towered airport has an operating control tower. Air traffic Integrated Community (UNICOM), MULTICOM, Flight
control (ATC) is responsible for providing the safe, orderly, Service Station (FSS), or tower frequency and is identified
and expeditious flow of air traffic at airports where the in appropriate aeronautical publications. UNICOM is a
type of operations and/or volume of traffic requires such a nongovernment air/ground radio communication station
service. Pilots operating from a towered airport are required which may provide airport information at public use airports
to maintain two-way radio communication with air traffic where there is no tower or FSS. On pilot request, UNICOM
controllers, and to acknowledge and comply with their stations may provide pilots with weather information, wind
instructions. Pilots must advise ATC if they cannot comply direction, the recommended runway, or other necessary
with the instructions issued and request amended instructions. information. If the UNICOM frequency is designated as
A pilot may deviate from an air traffic instruction in an the CTAF, it will be identified in appropriate aeronautical
emergency, but must advise ATC of the deviation as soon publications. Figure 13-1 lists recommended communication
as possible. procedures. More information on radio communications is
discussed later in this chapter.
Nontowered Airport
An nontowered airport does not have an operating control Sources for Airport Data
tower. Two-way radio communications are not required,
although it is a good operating practice for pilots to transmit When a pilot flies into a different airport, it is important to
their intentions on the specified frequency for the benefit review the current data for that airport. This data provides the
of other traffic in the area. The key to communicating at pilot with information, such as communication frequencies,
an airport without an operating control tower is selection services available, closed runways, or airport construction.
of the correct common frequency. The acronym CTAF, Three common sources of information are:
which stands for Common Traffic Advisory Frequency,
is synonymous with this program. A CTAF is a frequency • Aeronautical Charts
designated for the purpose of carrying out airport advisory
practices while operating to or from an airport without an • Airport/Facility Directory (A/FD)

• Notices to Airmen (NOTAMs)

Cummunication/Broadcast Procedures

Facility at Airport Frequency Use Practice Instrument
Approach
Outbound Inbound
UNICOM Communicate with UNICOM
(no tower or FSS) station on published CTAF Before taxiing and 10 miles out.
frequency (122.7, 122.8, 122.725, before taxiing on the Entering downwind,
No tower, FSS, 122.975, or 123.0). If unable to runway for departure. base, and final.
or UNICOM contact UNICOM station, use self- Leaving the runway.
announce procedures on CTAF.
Before taxiing and 10 miles out. Departing final
Self-announce on MULTICOM before taxiing on the Entering downwind, approach fix (name)
frequency 122.9. runway for departure. base, and final. or on final approach
Leaving the runway. segment inbound.
No tower in Communicate with FSS on CTAF Before taxiing and
before taxiing on the 10 miles out. Approach
operation, FSS open frequency. runway for departure. Entering downwind, completed/terminated.
base, and final.
FSS closed Self-announce on CTAF. Before taxiing and Leaving the runway.
(no tower) before taxiing on the
runway for departure. 10 miles out.
Tower or FSS Self-announce on CTAF. Entering downwind,
not in operation Before taxiing and base, and final.
before taxiing on the Leaving the runway.
runway for departure.
10 miles out.
Entering downwind,
base, and final.
Leaving the runway.

Figure 13-1. Recommended communication procedures.

13-2

Aeronautical Charts routing, visual flight rules (VFR) waypoints, a listing of very
Aeronautical charts provide specific information on airports. high frequency (VHF) omnidirectional range (VOR) receiver
Chapter 15, Navigation, contains an excerpt from an checkpoints, aeronautical chart bulletins, land and hold short
aeronautical chart and an aeronautical chart legend, which operations (LAHSO) for selected airports, airport diagrams
provides guidance on interpreting the information on the for selected towered airports, en route flight advisory
chart. service (EFAS) outlets, parachute jumping areas, and facility
telephone numbers. It would be helpful to review an A/FD to
Airport/Facility Directory (A/FD) become familiar with the information it contains.
The A/FD provides the most comprehensive information on
a given airport. It contains information on airports, heliports, Notices to Airmen (NOTAMs)
and seaplane bases that are open to the public. The A/FD is NOTAMs provide the most current information available.
published in seven books, which are organized by regions and They provide time-critical information on airports and
are revised every 56 days. The A/FD is also available digitally changes that affect the national airspace system (NAS) and
at www.naco.faa.gov. Figure 13-2 contains an excerpt from are of concern to IFR operations. NOTAM information is
a directory. For a complete listing of information provided classified into three categories. These are NOTAM-D or
in an A/FD and how the information may be decoded, refer distant, NOTAM-L or local, and flight data center (FDC)
to the “Directory Legend Sample” located in the front of NOTAMs. NOTAM-Ds are attached to hourly weather
each A/FD. reports and are available at automated flight service stations
(AFSS) or FSS.
In addition to airport information, each A/FD contains
information such as special notices, Federal Aviation FDC NOTAMs are issued by the National Flight Data Center
Administration (FAA) and National Weather Service (NWS) and contain regulatory information, such as temporary
telephone numbers, preferred instrument flight rules (IFR) flight restrictions or an amendment to instrument approach

Figure 13-2. Airport/Facility Directory excerpt.

13-3

procedures. The NOTAM-Ds and FDC NOTAMs are Airport Markings and Signs
contained in the NOTAM publication, which is issued every
28 days. Prior to any flight, pilots should check for any There are markings and signs used at airports, which provide
NOTAMs that could affect their intended flight. directions and assist pilots in airport operations. Some of the
most common markings and signs are discussed. Additional
NOTAM-D information includes such data as taxiway information may be found in Chapter 2, Aeronautical
closures, personnel and equipment near or crossing runways, Lighting and Other Airport Visual Aids, in the Aeronautical
and airport lighting aids that do not affect instrument Information Manual (AIM).
approach criteria, such as visual approach slope indicator
(VASI). NOTAM-D information is distributed locally only Runway Markings
and is not attached to the hourly weather reports. A separate Runway markings vary depending on the type of operations
file of local NOTAMs is maintained at each FSS for facilities conducted at the airport. Figure 13-3 shows a runway that
in their area only. NOTAM-D information for other FSS areas is approved as a precision instrument approach runway and
must be specifically requested directly from the FSS that has some other common runway markings. A basic VFR runway
responsibility for the airport concerned. may only have centerline markings and runway numbers.

Surface Painted LEGEND
Runway Marking In-Pavement Runway Guard Lights
Elevated Runway Guard Lights
19 Stop Bar
Centerline/Lead-On Lights
Clearance Bar Lights

4 Position Marking

Stop Bar/ILS Hold Vehicle Lanes
(Zipper Style)

Terminal
Non-Movement Area

A

Hold Marking for A Taxiway Edge Marking (Do Not Cross)
Land and Hold 4 Taxiway/Taxiway Hold Marking
Short Operations

Figure 13-3. Selected airport markings and surface lighting.
13-4

Since aircraft are affected by the wind during takeoffs intended to be used by an aircraft. If it is a dashed marking,
and landings, runways are laid out according to the local an aircraft may use that portion of the pavement. Where a
prevailing winds. Runway numbers are in reference to taxiway approaches a runway, there may be a holding position
magnetic north. Certain airports have two or even three marker. These consist of four yellow lines (two solid and two
runways laid out in the same direction. These are referred to dashed). The solid lines are where the aircraft is to hold. At
as parallel runways and are distinguished by a letter added some towered airports, holding position markings may be
to the runway number (e.g., runway 36L (left), 36C (center), found on a runway. They are used when there are intersecting
and 36R (right)). runways, and ATC issues instructions such as “cleared to
land—hold short of runway 30.”
Another feature of some runways is a displaced threshold. A
threshold may be displaced because of an obstruction near Other Markings
the end of the runway. Although this portion of the runway Some other markings found on the airport include vehicle
is not to be used for landing, it may be available for taxiing, roadway markings, VOR receiver checkpoint markings, and
takeoff, or landing rollout. Some airports may have a blast non-movement area boundary markings.
pad/stopway area. The blast pad is an area where a propeller
or jet blast can dissipate without creating a hazard. The Vehicle roadway markings are used when necessary to define
stopway area is paved in order to provide space for an aircraft a pathway for vehicle crossing areas that are also intended
to decelerate and stop in the event of an aborted takeoff. These for aircraft. These markings usually consist of a solid white
areas cannot be used for takeoff or landing. line to delineate each edge of the roadway and a dashed line
to separate lanes within the edges of the roadway. In lieu of
Taxiway Markings the solid lines, zipper markings may be used to delineate the
Aircraft use taxiways to transition from parking areas to the edges of the vehicle roadway. [Figure 13-4]
runway. Taxiways are identified by a continuous yellow
centerline stripe and may include edge markings to define the A VOR receiver checkpoint marking consists of a painted
edge of the taxiway. This is usually done when the taxiway circle with an arrow in the middle. The arrow is aligned in
edge does not correspond with the edge of the pavement. If an the direction of the checkpoint azimuth. This allows pilots to
edge marking is a continuous line, the paved shoulder is not check aircraft instruments with navigational aid signals.

Roadway edge stripes, Roadway lane line
white, continuous 6" white 6" (15 cm)
(15 cm) wide wide dashes 15'
(4.5 m) long with
Roadway stop line, spaces between
white, 2' (0.67 m) wide, dashes 25' (7.5 m)
across the approach long
lane (see text for
additional requirements)

Not to scale Taxiway centerline marking Roadway edge
Taxiway edge marking (dashed) stripes (see text)
white, zipper style
Figure 13-4. Vehicle roadway markings.
13-5

A non-movement area boundary marking delineates a runways, terminals, cargo areas, and civil aviation

movement area under ATC. These markings are yellow and areas.

located on the boundary between the movement and non- • Information signs—yellow background with black
movement area. They normally consist of two yellow lines inscription. These signs are used to provide the pilot
(one solid and one dashed). with information on such things as areas that cannot

Airport Signs be seen from the control tower, applicable radio
There are six types of signs that may be found at airports. The frequencies, and noise abatement procedures. The
more complex the layout of an airport, the more important airport operator determines the need, size, and location
the signs become to pilots. Figure 13-5 shows examples of of these signs.
signs, their purpose, and appropriate pilot action. The six
types of signs are: • Runway distance remaining signs—black background
with white numbers. The numbers indicate the distance
• Mandatory instruction signs—red background with of the remaining runway in thousands of feet.
white inscription. These signs denote an entrance to a
runway, critical area, or prohibited area. Airport Lighting

• Location signs—black with yellow inscription and a The majority of airports have some type of lighting for night
yellow border, no arrows. They are used to identify a operations. The variety and type of lighting systems depends
taxiway or runway location, to identify the boundary on the volume and complexity of operations at a given airport.
of the runway, or identify an instrument landing Airport lighting is standardized so that airports use the same
system (ILS) critical area. light colors for runways and taxiways.

• Direction signs—yellow background with black Airport Beacon

inscription. The inscription identifies the designation Airport beacons help a pilot identify an airport at night.

of the intersecting taxiway(s) leading out of an The beacons are operated from dusk till dawn. Sometimes

intersection. they are turned on if the ceiling is less than 1,000 feet and/

• Destination signs—yellow background with black or the ground visibility is less than 3 statute miles (VFR
inscription and also contain arrows. These signs minimums). However, there is no requirement for this, so
provide information on locating things, such as a pilot has the responsibility of determining if the weather
meets VFR requirements. The beacon has a vertical light

Airport Sign Systems

Type of Sign Action or Purpose Type of Sign Action or Purpose
Taxiway/Runway Hold Position: Runway Safety Area/Obstacle Free
4-22 Hold short of runway on taxiway J Zone Boundary:
26-8 Runway/Runway Hold Position: L Exit boundary of runway protected areas
Hold short of intersecting runway ILS Critical Area Boundary:
8-APCH Runway Approach Hold Position: 22 Exit boundary of ILS critical area
Hold short of aircraft on approach Taxiway Direction:
ILS ILS Critical Area Hold Position: MIL Defines direction & designation of
Hold short of ILS approach critical area intersecting taxiway(s)
B No Entry: Runway Exit:
Identifies paved areas where aircraft entry is Defines direction & designation of exit
prohibited taxiway from runway
Taxiway Location: Outbound Destination:
Identifies taxiway on which aircraft is located Defines directions to takeoff runways

Inbound Destination:
Defines directions for arriving aircraft

22 Runway Location: AGL Taxiway Ending Marker:
Identifies runway on which aircraft is located Indicates taxiway does not continue
4 Runway Distance Remaining: Direction Sign Array:
Provides remaining runway length in 1,000 Identifies location in conjunction with
feet increments multiple intersecting taxiways

Figure 13-5. Airport signs.

13-6

distribution to make it most effective from 1–10° above the The VASI consists of light units arranged in bars. There are
horizon, although it can be seen well above or below this 2-bar and 3-bar VASIs. The 2-bar VASI has near and far
spread. The beacon may be an omnidirectional capacitor- light bars and the 3-bar VASI has near, middle, and far light
discharge device, or it may rotate at a constant speed, which bars. Two-bar VASI installations provide one visual glidepath
produces the visual effect of flashes at regular intervals. The which is normally set at 3°. The 3-bar system provides two
combination of light colors from an airport beacon indicates glidepaths, the lower glidepath normally set at 3° and the
the type of airport. [Figure 13-6] Some of the most common upper glidepath ¼ degree above the lower glidepath.
beacons are:
The basic principle of the VASI is that of color differentiation
• Flashing white and green for civilian land airports; between red and white. Each light unit projects a beam of
light, a white segment in the upper part of the beam and a
• Flashing white and yellow for a water airport; red segment in the lower part of the beam. The lights are
arranged so the pilot sees the combination of lights shown in
• Flashing white, yellow, and green for a heliport; and Figure 13-7 to indicate below, on, or above the glidepath.

• Two quick white flashes alternating with a green flash
identifying a military airport.

Below Glidepath On Glidepath Above Glidepath

White Green White Yellow Far Bar Far Bar Far Bar
Near Bar Near Bar Near Bar

Figure 13-6. Airport rotating beacons. Figure 13-7. Two-bar VASI system.

Approach Light Systems Other Glidepath Systems
Approach light systems are primarily intended to provide a A precision approach path indicator (PAPI) uses lights similar
means to transition from instrument flight to visual flight for to the VASI system except they are installed in a single row,
landing. The system configuration depends on whether the normally on the left side of the runway. [Figure 13-8]
runway is a precision or nonprecision instrument runway.
Some systems include sequenced flashing lights, which A tri-color system consists of a single light unit projecting
appear to the pilot as a ball of light traveling toward the a three-color visual approach path. Below the glidepath is
runway at high speed. Approach lights can also aid pilots indicated by red, on the glidepath is indicated by green, and
operating under VFR at night. above the glidepath is indicated by amber. When descending
below the glidepath, there is a small area of dark amber. Pilots
Visual Glideslope Indicators should not mistake this area for an “above the glidepath”
Visual glideslope indicators provide the pilot with glidepath indication. [Figure 13-9]
information that can be used for day or night approaches. By
maintaining the proper glidepath as provided by the system, Pulsating visual approach slope indicators normally consist of
a pilot should have adequate obstacle clearance and should a single light unit projecting a two-color visual approach path
touch down within a specified portion of the runway. into the final approach area of the runway upon which the
indicator is installed. The on glidepath indication is a steady
Visual Approach Slope Indicator (VASI) white light. The slightly below glidepath indication is a steady
VASI installations are the most common visual glidepath red light. If the aircraft descends further below the glidepath,
systems in use. The VASI provides obstruction clearance the red light starts to pulsate. The above glidepath indication
within 10° of the runway extended runway centerline, and to is a pulsating white light. The pulsating rate increases as the
four nautical miles (NM) from the runway threshold. aircraft gets further above or below the desired glideslope.

13-7

High Slightly High On Glidepath Slightly Low Low
more than 3.5° 3.2° 3° 2.8° less than 2.5°

Figure 13-8. Precision approach path indicator.

Above glidepath AGmrebeenr Amber
On glidepath Red

Below glidepath

Figure 13-9. Tri-color visual approach slope indicator.

The useful range of the system is about four miles during the of a pair of synchronized flashing lights located laterally
day and up to ten miles at night. [Figure 13-10] on each side of the runway threshold. REILs may be either
omnidirectional or unidirectional facing the approach area.
Runway Lighting
There are various lights that identify parts of the runway Runway Edge Lights
complex. These assist a pilot in safely making a takeoff or Runway edge lights are used to outline the edges of runways
landing during night operations. at night or during low visibility conditions. These lights
are classified according to the intensity they are capable of
Runway End Identifier Lights (REIL) producing: high intensity runway lights (HIRL), medium
Runway end identifier lights (REIL) are installed at many intensity runway lights (MIRL), and low intensity runway
airfields to provide rapid and positive identification of the lights (LIRL). The HIRL and MIRL have variable intensity
approach end of a particular runway. The system consists settings. These lights are white, except on instrument runways

Above glidepath Puwlshaitteing
PuSltseSwaathtediinaytedgryerded
On glidepath
Slightly below glidepath

Below glidepath

Threshold

Figure 13-10. Pulsating visual approach slope indicator.
13-8

where amber lights are used on the last 2,000 feet or half the Control of Airport Lighting
length of the runway, whichever is less. The lights marking Airport lighting is controlled by air traffic controllers at
the end of the runway are red. towered airports. At nontowered airports, the lights may
be on a timer, or where an FSS is located at an airport, the
In-Runway Lighting FSS personnel may control the lighting. A pilot may request
Runway centerline lighting system (RCLS)—installed on various light systems be turned on or off and also request a
some precision approach runways to facilitate landing under specified intensity, if available, from ATC or FSS personnel.
adverse visibility conditions. They are located along the At selected nontowered airports, the pilot may control the
runway centerline and are spaced at 50-foot intervals. When lighting by using the radio. This is done by selecting a
viewed from the landing threshold, the runway centerline specified frequency and clicking the radio microphone. For
lights are white until the last 3,000 feet of the runway. The information on pilot controlled lighting at various airports,
white lights begin to alternate with red for the next 2,000 feet. refer to the A/FD. [Figure 13-11]
For the remaining 1,000 feet of the runway, all centerline
lights are red. Key Mike Function

Touchdown zone lights (TDZL)—installed on some precision 7 times within 5 seconds Highest intensity available
approach runways to indicate the touchdown zone when 5 times within 5 seconds
landing under adverse visibility conditions. They consist of 3 times within 5 seconds Medium or lower intensity
two rows of transverse light bars disposed symmetrically (Lower REIL or REIL off)
about the runway centerline. The system consists of steady- Lowest intensity available
burning white lights which start 100 feet beyond the landing (Lower REIL or REIL off)
threshold and extend to 3,000 feet beyond the landing
threshold or to the midpoint of the runway, whichever is Figure 13-11. Radio controlled runway lighting.
less.
Taxiway Lights
Taxiway centerline lead-off lights—provide visual guidance Omnidirectional taxiway lights outline the edges of the
to persons exiting the runway. They are color-coded to warn taxiway and are blue in color. At many airports, these edge
pilots and vehicle drivers that they are within the runway lights may have variable intensity settings that may be
environment or ILS/MLS critical area, whichever is more adjusted by an air traffic controller when deemed necessary
restrictive. Alternate green and yellow lights are installed, or when requested by the pilot. Some airports also have
beginning with green, from the runway centerline to one taxiway centerline lights that are green in color.
centerline light position beyond the runway holding position
or ILS/MLS critical area holding position. Obstruction Lights
Obstructions are marked or lighted to warn pilots of
Taxiway centerline lead-on lights—provide visual guidance their presence during daytime and nighttime conditions.
to persons entering the runway. These “lead-on” lights Obstruction lighting can be found both on and off an airport
are also color-coded with the same color pattern as lead- to identify obstructions. They may be marked or lighted in
off lights to warn pilots and vehicle drivers that they are any of the following conditions.
within the runway environment or instrument landing
system/microwave landing system (ILS/MLS) critical area, • Red obstruction lights—flash or emit a steady red color
whichever is more conservative. The fixtures used for lead-on during nighttime operations, and the obstructions are
lights are bidirectional (i.e., one side emits light for the lead- painted orange and white for daytime operations.
on function while the other side emits light for the lead-off
function). Any fixture that emits yellow light for the lead-off • High intensity white obstruction lights—flash high
function also emits yellow light for the lead-on function. intensity white lights during the daytime with the
intensity reduced for nighttime.
Land and hold short lights—used to indicate the hold short
point on certain runways which are approved for LAHSO. • Dual lighting—a combination of flashing red beacons
Land and hold short lights consist of a row of pulsing white and steady red lights for nighttime operation, and high
lights installed across the runway at the hold short point. intensity white lights for daytime operations.
Where installed, the lights are on anytime LAHSO is in effect.
These lights are off when LAHSO is not in effect.

13-9

Wind Direction Indicators Traffic Patterns

It is important for a pilot to know the direction of the wind. At those airports without an operating control tower, a
At facilities with an operating control tower, this information segmented circle visual indicator system [Figure 13-13], if
is provided by ATC. Information may also be provided by installed, is designed to provide traffic pattern information.
FSS personnel located at a particular airport or by requesting Usually located in a position affording maximum visibility
information on a CTAF at airports that have the capacity to to pilots in the air and on the ground and providing a
receive and broadcast on this frequency. centralized location for other elements of the system, the
segmented circle consists of the following components: wind
When none of these services is available, it is possible to direction indicators, landing direction indicators, landing strip
determine wind direction and runway in use by visual wind indicators, and traffic pattern indicators.
indicators. A pilot should check these wind indicators even
when information is provided on the CTAF at a given airport A tetrahedron is installed to indicate the direction of landings
because there is no assurance that the information provided and takeoffs when conditions at the airport warrant its use.
is accurate. It may be located at the center of a segmented circle and
may be lighted for night operations. The small end of the
The wind direction indicator can be a wind cone, wind sock, tetrahedron points in the direction of landing. Pilots are
tetrahedron, or wind tee. These are usually located in a central cautioned against using a tetrahedron for any purpose other
location near the runway and may be placed in the center than as an indicator of landing direction. At airports with
of a segmented circle, which identifies the traffic pattern control towers, the tetrahedron should only be referenced
direction, if it is other than the standard left-hand pattern. when the control tower is not in operation. Tower instructions
[Figures 13-12 and 13-13] supersede tetrahedron indications.

The wind sock is a good source of information since it not Landing strip indicators are installed in pairs as shown in
only indicates wind direction, but allows the pilot to estimate Figure 13-13 and are used to show the alignment of landing
the wind velocity and gusts or factor. The wind sock extends strips. Traffic pattern indicators are arranged in pairs in
out straighter in strong winds and tends to move back and conjunction with landing strip indicators and used to indicate
forth when the wind is gusty. Wind tees and tetrahedrons can the direction of turns when there is a variation from the
swing freely, and align themselves with the wind direction. normal left traffic pattern. (If there is no segmented circle
The wind tee and tetrahedron can also be manually set to installed at the airport, traffic pattern indicators may be
align with the runway in use; therefore, a pilot should also installed on or near the end of the runway.)
look at the wind sock, if available.

Tetrahedron

WIND

Wind Tee

Wind Sock or Cone

Figure 13-12. Wind direction indicators.
13-10

Traffic Pattern 5. If remaining in the traffic pattern, commence turn to
Indicators crosswind leg beyond the departure end of the runway
within 300 feet of pattern altitude.
Landing Direction
Indicator 6. If departing the traffic pattern, continue straight out,
or exit with a 45° turn (to the left when in a left-hand
traffic pattern; to the right when in a right-hand traffic
pattern) beyond the departure end of the runway, after
reaching pattern altitude. [Figure 13-14]

Landing Runway Wind Cone Example: Key to Traffic Pattern Operations—
or Landing Strip Parallel Runways

Indicators 1. Enter pattern in level flight, abeam the midpoint
of the runway, at pattern altitude. (1,000' AGL is
Figure 13-13. Segmented circle. recommended pattern altitude unless established
otherwise.)
At most airports and military air bases, traffic pattern altitudes
for propeller-driven aircraft generally extend from 600 feet 2. Maintain pattern altitude until abeam approach end of
to as high as 1,500 feet above ground level (AGL). Pilots can the landing runway on downwind leg.
obtain the traffic pattern altitude for an airport from the A/FD.
Also, traffic pattern altitudes for military turbojet aircraft 3. Complete turn to final at least ¼ mile from the
sometimes extend up to 2,500 feet AGL. Therefore, pilots runway.
of en route aircraft should be constantly on the alert for other
aircraft in traffic patterns and avoid these areas whenever 4. Continue straight ahead until beyond departure end
possible. When operating at an airport, traffic pattern of runway.
altitudes should be maintained unless otherwise required
by the applicable distance from cloud criteria in Title 14 of 5. If remaining in the traffic pattern, commence turn to
the Code of Federal Regulations (14 CFR) section 91.155. crosswind leg beyond the departure end of the runway
Additional information on airport traffic pattern operations within 300 feet of pattern altitude.
can be found in Chapter 4, Air Traffic Control, of the AIM.
Pilots can find traffic pattern information and restrictions 6. If departing the traffic pattern, continue straight out,
such as noise abatement in the A/FD. or exit with a 45° turn (to the left when in a left-hand
traffic pattern; to the right when in a right-hand traffic
Example: Key to Traffic Pattern Operations— pattern) beyond the departure end of the runway, after
Single Runway reaching pattern altitude.

1. Enter pattern in level flight, abeam the midpoint 7. Do not overshoot final or continue on a track which
of the runway, at pattern altitude. (1,000' AGL) is penetrates the final approach of the parallel runway.
recommended pattern altitude unless established
otherwise.) 8. Do not continue on a track which penetrates the departure
path of the parallel runway. [Figure 13-15]
2. Maintain pattern altitude until abeam approach end of
the landing runway on downwind leg. Radio Communications

3. Complete turn to final at least ¼ mile from the Operating in and out of a towered airport, as well as in a
runway. good portion of the airspace system, requires that an aircraft
have two-way radio communication capability. For this
4. Continue straight ahead until beyond departure end reason, a pilot should be knowledgeable of radio station
of runway. license requirements and radio communications equipment
and procedures.

Radio License
There is no license requirement for a pilot operating in the
United States; however, a pilot who operates internationally
is required to hold a restricted radiotelephone permit issued
by the Federal Communications Commission (FCC). There

13-11

Application of Traffic LEGEND
Pattern Indicators
Entry
Recommended Standard Left-Hand Traffic
pattern (depicted)
(Standard right-hand traffic pattern would be mirror image)

Downwind Departure
Segmented Circle
Base
Crosswind

Final Departure Departure
Hazard or Populated Area Traffic Pattern Indicators
RUNWAY

Landing Direction Indicator Wind Cone
Landing Runway

(or Landing Strip Indicators)

Figure 13-14. Traffic pattern operations—single runway.

is also no station license requirement for most general the capability of transmitting and receiving on the 8.33 kHz
aviation aircraft operating in the United States. A station spaced channels.
license is required however for an aircraft which is operating
internationally, which uses other than a VHF radio, and which Using proper radio phraseology and procedures contribute to
meets other criteria. a pilot’s ability to operate safely and efficiently in the airspace
system. A review of the Pilot/Controller Glossary contained
Radio Equipment in the AIM assists a pilot in the use and understanding of
In general aviation, the most common types of radios are standard terminology. The AIM also contains many examples
VHF. A VHF radio operates on frequencies between 118.0 of radio communications.
and 136.975 and is classified as 720 or 760 depending
on the number of channels it can accommodate. The 720 ICAO has adopted a phonetic alphabet, which should be
and 760 use .025 spacing (118.025, 118.050) with the 720 used in radio communications. When communicating with
having a frequency range up to 135.975 and the 760 going ATC, pilots should use this alphabet to identify their aircraft.
up to 136.975. VHF radios are limited to line of sight [Figure 13-16]
transmissions; therefore, aircraft at higher altitudes are able
to transmit and receive at greater distances. Lost Communication Procedures
It is possible that a pilot might experience a malfunction of
In March of 1997, the International Civil Aviation the radio. This might cause the transmitter, receiver, or both
Organization (ICAO) amended its International Standards to become inoperative. If a receiver becomes inoperative and
and Recommended Practices to incorporate a channel plan a pilot needs to land at a towered airport, it is advisable to
specifying 8.33 kHz channel spacings in the Aeronautical remain outside or above Class D airspace until the direction
Mobile Service. The 8.33 kHz channel plan was adopted to and flow of traffic is determined. A pilot should then advise
alleviate the shortage of VHF ATC channels experienced in the tower of the aircraft type, position, altitude, and intention
western Europe and in the United Kingdom. Seven western to land. The pilot should continue, enter the pattern, report a
European countries and the United Kingdom implemented position as appropriate, and watch for light signals from the
the 8.33 kHz channel plan on January 1, 1999. Accordingly, tower. Light signal colors and their meanings are contained
aircraft operating in the airspace of these countries must have in Figure 13-17.

13-12

LEGEND
Standard Left-Hand
Traffic Pattern (depicted)
Right-HandTraffic
Pattern (depicted)

Base Crosswind

Final Departure No Transgression Zone
No Transgression Zone Segmented Circle
Traffic Pattern
Final Departure Indicators

Base Landing DirectionCrosswind
Indicator

Downwind

Entry Landing Runway
(or Landing Strip Indicators)
Wind Cone

Figure 13-15. Traffic pattern operation—parallel runways. Air Traffic Control (ATC) Services

If the transmitter becomes inoperative, a pilot should Besides the services provided by an FSS as discussed in
follow the previously stated procedures and also monitor Chapter 12, Aviation Weather Services, numerous other
the appropriate ATC frequency. During daylight hours ATC services are provided by ATC. In many instances a pilot
transmissions may be acknowledged by rocking the wings, is required to have contact with ATC, but even when not
and at night by blinking the landing light. required, a pilot finds it helpful to request their services.

When both receiver and transmitter are inoperative, the pilot Primary Radar
should remain outside of Class D airspace until the flow of Radar is a device which provides information on range,
traffic has been determined and then enter the pattern and azimuth, and/or elevation of objects in the path of the
watch for light signals. transmitted pulses. It measures the time interval between
transmission and reception of radio pulses and correlates the
If a radio malfunctions prior to departure, it is advisable to angular orientation of the radiated antenna beam or beams in
have it repaired, if possible. If this is not possible, a call should azimuth and/or elevation. Range is determined by measuring
be made to ATC and the pilot should request authorization the time it takes for the radio wave to go out to the object
to depart without two-way radio communications. If and then return to the receiving antenna. The direction of a
authorization is given to depart, the pilot is advised to monitor detected object from a radar site is determined by the position
the appropriate frequency and/or watch for light signals as
appropriate.

13-13

Character Morse Code Telephony Phonic Pronunciation services and prevent a controller from issuing advisories
concerning aircraft which are not under his or her control
A and cannot be seen on radar.
B
C The characteristics of radio waves are such that they normally
D travel in a continuous straight line unless they are “bent” by
E atmospheric phenomena such as temperature inversions,
F reflected or attenuated by dense objects such as heavy clouds
and precipitation, or screened by high terrain features.
G
H ATC Radar Beacon System (ATCRBS)
I The ATC radar beacon system (ATCRBS) is often referred
J to as “secondary surveillance radar.” This system consists
K of three components and helps in alleviating some of
L the limitations associated with primary radar. The three
M components are an interrogator, transponder, and radarscope.
N The advantages of ATCRBS are the reinforcement of radar
O targets, rapid target identification, and a unique display of
P selected codes.
Q
R Transponder
S The transponder is the airborne portion of the secondary
surveillance radar system and a system with which a
T pilot should be familiar. The ATCRBS cannot display the
U secondary information unless an aircraft is equipped with
V a transponder. A transponder is also required to operate
W in certain controlled airspace as discussed in Chapter 14,
X Airspace.
Y
Z A transponder code consists of four numbers from 0 to 7
1 (4,096 possible codes). There are some standard codes, or
2 ATC may issue a four-digit code to an aircraft. When a
3 controller requests a code or function on the transponder, the
4 word “squawk” may be used. Figure 13-18 lists some standard
5 transponder phraseology. Additional information concerning
6 transponder operation can be found in the AIM, chapter 4.
7
8 Radar Traffic Advisories
9 Radar equipped ATC facilities provide radar assistance to
0 aircraft on instrument flight plans and VFR aircraft provided
the aircraft can communicate with the facility and are within
Figure 13-16. Phonetic alphabet. radar coverage. This basic service includes safety alerts, traffic
advisories, limited vectoring when requested, and sequencing
of the rotating antenna when the reflected portion of the radio at locations where this procedure has been established. ATC
wave is received. issues traffic advisories based on observed radar targets. The
traffic is referenced by azimuth from the aircraft in terms of
Modern radar is very reliable and there are seldom outages. the 12-hour clock. Also, distance in nautical miles, direction
This is due to reliable maintenance and improved equipment. in which the target is moving, and type and altitude of the
There are, however, some limitations which may affect ATC aircraft, if known, are given. An example would be: “Traffic
10 o’clock 5 miles east bound, Cessna 152, 3,000 feet.” The
pilot should note that traffic position is based on the aircraft
track, and that wind correction can affect the clock position

13-14

Color and Type of Signal Movement of Vehicles, Aircraft on the Ground Aircraft in Flight
Steady green Equipment and Personnel
Flashing green Cleared for takeoff Cleared to land
Steady red Cleared to cross, Cleared for taxi
Flashing red proceed or go Stop Return for landing (to be followed
Flashing white Not applicable by steady green at the proper time)

Alternating red and green Stop Give way to other aircraft and
Clear the taxiway/runway continue circling
Return to starting point
Taxi clear of the runway Airport unsafe, do not land
on airport in use Not applicable
Exercise extreme caution!!!!
Return to starting point
on airport

Exercise extreme caution!!!! Exercise extreme caution!!!!

Figure 13-17. Light gun signals. sequencing of VFR aircraft to the primary airport. Class B
service provides approved separation of aircraft based on
at which a pilot locates traffic. This service is not intended to IFR, VFR, and/or weight, and sequencing of VFR arrivals
relieve the pilot of the responsibility to see and avoid other to the primary airport(s).
aircraft. [Figure 13-19]
Wake Turbulence
In addition to basic radar service, terminal radar service area
(TRSA) has been implemented at certain terminal locations. All aircraft generate wake turbulence while in flight. This
TRSAs are depicted on sectional aeronautical charts and disturbance is caused by a pair of counter-rotating vortices
listed in the A/FD. The purpose of this service is to provide trailing from the wingtips. The vortices from larger aircraft
separation between all participating VFR aircraft and all IFR pose problems to encountering aircraft. The wake of these
aircraft operating within the TRSA. Class C service provides aircraft can impose rolling moments exceeding the roll-
approved separation between IFR and VFR aircraft, and

SQUAWK (number) Radar Beacon Phraseology
Operate radar beacon transponder on designated code in MODE A/3.

IDENT Engage the “IDENT” feature (military I/P) of the transponder.

SQUAWK (number) and IDENT Operate transponder on specified code in MODE A/3 and engage the “IDENT”
(military I/P) feature.

SQUAWK Standby Switch transponder to standby position.

SQUAWK Low/Normal Operate transponder on low or normal sensitivity as specified. Transponder is
operated in “NORMAL” position unless ATC specifies “LOW” (“ON” is used instead of
“NORMAL” as a master control label on some types of transponders).

SQUAWK Altitude Activate MODE C with automatic altitude reporting.

STOP Altitude SQUAWK Turn off altitude reporting switch and continue transmitting MODE C framing pulses.
If your equipment does not have this capability, turn off MODE C.

STOP SQUAWK (mode in use) Switch off specified mode. (Used for military aircraft when the controller is unaware of
military service requirements for the aircraft to continue operation on another MODE.)

STOP SQUAWK Switch off transponder.

SQUAWK Mayday Operate transponder in the emergency position (MODE A Code 7700 for civil
transponder, MODE 3 Code 7700 and emergency feature for military transponder).

SQUAWK VFR Operate radar beacon transponder on Code 1200 in MODE A/3, or other
appropriate VFR code.

Figure 13-18. Transponder phraseology.

13-15

Wind wing surface, and the highest pressure under the wing. This
pressure differential triggers the rollup of the airflow aft of
TRACK TRACK the wing resulting in swirling air masses trailing downstream
of the wingtips. After the rollup is completed, the wake
consists of two counter rotating cylindrical vortices. Most of
the energy is within a few feet of the center of each vortex,
but pilots should avoid a region within about 100 feet of the
vortex core. [Figure 13-20]

Traffic information would be issued to the pilot of aircraft “A” Vortex Strength
as 12 o’clock. The actual position of the traffic as seen by The strength of the vortex is governed by the weight, speed,
the pilot of aircraft “A” would be 1 o’clock. Traffic information and shape of the wing of the generating aircraft. The vortex
issued to aircraft “B” would also be given as 12 o’clock, but characteristics of any given aircraft can also be changed by the
in this case the pilot of “B” would see traffic at 10 o’clock. extension of flaps or other wing configuration devices as well
as by a change in speed. The greatest vortex strength occurs
Figure 13-19. Traffic advisories. when the generating aircraft is heavy, clean, and slow.

control authority of the encountering aircraft. Also, the Vortex Behavior
turbulence generated within the vortices can damage aircraft Trailing vortices have certain behavioral characteristics
components and equipment if encountered at close range. For that can help a pilot visualize the wake location and take
this reason, a pilot must envision the location of the vortex avoidance precautions.
wake and adjust the flightpath accordingly.
Vortices are generated from the moment an aircraft leaves the
During ground operations and during takeoff, jet engine ground (until it touches down), since trailing vortices are the
blast (thrust stream turbulence) can cause damage and upset byproduct of wing lift. [Figure 13-21] The vortex circulation
smaller aircraft at close range. For this reason, pilots of small is outward, upward, and around the wingtips when viewed
aircraft should consider the effects of jet-engine blast and from either ahead or behind the aircraft. Tests have shown
maintain adequate separation. Also, pilots of larger aircraft that vortices remain spaced a bit less than a wingspan apart,
should consider the effects of their aircraft’s jet-engine blast drifting with the wind, at altitudes greater than a wingspan from
on other aircraft and equipment on the ground. the ground. Tests have also shown that the vortices sink at a
rate of several hundred feet per minute, slowing their descent
Vortex Generation and diminishing in strength with time and distance behind the
Lift is generated by the creation of a pressure differential over generating aircraft.
the wing surface. The lowest pressure occurs over the upper

Figure 13-20. Vortex generation.
13-16

Wake ends

25

Wake begins Touchdown

Rotation

Figure 13-21. Vortex behavior.

When the vortices of larger aircraft sink close to the ground • If departing or landing after a large aircraft executing
(within 100 to 200 feet), they tend to move laterally over a low approach, missed approach, or touch and go
the ground at a speed of 2–3 knots. A crosswind decreases landing (since vortices settle and move laterally
the lateral movement of the upwind vortex and increases the near the ground, the vortex hazard may exist along
movement of the downwind vortex. A tailwind condition can the runway and in the flightpath, particularly in a
move the vortices of the preceding aircraft forward into the quartering tailwind), it is prudent to wait at least 2
touchdown zone. minutes prior to a takeoff or landing.

Vortex Avoidance Procedures • En route it is advisable to avoid a path below and
behind a large aircraft, and if a large aircraft is
• Landing behind a larger aircraft on the same runway— observed above on the same track, change the aircraft
stay at or above the larger aircraft’s approach position laterally and preferably upwind.
flightpath and land beyond its touchdown point.
Collision Avoidance
• Landing behind a larger aircraft on a parallel runway
closer than 2,500 feet—consider the possibility of drift 14 CFR part 91 has established right-of-way rules, minimum
and stay at or above the larger aircraft’s final approach safe altitudes, and VFR cruising altitudes to enhance flight
flightpath and note its touch down point. safety. The pilot can contribute to collision avoidance by
being alert and scanning for other aircraft. This is particularly
• Landing behind a larger aircraft on crossing runway— important in the vicinity of an airport.
cross above the larger aircraft’s flightpath.
Effective scanning is accomplished with a series of short,
• Landing behind a departing aircraft on the same regularly spaced eye movements that bring successive areas
runway—land prior to the departing aircraft’s rotating of the sky into the central visual field. Each movement
point. should not exceed 10°, and each should be observed for at
least 1 second to enable detection. Although back and forth
• Landing behind a larger aircraft on a crossing eye movements seem preferred by most pilots, each pilot
runway—note the aircraft’s rotation point and, if that should develop a scanning pattern that is most comfortable
point is past the intersection, continue and land prior and then adhere to it to assure optimum scanning. Even if
to the intersection. If the larger aircraft rotates prior entitled to the right-of-way, a pilot should yield if another
to the intersection, avoid flight below its flightpath. aircraft seems too close.
Abandon the approach unless a landing is ensured
well before reaching the intersection.

• Departing behind a large aircraft—rotate prior to the
large aircraft’s rotation point and climb above its climb
path until turning clear of the wake.

• For intersection takeoffs on the same runway—be
alert to adjacent larger aircraft operations, particularly
upwind of the runway of intended use. If an intersection
takeoff clearance is received, avoid headings that cross
below the larger aircraft’s path.

13-17

Clearing Procedures to write down taxi instructions. The following are some
The following procedures and considerations should assist a practices to help prevent a runway incursion:
pilot in collision avoidance under various situations.
• Read back all runway crossing and/or hold
• Before takeoff—prior to taxiing onto a runway or instructions.
landing area in preparation for takeoff, pilots should
scan the approach area for possible landing traffic, • Review airport layouts as part of preflight planning,
executing appropriate maneuvers to provide a clear before descending to land and while taxiing, as
view of the approach areas. needed.

• Climbs and descents—during climbs and descents • Know airport signage.
in flight conditions which permit visual detection of
other traffic, pilots should execute gentle banks left • Review NOTAM for information on runway/taxiway
and right at a frequency which permits continuous closures and construction areas.
visual scanning of the airspace.
• Request progressive taxi instructions from ATC when
• Straight and level—during sustained periods of straight- unsure of the taxi route.
and-level flight, a pilot should execute appropriate
clearing procedures at periodic intervals. • Check for traffic before crossing any runway hold line
and before entering a taxiway.
• Traffic patterns—entries into traffic patterns while
descending should be avoided. • Turn on aircraft lights and the rotating beacon or strobe
lights while taxing.
• Traffic at VOR sites—due to converging traffic,
sustained vigilance should be maintained in the • When landing, clear the active runway as soon as
vicinity of VORs and intersections. possible, then wait for taxi instructions before further
movement.
• Training operations—vigilance should be maintained
and clearing turns should be made prior to a practice • Study and use proper phraseology in order to understand
maneuver. During instruction, the pilot should be and respond to ground control instructions.
asked to verbalize the clearing procedures (call out
“clear left, right, above, and below”). • Write down complex taxi instructions at unfamiliar
airports.
High-wing and low-wing aircraft have their respective blind
spots. The pilot of a high-wing aircraft should momentarily For more detailed information, contact the FAA’s Office
raise the wing in the direction of the intended turn and look of Runway Safety and Operational Services web site at
for traffic prior to commencing the turn. The pilot of a low- http://www.faa.gov/runwaysafety/ or visit http://www.aopa.
wing aircraft should momentarily lower the wing and look org/asf/accident_data/incursions.html to access a learning
for traffic prior to commencing the turn. tool developed by the FAA and the Aircraft Owners and
Pilots Association (AOPA) to help pilots and maintenance
Runway Incursion Avoidance technicians avoid runway incursions involving taxiing
A runway incursion is “any occurrence in the airport runway aircraft. Additional information can also be found in Advisory
environment involving an aircraft, vehicle, person, or object Circular (AC) 91-73, Part 91, Pilot and Flightcrew Procedures
on the ground that creates a collision hazard or results in a loss During Taxi Operations, and Part 135, Single-Pilot Procedures
of required separation with an aircraft taking off, intending During Taxi Operations.
to take off, landing, or intending to land.” It is important
to give the same attention to operating on the surface as in Chapter Summary
other phases of flights. Proper planning can prevent runway
incursions and the possibility of a ground collision. A pilot This chapter focused on airport operations both in the air and
should be aware of the aircraft’s position on the surface at all on the surface. For specific information about an unfamiliar
times and be aware of other aircraft and vehicle operations airport, consult the A/FD and NOTAMS before flying. For
on the airport. At times towered airports can be busy and taxi further information regarding procedures discussed in this
instructions complex. In this situation it may be advisable chapter, refer to 14 CFR part 91 and the AIM. By adhering
to established procedures, both airport operations and safety
are enhanced.

13-18

AirspaceChapter 14

Introduction

The two categories of airspace are: regulatory and
nonregulatory. Within these two categories there are four
types: controlled, uncontrolled, special use, and other
airspace. Figure 14-1 presents a profile view of the dimensions
of various classes of airspace. Also, there are excerpts from
sectional charts which are discussed in Chapter 15, Navigation,
that are used to illustrate how airspace is depicted.

14-1

FL 600

Class A

18,000' MSL

Class B Class E

14,500' MSL

1A,G20L0' A1,G20L0' Class C 1,200'
A70G0L' AGL Nontowered
Class G Nontowered Class DA70G0L' airport with
airport with A70G0L' Class G no instrument
instrument approach
approach Class G Class G

Figure 14-1. Airspace profile. Class C Airspace
Class C airspace is generally airspace from the surface
Controlled Airspace to 4,000 feet above the airport elevation (charted in
MSL) surrounding those airports that have an operational
Controlled airspace is a generic term that covers the control tower, are serviced by a radar approach control,
different classifications of airspace and defined dimensions and have a certain number of IFR operations or passenger
within which air traffic control (ATC) service is provided enplanements. Although the configuration of each Class C
in accordance with the airspace classification. Controlled area is individually tailored, the airspace usually consists of
airspace consists of: a surface area with a five NM radius, an outer circle with
a ten NM radius that extends from 1,200 feet to 4,000 feet
• Class A above the airport elevation, and an outer area. Each aircraft
must establish two-way radio communications with the
• Class B ATC facility providing air traffic services prior to entering
the airspace and thereafter maintain those communications
• Class C while within the airspace.

• Class D Class D Airspace
Class D airspace is generally airspace from the surface to
• Class E 2,500 feet above the airport elevation (charted in MSL)
surrounding those airports that have an operational control
Class A Airspace tower. The configuration of each Class D airspace area is
Class A airspace is generally the airspace from 18,000 feet individually tailored and when instrument procedures are
mean sea level (MSL) up to and including flight level (FL) published, the airspace is normally designed to contain the
600, including the airspace overlying the waters within 12 procedures. Arrival extensions for instrument approach
nautical miles (NM) of the coast of the 48 contiguous states procedures (IAPs) may be Class D or Class E airspace. Unless
and Alaska. Unless otherwise authorized, all operation in otherwise authorized, each aircraft must establish two-way
Class A airspace is conducted under instrument flight rules radio communications with the ATC facility providing air
(IFR). traffic services prior to entering the airspace and thereafter
maintain those communications while in the airspace.
Class B Airspace
Class B airspace is generally airspace from the surface to Class E Airspace
10,000 feet MSL surrounding the nation’s busiest airports in If the airspace is not Class A, B, C, or D, and is controlled
terms of airport operations or passenger enplanements. The airspace, then it is Class E airspace. Class E airspace extends
configuration of each Class B airspace area is individually upward from either the surface or a designated altitude to the
tailored, consists of a surface area and two or more layers
(some Class B airspace areas resemble upside-down wedding
cakes), and is designed to contain all published instrument
procedures once an aircraft enters the airspace. An ATC
clearance is required for all aircraft to operate in the area,
and all aircraft that are so cleared receive separation services
within the airspace.

14-2

overlying or adjacent controlled airspace. When designated charted as a “P” followed by a number (e.g., P-49). Examples
as a surface area, the airspace is configured to contain all of prohibited areas include Camp David and the National
instrument procedures. Also in this class are federal airways, Mall in Washington, D.C., where the White House and the
airspace beginning at either 700 or 1,200 feet above ground Congressional buildings are located. [Figure 14-2]
level (AGL) used to transition to and from the terminal or
en route environment, and en route domestic and offshore
airspace areas designated below 18,000 feet MSL. Unless
designated at a lower altitude, Class E airspace begins at
14,500 MSL over the United States, including that airspace
overlying the waters within 12 NM of the coast of the 48
contiguous states and Alaska, up to but not including 18,000
feet MSL, and the airspace above FL 600.

Uncontrolled Airspace Figure 14-2. An example of a prohibited area is Crawford, Texas.

Class G Airspace Restricted Areas
Uncontrolled airspace or Class G airspace is the portion of Restricted areas are areas where operations are hazardous to
the airspace that has not been designated as Class A, B, C, nonparticipating aircraft and contain airspace within which
D, or E. It is therefore designated uncontrolled airspace. the flight of aircraft, while not wholly prohibited, is subject
Class G airspace extends from the surface to the base of the to restrictions. Activities within these areas must be confined
overlying Class E airspace. Although ATC has no authority because of their nature, or limitations may be imposed upon
or responsibility to control air traffic, pilots should remember aircraft operations that are not a part of those activities, or
there are visual flight rules (VFR) minimums which apply both. Restricted areas denote the existence of unusual, often
to Class G airspace. invisible, hazards to aircraft (e.g., artillery firing, aerial
gunnery, or guided missiles). IFR flights may be authorized
Special Use Airspace to transit the airspace and are routed accordingly. Penetration
of restricted areas without authorization from the using
Special use airspace or special area of operation (SAO) or controlling agency may be extremely hazardous to the
is the designation for airspace in which certain activities aircraft and its occupants. ATC facilities apply the following
must be confined, or where limitations may be imposed procedures when aircraft are operating on an IFR clearance
on aircraft operations that are not part of those activities. (including those cleared by ATC to maintain VFR on top) via
Certain special use airspace areas can create limitations on a route which lies within joint-use restricted airspace:
the mixed use of airspace. The special use airspace depicted
on instrument charts includes the area name or number, 1. If the restricted area is not active and has been released
effective altitude, time and weather conditions of operation, to the Federal Aviation Administration (FAA), the
the controlling agency, and the chart panel location. On ATC facility allows the aircraft to operate in the
National Aeronautical Charting Group (NACG) en route restricted airspace without issuing specific clearance
charts, this information is available on one of the end panels. for it to do so.
Special use airspace usually consists of:
2. If the restricted area is active and has not been released
• Prohibited areas to the FAA, the ATC facility issues a clearance which
ensures the aircraft avoids the restricted airspace.
• Restricted areas

• Warning areas

• Military operation areas (MOAs)

• Alert areas

• Controlled firing areas (CFAs)

Prohibited Areas
Prohibited areas contain airspace of defined dimensions
within which the flight of aircraft is prohibited. Such areas
are established for security or other reasons associated with
the national welfare. These areas are published in the Federal
Register and are depicted on aeronautical charts. The area is

14-3

Restricted areas are charted with an “R” followed by a military training activities from IFR traffic. Whenever an
number (e.g., R-4401) and are depicted on the en route MOA is being used, nonparticipating IFR traffic may be
chart appropriate for use at the altitude or FL being flown. cleared through an MOA if IFR separation can be provided by
[Figure 14-3] Restricted area information can be obtained ATC. Otherwise, ATC reroutes or restricts nonparticipating
on the back of the chart. IFR traffic. MOAs are depicted on sectional, VFR terminal
area, and en route low altitude charts and are not numbered
(e.g., “Camden Ridge MOA”). [Figure 14-5] However, the
MOA is also further defined on the back of the sectional
charts with times of operation, altitudes affected, and the
controlling agency.

Alert Areas
Alert areas are depicted on aeronautical charts with an “A”
followed by a number (e.g., A-211) to inform nonparticipating
pilots of areas that may contain a high volume of pilot training
or an unusual type of aerial activity. Pilots should exercise
caution in alert areas. All activity within an alert area shall
be conducted in accordance with regulations, without waiver,
and pilots of participating aircraft, as well as pilots transiting
the area, shall be equally responsible for collision avoidance.
[Figure 14-6]

Figure 14-3. Restricted areas on a sectional chart. Controlled Firing Areas (CFAs)
CFAs contain activities, which, if not conducted in a controlled
Warning Areas environment, could be hazardous to nonparticipating aircraft.
Warning areas are similar in nature to restricted areas; The difference between CFAs and other special use airspace
however, the United States government does not have sole is that activities must be suspended when a spotter aircraft,
jurisdiction over the airspace. A warning area is airspace of radar, or ground lookout position indicates an aircraft might
defined dimensions, extending from 12 NM outward from be approaching the area. There is no need to chart CFAs
the coast of the United States, containing activity that may since they do not cause a nonparticipating aircraft to change
be hazardous to nonparticipating aircraft. The purpose of its flightpath.
such areas is to warn nonparticipating pilots of the potential
danger. A warning area may be located over domestic or Other Airspace Areas
international waters or both. The airspace is designated with
a “W” followed by a number (e.g., W-237). [Figure 14-4] “Other airspace areas” is a general term referring to the
majority of the remaining airspace. It includes:
Military Operation Areas (MOAs)
MOAs consist of airspace with defined vertical and lateral • Local airport advisory
limits established for the purpose of separating certain
• Military training route (MTR)

• Temporary flight restriction (TFR)

• Parachute jump aircraft operations

• Published VFR routes

• Terminal radar service area (TRSA)

• National security area (NSA)

Figure 14-4. Requirements for airspace operations. Local Airport Advisory (LAA)
14-4 A service provided by facilities, which are located on the
landing airport, have a discrete ground-to-air communication
frequency or the tower frequency when the tower is closed,
automated weather reporting with voice broadcasting, and
a continuous ASOS/AWOS data display, other continuous
direct reading instruments, or manual observations available
to the specialist.

Figure 14-5. Camden Ridge MOA is an example of a military operations area.

Figure 14-6. Alert area (A-211).

14-5

Military Training Routes (MTRs) • Protect declared national disasters for humanitarian
MTRs are routes used by military aircraft to maintain reasons in the State of Hawaii.
proficiency in tactical flying. These routes are usually
established below 10,000 feet MSL for operations at speeds • Protect the President, Vice President, or other public
in excess of 250 knots. Some route segments may be defined figures.
at higher altitudes for purposes of route continuity. Routes are
identified as IFR (IR), and VFR (VR), followed by a number. • Provide a safe environment for space agency
[Figure 14-7] MTRs with no segment above 1,500 feet operations.
AGL are identified by four number characters (e.g., IR1206,
VR1207). MTRs that include one or more segments above Since the events of September 11, 2001, the use of TFRs has
1,500 feet AGL are identified by three number characters become much more common. There have been a number
(e.g., IR206, VR207). IFR low altitude en route charts of incidents of aircraft incursions into TFRs, which have
depict all IR routes and all VR routes that accommodate resulted in pilots undergoing security investigations and
operations above 1,500 feet AGL. IR routes are conducted certificate suspensions. It is a pilot’s responsibility to be
in accordance with IFR regardless of weather conditions. aware of TFRs in their proposed area of flight. One way to
VFR sectional charts depict military training activities such check is to visit the FAA website, www.tfr.faa.gov, and verify
as IR, VR, MOA, restricted area, warning area, and alert that there is not a TFR in the area.
area information.
Parachute Jump Aircraft Operations
Parachute jump aircraft operations are published in the
Airport/Facility Directory (A/FD). Sites that are used
frequently are depicted on sectional charts.

Published VFR Routes
Published VFR routes are for transitioning around, under, or
through some complex airspace. Terms such as VFR flyway,
VFR corridor, Class B airspace VFR transition route, and
terminal area VFR route have been applied to such routes.
These routes are generally found on VFR terminal area
planning charts.

Figure 14-7. Military training route (MTR) chart symbols. Terminal Radar Service Areas (TRSAs)
TRSAs are areas where participating pilots can receive
Temporary Flight Restrictions (TFR) additional radar services. The purpose of the service is
A flight data center (FDC) Notice to Airmen (NOTAM) to provide separation between all IFR operations and
is issued to designate a TFR. The NOTAM begins with participating VFR aircraft.
the phrase “FLIGHT RESTRICTIONS” followed by the
location of the temporary restriction, effective time period, The primary airport(s) within the TRSA become(s) Class D
area defined in statute miles, and altitudes affected. The airspace. The remaining portion of the TRSA overlies other
NOTAM also contains the FAA coordination facility and controlled airspace, which is normally Class E airspace
telephone number, the reason for the restriction, and any other beginning at 700 or 1,200 feet and established to transition to/
information deemed appropriate. The pilot should check the from the en route/terminal environment. TRSAs are depicted
NOTAMs as part of flight planning. on VFR sectional charts and terminal area charts with a solid
black line and altitudes for each segment. The Class D portion
Some of the purposes for establishing a TFR are: is charted with a blue segmented line. Participation in TRSA
services is voluntary; however, pilots operating under VFR
• Protect persons and property in the air or on the surface are encouraged to contact the radar approach control and take
from an existing or imminent hazard. advantage of TRSA service.

• Provide a safe environment for the operation of National Security Areas (NSAs)
disaster relief aircraft. NSAs consist of airspace of defined vertical and lateral
dimensions established at locations where there is a
• Prevent an unsafe congestion of sightseeing aircraft requirement for increased security and safety of ground
above an incident or event, which may generate a high facilities. Flight in NSAs may be temporarily prohibited by
degree of public interest.

14-6

regulation under the provisions of Title 14 of the Code of 1. The controller within whose area of jurisdiction the
Federal Regulations (14 CFR) part 99, and prohibitions are control instructions are issued.
disseminated via NOTAM. Pilots are requested to voluntarily
avoid flying through these depicted areas. 2. The controller receiving the transfer of control.

Air Traffic Control and the National 3. Any intervening controller(s) through whose area of
Airspace System jurisdiction the aircraft will pass.

The primary purpose of the ATC system is to prevent a If ATC issues control instructions to an aircraft through a
collision between aircraft operating in the system and to source other than another controller (e.g., Aeronautical Radio,
organize and expedite the flow of traffic. In addition to Incorporated (ARINC), Automated Flight Service Station/
its primary function, the ATC system has the capability to Flight Service Station (AFSS/FSS), another pilot) they ensure
provide (with certain limitations) additional services. The that the necessary coordination has been accomplished with
ability to provide additional services is limited by many any controllers listed above, whose area of jurisdiction is
factors, such as the volume of traffic, frequency congestion, affected by those instructions unless otherwise specified by
quality of radar, controller workload, higher priority duties, a letter of agreement or a facility directive.
and the pure physical inability to scan and detect those
situations that fall in this category. It is recognized that these Operating in the Various Types of Airspace
services cannot be provided in cases in which the provision It is important that pilots be familiar with the operational
of services is precluded by the above factors. requirements for each of the various types or classes of
airspace. Subsequent sections cover each class in sufficient
Consistent with the aforementioned conditions, controllers detail to facilitate understanding with regard to weather, type
shall provide additional service procedures to the extent of pilot certificate held, as well as equipment required.
permitted by higher priority duties and other circumstances.
The provision of additional services is not optional on the Basic VFR Weather Minimums
part of the controller, but rather is required when the work No pilot may operate an aircraft under basic VFR when the
situation permits. Provide ATC service in accordance with flight visibility is less, or at a distance from clouds that is
the procedures and minima in this order except when: less, than that prescribed for the corresponding altitude and
class of airspace. [Figure 14-9] Except as provided in 14
1. A deviation is necessary to conform with ICAO CFR Section 91.157, Special VFR Weather Minimums, no
Documents, National Rules of the Air, or special person may operate an aircraft beneath the ceiling under
agreements where the United States provides ATC VFR within the lateral boundaries of controlled airspace
service in airspace outside the country and its designated to the surface for an airport when the ceiling is
possessions or: less than 1,000 feet. Additional information can be found in
14 CFR section 91.155(c).
2. Other procedures/minima are prescribed in a letter of
agreement, FAA directive, or a military document, Operating Rules and Pilot/Equipment Requirements
or: The safety of flight is a top priority of all pilots and the
responsibilities associated with operating an aircraft
3. A deviation is necessary to assist an aircraft when an should always be taken seriously. The air traffic system
emergency has been declared. maintains a high degree of safety and efficiency with strict
regulatory oversight of the FAA. Pilots fly in accordance
Coordinating the Use of Airspace with regulations that have served the United States well, as
ATC is responsible for ensuring that the necessary evidenced by the fact that the country has the safest aviation
coordination has been accomplished before allowing an system in the world.
aircraft under their control to enter another controller’s area
of jurisdiction.

Before issuing control instructions directly or relaying All aircraft operating in today’s National Airspace System
through another source to an aircraft which is within (NAS) has complied with the CFR governing its certification
another controller’s area of jurisdiction that will change that and maintenance; all pilots operating today have completed
aircraft’s heading, route, speed, or altitude, ATC ensures rigorous pilot certification training and testing. Of equal
that coordination has been accomplished with each of the importance is the proper execution of preflight planning,
controllers listed below whose area of jurisdiction is affected aeronautical decision-making (ADM) and risk management.
by those instructions unless otherwise specified by a letter ADM involves a systematic approach to risk assessment
of agreement or a facility directive: and stress management in aviation, illustrates how personal

14-7

attitudes can influence decision-making, and how those received prior to entering the airspace. Unless otherwise

attitudes can be modified to enhance safety in the flight authorized by ATC, each aircraft operating in Class A

deck. More detailed information regarding ADM and airspace must be equipped with a two-way radio capable of

risk mitigation can be found in Chapter 17, Aeronautical communicating with ATC on a frequency assigned by ATC.

Decision-Making. Unless otherwise authorized by ATC, all aircraft within Class

A airspace must be equipped with the appropriate transponder

Pilots also comply with very strict FAA general operating equipment meeting all applicable specifications found in 14

and flight rules as outlined in the CFR, including the FAA’s CFR section 91.215.

important “see and avoid” mandate. These regulations

provide the historical foundation of the FAA regulations Class B

governing the aviation system and the individual classes of All pilots operating an aircraft within a Class B airspace area
airspace. Figure 14-10 lists the operational and equipment must receive an ATC clearance from the ATC facility having
requirements for these various classes of airspace. It will jurisdiction for that area. The pilot in command (PIC) may
be helpful to refer to this figure as the specific classes are not take off or land an aircraft at an airport within a Class
discussed in greater detail. B airspace unless he or she has met one of the following

Class A requirements:
Pilots operating an aircraft in Class A airspace must conduct
1. A private pilot certificate.

that operation under IFR and only under an ATC clearance 2. A recreational pilot certificate and all requirements
Basic VFR Weather Minimumcosntained within 14 CFR section 61.101(d), or the

Airspace Flight Visibility Distance from Clouds

Class A Not applicable Not applicable

Class B 3 statute miles Clear of clouds

Class C 3 statute miles 1,000 feet above
500 feet below
2,000 feet horizontal

Class D 3 statute miles 1,000 feet above
500 feet below
2,000 feet horizontal

Class E At or above 5 statute miles 1,000 feet above
10,000 feet MSL 1,000 feet below
1 statute mile horizontal

Less than 3 statute miles 1,000 feet above
10,000 feet MSL 500 feet below
2,000 feet horizontal

Class G 1,200 feet or less Day, except as provided in section 91.155(b) 1 statute mile Clear of clouds
above the surface Night, except as provided in section 91.155(b) 3 statute miles
1,000 feet above
(regardless of 500 feet below
MSL altitude). 2,000 feet horizontal

More than 1,200 Day 1 statute mile 1,000 feet above
feet above the Night 3 statute miles 500 feet below
surface but less 5 statute miles 2,000 feet horizontal
than 10,000 feet
1,000 feet above
MSL. 500 feet below
2,000 feet horizontal
More than 1,200 feet
above the surface 1,000 feet above
and at or above 1,000 feet below
10,000 feet MSL. 1 statute mile horizontal

Figure 14-9. Visual flight rule weather minimums.

14-8

requirements for a student pilot seeking a recreational and maintain two-way radio communications with the ATC
pilot certificate in 14 CFR section 61.94. facility having jurisdiction over the Class C airspace area as
soon as practicable after departing.
3. A sport pilot certificate and all requirements contained
within 14 CFR section 61.325, or the requirements for Unless otherwise authorized by the ATC having jurisdiction
a student pilot seeking a recreational pilot certificate over the Class C airspace area, all aircraft within Class C
in 14 CFR section 61.94, or the aircraft is operated airspace must be equipped with the appropriate transponder
by a student pilot who has met the requirements of 14 equipment meeting all applicable specifications found in 14
CFR sections 61.94 and 61.95, as applicable. CFR section 91.215.

Unless otherwise authorized by ATC, all aircraft within Class Class D
B airspace must be equipped with the applicable operating
transponder and automatic altitude reporting equipment No pilot may take off or land an aircraft at a satellite airport
specified in 14 CFR section 91.215(a) and an operable within a Class D airspace area except in compliance with
two-way radio capable of communications with ATC on FAA arrival and departure traffic patterns. A pilot departing
appropriate frequencies for that Class B airspace area. from the primary airport or satellite airport with an operating
control tower must establish and maintain two-way radio
Class C communications with the control tower, and thereafter as
For the purpose of this section, the primary airport is the instructed by ATC while operating in the Class D airspace
airport for which the Class C airspace area is designated. A area. If departing from a satellite airport without an operating
satellite airport is any other airport within the Class C airspace control tower, the pilot must establish and maintain two-
area. No pilot may take off or land an aircraft at a satellite way radio communications with the ATC facility having
airport within a Class C airspace area except in compliance jurisdiction over the Class D airspace area as soon as
with FAA arrival and departure traffic patterns. practicable after departing.

Two-way radio communications must be established and Two-way radio communications must be established and
maintained with the ATC facility providing air traffic services maintained with the ATC facility providing air traffic services
prior to entering the airspace and thereafter maintained while prior to entering the airspace and thereafter maintained while
within the airspace. within the airspace.

A pilot departing from the primary airport or satellite airport If the aircraft radio fails in flight under IFR, the pilot
with an operating control tower must establish and maintain should continue the flight by the route assigned in the last
two-way radio communications with the control tower, ATC clearance received; or, if being radar vectored, by the
and thereafter as instructed by ATC while operating in the direct route from the point of radio failure to the fix, route,
Class C airspace area. If departing from a satellite airport or airway specified in the vector clearance. In the absence
without an operating control tower, the pilot must establish of an assigned route, the pilot should continue by the route

Class Entry Requirements Equipment Minimum Pilot Certificate
Airspace ATC clearance IFR equipped Instrument rating
ATC clearance Two-way radio, transponder Private—(However, a student or
A with altitude reporting capability recreational pilot may operate at
other than the primary airport if
B seeking private pilot certification and
if regulatory requirements are met.)
C Two-way radio communications Two-way radio, transponder No specific requirement
prior to entry with altitude reporting capability
Two-way radio No specific requirement
D Two-way radio communications
prior to entry No specific requirement No specific requirement
No specific requirement No specific requirement
E None for VFR
G None
Figure 14-10. Requirements for airspace operations.

14-9

that ATC advised may be expected in a further clearance; Unless otherwise authorized or required by ATC, no person
or, if a route had not been advised, by the route filed in the may operate an aircraft to, from, through, or on an airport
flight plan. having an operational control tower unless two-way radio
communications are maintained between that aircraft and the
If the aircraft radio fails in flight under VFR, the PIC may control tower. Communications must be established prior to
operate that aircraft and land if weather conditions are at or four nautical miles from the airport, up to and including 2,500
above basic VFR weather minimums, visual contact with the feet AGL. However, if the aircraft radio fails in flight, the
tower is maintained, and a clearance to land is received. pilot in command may operate that aircraft and land if weather
conditions are at or above basic VFR weather minimums,
Class E visual contact with the tower is maintained, and a clearance
Unless otherwise required by 14 CFR part 93 or unless to land is received.
otherwise authorized or required by the ATC facility having
jurisdiction over the Class E airspace area, each pilot If the aircraft radio fails in flight under IFR, the pilot
operating an aircraft on or in the vicinity of an airport in a should continue the flight by the route assigned in the last
Class E airspace area must comply with the requirements of ATC clearance received; or, if being radar vectored, by the
Class G airspace. Each pilot must also comply with any traffic direct route from the point of radio failure to the fix, route,
patterns established for that airport in 14 CFR part 93. or airway specified in the vector clearance. In the absence
of an assigned route, the pilot should continue by the route
Unless otherwise authorized or required by ATC, no person that ATC advised may be expected in a further clearance;
may operate an aircraft to, from, through, or on an airport or, if a route had not been advised, by the route filed in the
having an operational control tower unless two-way radio flight plan.
communications are maintained between that aircraft and
the control tower. Communications must be established prior Ultralight Vehicles
to four nautical miles from the airport, up to and including No person may operate an ultralight vehicle within Class A,
2,500 feet AGL. However, if the aircraft radio fails in Class B, Class C, or Class D airspace or within the lateral
flight, the PIC may operate that aircraft and land if weather boundaries of the surface area of Class E airspace designated
conditions are at or above basic VFR weather minimums, for an airport unless that person has prior authorization from
visual contact with the tower is maintained, and a clearance the ATC facility having jurisdiction over that airspace. (See
to land is received. 14 CFR part 103.)

If the aircraft radio fails in flight under IFR, the pilot Unmanned Free Balloons
should continue the flight by the route assigned in the last Unless otherwise authorized by ATC, no person may operate
ATC clearance received; or, if being radar vectored, by the an unmanned free balloon below 2,000 feet above the surface
direct route from the point of radio failure to the fix, route, within the lateral boundaries of Class B, Class C, Class D,
or airway specified in the vector clearance. In the absence or Class E airspace designated for an airport. (See 14 CFR
of an assigned route, the pilot should continue by the route part 101.)
that ATC advised may be expected in a further clearance;
or, if a route had not been advised, by the route filed in the Parachute Jumps
flight plan. No person may make a parachute jump, and no PIC may
allow a parachute jump to be made from that aircraft, in or
Class G into Class A, Class B, Class C, or Class D airspace without,
or in violation of, the terms of an ATC authorization issued
When approaching to land at an airport without an operating by the ATC facility having jurisdiction over the airspace.
control tower in Class G airspace: (See 14 CFR part 105.)

1. Each pilot of an airplane must make all turns of that Chapter Summary
airplane to the left unless the airport displays approved
light signals or visual markings indicating that turns This chapter introduces the various classifications of airspace
should be made to the right, in which case the pilot and provides information on the requirements to operate in
must make all turns to the right. such airspace. For further information, consult the AIM and
14 CFR parts 71, 73, and 91.
2. Each pilot of a helicopter or a powered parachute must
avoid the flow of fixed-wing aircraft.

14-10

NChapaterv15igation

Introduction

This chapter provides an introduction to cross-country
flying under visual flight rules (VFR). It contains practical
information for planning and executing cross-country flights
for the beginning pilot.
Air navigation is the process of piloting an aircraft from
one geographic position to another while monitoring one’s
position as the flight progresses. It introduces the need for
planning, which includes plotting the course on an aeronautical
chart, selecting checkpoints, measuring distances, obtaining
pertinent weather information, and computing flight time,
headings, and fuel requirements. The methods used in this
chapter include pilotage—navigating by reference to visible
landmarks, dead reckoning—computations of direction and
distance from a known position, and radio navigation—by
use of radio aids.

15-1

Aeronautical Charts The charts provide an abundance of information, including
airport data, navigational aids, airspace, and topography.
An aeronautical chart is the road map for a pilot flying under Figure 15-1 is an excerpt from the legend of a sectional
VFR. The chart provides information which allows pilots chart. By referring to the chart legend, a pilot can interpret
to track their position and provides available information most of the information on the chart. A pilot should also
which enhances safety. The three aeronautical charts used check the chart for other legend information, which includes
by VFR pilots are: air traffic control (ATC) frequencies and information on
airspace. These charts are revised semiannually except for
• Sectional some areas outside the conterminous United States where
they are revised annually.
• VFR Terminal Area
VFR Terminal Area Charts
• World Aeronautical VFR terminal area charts are helpful when flying in or near
Class B airspace. They have a scale of 1:250,000 (1 inch
A free catalog listing aeronautical charts and related = 3.43 NM or approximately 4 SM). These charts provide
publications including prices and instructions for ordering a more detailed display of topographical information and
is available at the National Aeronautical Charting Group are revised semiannually, except for several Alaskan and
(NACG) web site: www.naco.faa.gov. Caribbean charts. [Figure 15-2]

Sectional Charts World Aeronautical Charts
Sectional charts are the most common charts used by pilots World aeronautical charts are designed to provide a standard
today. The charts have a scale of 1:500,000 (1 inch = 6.86 series of aeronautical charts, covering land areas of the
nautical miles (NM) or approximately 8 statute miles (SM))
which allows for more detailed information to be included
on the chart.

Figure 15-1. Sectional chart and legend.
15-2

Figure 15-2. VFR terminal area chart and legend. Meridians of longitude are drawn from the North Pole to the
South Pole and are at right angles to the Equator. The “Prime
world, at a size and scale convenient for navigation by Meridian” which passes through Greenwich, England, is
moderate speed aircraft. They are produced at a scale of used as the zero line from which measurements are made in
1:1,000,000 (1 inch = 13.7 NM or approximately 16 SM). degrees east (E) and west (W) to 180°. The 48 conterminous
These charts are similar to sectional charts and the symbols states of the United States are between 67° and 125° W
are the same except there is less detail due to the smaller longitude. The arrows in Figure 15-4 labeled “Longitude”
scale. [Figure 15-3] point to lines of longitude.

These charts are revised annually except several Alaskan Any specific geographical point can be located by reference
charts and the Mexican/Caribbean charts which are revised to its longitude and latitude. Washington, D.C., for example,
every 2 years. is approximately 39° N latitude, 77° W longitude. Chicago
is approximately 42° N latitude, 88° W longitude.
Lattitude and Longitude (Meridians and
Parallels) Time Zones
The meridians are also useful for designating time zones. A
The equator is an imaginary circle equidistant from the poles day is defined as the time required for the Earth to make one
of the Earth. Circles parallel to the equator (lines running east complete rotation of 360°. Since the day is divided into 24
and west) are parallels of latitude. They are used to measure hours, the Earth revolves at the rate of 15° an hour. Noon is
degrees of latitude north (N) or south (S) of the equator. The the time when the sun is directly above a meridian; to the west
angular distance from the equator to the pole is one-fourth of that meridian is morning, to the east is afternoon.
of a circle or 90°. The 48 conterminous states of the United
States are located between 25° and 49° N latitude. The arrows
in Figure 15-4 labeled “Latitude” point to lines of latitude.

15-3

Figure 15-3. World aeronautical chart. The standard practice is to establish a time zone for each
15° of longitude. This makes a difference of exactly 1 hour
90°N between each zone. In the United States, there are four time
75°N zones. The time zones are Eastern (75°), Central (90°),
60°N Mountain (105°), and Pacific (120°). The dividing lines are
somewhat irregular because communities near the boundaries
45°N often find it more convenient to use time designations of
neighboring communities or trade centers.
30°N
Figure 15-5 shows the time zones in the United States.
15°N When the sun is directly above the 90th meridian, it is noon
Prime merid11ia55n°°WW Central Standard Time. At the same time, it is 1 p.m. Eastern
Standard Time, 11 a.m. Mountain Standard Time, and 10
30°W a.m. Pacific Standard Time. When Daylight Saving Time is
45°W in effect, generally between the second Sunday in March and
the first Sunday in November, the sun is directly above the
Latitude 60°W 75th meridian at noon, Central Daylight Time.

75°W

90°W

105°W
120°W

135°W

115500°°WW

Longitude Equator
15°S

30°S

45°S
60°S

Figure 15-4. Meridians and parallels—the basis of measuring time,
distance, and direction.

15-4

Pacific Standard Time Mountain Standard Time Central Standard Time Eastern Standard Time

75°

120°

105° 90°

Figure 15-5. Time zones.

These time zone differences must be taken into account the world are based on this reference. To convert to this time,
during long flights eastward—especially if the flight must a pilot should do the following:
be completed before dark. Remember, an hour is lost when
flying eastward from one time zone to another, or perhaps Eastern Standard Time..........Add 5 hours
even when flying from the western edge to the eastern edge
of the same time zone. Determine the time of sunset at the Central Standard Time..........Add 6 hours
destination by consulting the flight service stations (AFSS/
FSS) or National Weather Service (NWS) and take this into Mountain Standard Time...... Add 7 hours
account when planning an eastbound flight.
Pacific Standard Time.......... Add 8 hours
In most aviation operations, time is expressed in terms of
the 24-hour clock. ATC instructions, weather reports and For Daylight Saving Time, 1 hour should be subtracted from
broadcasts, and estimated times of arrival are all based on the calculated times.
this system. For example: 9 a.m. is expressed as 0900, 1 p.m.
is 1300, and 10 p.m. is 2200. Measurement of Direction
By using the meridians, direction from one point to another
Because a pilot may cross several time zones during a flight, a can be measured in degrees, in a clockwise direction from
standard time system has been adopted. It is called Universal true north. To indicate a course to be followed in flight, draw a
Coordinated Time (UTC) and is often referred to as Zulu line on the chart from the point of departure to the destination
time. UTC is the time at the 0° line of longitude which passes and measure the angle which this line forms with a meridian.
through Greenwich, England. All of the time zones around Direction is expressed in degrees, as shown by the compass
rose in Figure 15-6.

15-5

3 33 the true course. This is discussed more fully in subsequent
36 sections in this chapter. For the purpose of this discussion,
NNW N NNE assume a no-wind condition exists under which heading and
course would coincide. Thus, for a true course of 065°, the
W N true heading would be 065°. To use the compass accurately,
however, corrections must be made for magnetic variation
30 24WNW NEN12 6 and compass deviation.
27 15
N E Variation
Variation is the angle between true north and magnetic north.
W E It is expressed as east variation or west variation depending
upon whether magnetic north (MN) is to the east or west of
SW ESE true north (TN).
W
E S
W

SSW S SSE The north magnetic pole is located close to 71° N latitude, 96°
W longitude and is about 1,300 miles from the geographic
S or true north pole, as indicated in Figure 15-8. If the Earth
21 15 were uniformly magnetized, the compass needle would point
18 toward the magnetic pole, in which case the variation between
true north (as shown by the geographical meridians) and
Figure 15-6. Compass rose. magnetic north (as shown by the magnetic meridians) could
be measured at any intersection of the meridians.
Because meridians converge toward the poles, course
measurement should be taken at a meridian near the midpoint
of the course rather than at the point of departure. The course
measured on the chart is known as the true course (TC). This
is the direction measured by reference to a meridian or true
north. It is the direction of intended flight as measured in
degrees clockwise from true north.

As shown in Figure 15-7, the direction from A to B would TN
be a true course of 065°, whereas the return trip (called the
reciprocal) would be a true course of 245°.

Course A to B 065° B MN

065°
245
°

A Course B to A 245° Figure 15-8. Magnetic meridians are in red while the lines of
longitude and latitude are in blue. From these lines of variation
Figure 15-7. Courses are determined by reference to meridians on (magnetic meridians), one can determine the effect of local magnetic
aeronautical charts. variations on a magnetic compass.

The true heading (TH) is the direction in which the nose of Actually, the Earth is not uniformly magnetized. In the United
the aircraft points during a flight when measured in degrees States, the needle usually points in the general direction of
clockwise from true north. Usually, it is necessary to head the magnetic pole, but it may vary in certain geographical
the aircraft in a direction slightly different from the true localities by many degrees. Consequently, the exact amount
course to offset the effect of wind. Consequently, numerical of variation at thousands of selected locations in the United
value of the true heading may not correspond with that of States has been carefully determined. The amount and the

15-6

direction of variation, which change slightly from time west of the Great Lakes, south through Wisconsin, Illinois,
to time, are shown on most aeronautical charts as broken western Tennessee, and along the border of Mississippi and
magenta lines, called isogonic lines, which connect points Alabama. [Compare Figures 15-9 and 15-10.]
of equal magnetic variation. (The line connecting points at
which there is no variation between true north and magnetic Because courses are measured in reference to geographical
north is the agonic line.) An isogonic chart is shown in meridians which point toward true north, and these courses are
Figure 15-9. Minor bends and turns in the isogonic and agonic maintained by reference to the compass which points along a
lines are caused by unusual geological conditions affecting magnetic meridian in the general direction of magnetic north,
magnetic forces in these areas. the true direction must be converted into magnetic direction
for the purpose of flight. This conversion is made by adding
Easterly Variation Westerly Variation or subtracting the variation which is indicated by the nearest
isogonic line on the chart.

For example, a line drawn between two points on a chart
is called a true course as it is measured from true north.
However, flying this course off the magnetic compass would
not provide an accurate course between the two points due to
three elements that must be considered. The first is magnetic
variation, the second is compass deviation, and the third is
wind correction. All three must be considered for accurate
navigation.

Agonic Line Magnetic Variation

Figure 15-9. Note the agonic line where magnetic variation is As mentioned in the paragraph discussing variation, the
zero. appropriate variation for the geographical location of
the flight must be considered and added or subtracted as
appropriate. If flying across an area where the variation
changes, then the values must be applied along the route of
flight appropriately. Once applied, this new course is called
the magnetic course.

On the west coast of the United States, the compass needle Magnetic Deviation
points to the east of true north; on the east coast, the compass
needle points to the west of true north. Because each aircraft has its own internal effect upon the
onboard compass systems from its own localized magnetic
Zero degree variation exists on the agonic line, where influencers, the pilot must add or subtract these influencers
magnetic north and true north coincide. This line runs roughly based upon the direction he or she is flying. The application of

NP NP NP

variaEtioenst MP MP MP Wveasritation

vZaerrioation

N 33 3 N 33 3 N 33 3

30 W 24
30 W 24
30 W 24
12 6
E

12 6
E

12 6
E

21 S 15 21 S 15 21 S 15

SP SP SP
Figure 15-10. Effect of variation on the compass.
15-7

deviation (taken from a compass deviation card) compensates Magnetic North
the magnetic course unique to that aircraft’s compass system
(as affected by localized magnetic influencers) and it now Magnetic North Magnetic North
becomes the compass course. Therefore, the compass course
when followed (in a no wind condition) takes the aircraft from N 33 3
point A to point B even though the aircraft heading may not
match the original course line drawn on the chart. 30 W 24
30 W 24

30 W 24
If the variation is shown as “9° E,” this means that magnetic N 33 3 21 S 1512 6 N 33 3
north is 9° east of true north. If a true course of 360° is to be E
flown, 9° must be subtracted from 360°, which results in a 12 6
magnetic heading of 351°. To fly east, a magnetic course of E
081° (090° – 9°) would be flown. To fly south, the magnetic
course would be 171° (180° – 9°). To fly west, it would be 12 6
261° (270° – 9°). To fly a true heading of 060°, a magnetic E
course of 051° (060° – 9°) would be flown.
21 S 15 21 S 15

Remember, if variation is west, add; if east, subtract. One Figure 15-11. Magnetized portions of the airplane cause the
method for remembering whether to add or subtract variation compass to deviate from its normal indications.
is the phrase “east is least (subtract) and west is best (add).”
are turned on. Tailwheel-type aircaft should be jacked up
Deviation into flying position. The aircraft is aligned with magnetic
Determining the magnetic heading is an intermediate step north indicated on the compass rose and the reading shown
necessary to obtain the correct compass heading for the flight. on the compass is recorded on a deviation card. The aircraft
To determine compass heading, a correction for deviation is then aligned at 30° intervals and each reading is recorded.
must be made. Because of magnetic influences within If the aircraft is to be flown at night, the lights are turned on
an aircraft such as electrical circuits, radio, lights, tools, and any significant changes in the readings are noted. If so,
engine, and magnetized metal parts, the compass needle is additional entries are made for use at night.
frequently deflected from its normal reading. This deflection
is deviation. The deviation is different for each aircraft, and it The accuracy of the compass can also be checked by
also may vary for different headings in the same aircraft. For comparing the compass reading with the known runway
instance, if magnetism in the engine attracts the north end of headings.
the compass, there would be no effect when the plane is on a
heading of magnetic north. On easterly or westerly headings, A deviation card, similar to Figure 15-12, is mounted near
however, the compass indications would be in error, as shown the compass, showing the addition or subtraction required to
in Figure 15-11. Magnetic attraction can come from many correct for deviation on various headings, usually at intervals
other parts of the aircraft; the assumption of attraction in the of 30°. For intermediate readings, the pilot should be able to
engine is merely used for the purpose of illustration. interpolate mentally with sufficient accuracy. For example,
if the pilot needed the correction for 195° and noted the
Some adjustment of the compass, referred to as compensation, correction for 180° to be 0° and for 210° to be +2°, it could
can be made to reduce this error, but the remaining correction be assumed that the correction for 195° would be +1°. The
must be applied by the pilot. magnetic heading, when corrected for deviation, is known
as compass heading.
Proper compensation of the compass is best performed by
a competent technician. Since the magnetic forces within For (Magnetic) N 30 60 E 120 150
the aircraft change, because of landing shocks, vibration, Steer (Compass) 0 28 57 86 117 148
mechanical work, or changes in equipment, the pilot should For (Magnetic S 210 240 W 300 330
occasionally have the deviation of the compass checked. The Steer (Compass) 180 212 243 274 303 332
procedure used to check the deviation (called “swinging the
compass”) is briefly outlined. Figure 15-12. Compass deviation card.

The aircraft is placed on a magnetic compass rose, the engine
started, and electrical devices normally used (such as radio)

15-8

Effect of Wind WINDS ARE CALM

The preceding discussion explained how to measure a true 090°
course on the aeronautical chart and how to make corrections
for variation and deviation, but one important factor has not Groundspeed 120 knots 090°
been considered—wind. As discussed in the study of the
atmosphere, wind is a mass of air moving over the surface of WINDS 270° AT 20 KNOTS
the Earth in a definite direction. When the wind is blowing
from the north at 25 knots, it simply means that air is moving Groundspeed 140 knots
southward over the Earth’s surface at the rate of 25 NM in
1 hour. WINDS 090° AT 20 KNOTS

Under these conditions, any inert object free from contact 090°
with the Earth is carried 25 NM southward in 1 hour. This
effect becomes apparent when such things as clouds, dust,
and toy balloons are observed being blown along by the wind.
Obviously, an aircraft flying within the moving mass of air
is similarly affected. Even though the aircraft does not float
freely with the wind, it moves through the air at the same time
the air is moving over the ground, thus is affected by wind.
Consequently, at the end of 1 hour of flight, the aircraft is in
a position which results from a combination of the following
two motions:

• Movement of the air mass in reference to the ground

• Forward movement of the aircraft through the air
mass

Actually, these two motions are independent. It makes no Groundspeed 100 knots
difference whether the mass of air through which the aircraft
is flying is moving or is stationary. A pilot flying in a 70- Figure 15-13. Motion of the air affects the speed with which aircraft
knot gale would be totally unaware of any wind (except for move over the Earth’s surface. Airspeed, the rate at which an
possible turbulence) unless the ground were observed. In aircraft moves through the air, is not affected by air motion.
reference to the ground, however, the aircraft would appear
to fly faster with a tailwind or slower with a headwind, or to the movement of the aircraft with that of the air mass. GS can
drift right or left with a crosswind. be measured as the distance from the point of departure to
the position of the aircraft at the end of 1 hour. The GS can
As shown in Figure 15-13, an aircraft flying eastward at an be computed by the time required to fly between two points a
airspeed of 120 knots in still air has a groundspeed (GS) known distance apart. It also can be determined before flight
exactly the same—120 knots. If the mass of air is moving by constructing a wind triangle, which is explained later in
eastward at 20 knots, the airspeed of the aircraft is not this chapter. [Figure 15-14]
affected, but the progress of the aircraft over the ground is
120 plus 20, or a GS of 140 knots. On the other hand, if the The direction in which the aircraft is pointing as it flies
mass of air is moving westward at 20 knots, the airspeed of is heading. Its actual path over the ground, which is a
the aircraft remains the same, but GS becomes 120 minus combination of the motion of the aircraft and the motion of
20, or 100 knots. the air, is its track. The angle between the heading and the
track is drift angle. If the aircraft heading coincides with the
Assuming no correction is made for wind effect, if an aircraft true course and the wind is blowing from the left, the track
is heading eastward at 120 knots, and the air mass moving does not coincide with the true course. The wind causes the
southward at 20 knots, the aircraft at the end of 1 hour is aircraft to drift to the right, so the track falls to the right of
almost 120 miles east of its point of departure because of its the desired course or true course. [Figure 15-15]
progress through the air. It is 20 miles south because of the
motion of the air. Under these circumstances, the airspeed
remains 120 knots, but the GS is determined by combining

15-9

Airspeed effect (1 hour) 20 knots
Distance covered over ground (1 hour)

Figure 15-14. Aircraft flightpath resulting from its airspeed and direction, and the wind speed and direction.

Wind

Heading Desired course
Drift angle

Track

Figure 15-15. Effects of wind drift on maintaining desired course. TN MN CNDEV 4°
MH-0C7H-074
The following method is used by many pilots to determine VAR 10° E °
compass heading: after the TC is measured, and wind TH-08°
correction applied resulting in a TH, the sequence TH ± 88°
variation (V) = magnetic heading (MH) ± deviation (D) Heading
= compass heading (CH) is followed to arrive at compass
heading. [Figure 15-16] Figure 15-16. Relationship between true, magnetic, and compass
headings for a particular instance.
By determining the amount of drift, the pilot can counteract
the effect of the wind and make the track of the aircraft
coincide with the desired course. If the mass of air is moving
across the course from the left, the aircraft drifts to the
right, and a correction must be made by heading the aircraft
sufficiently to the left to offset this drift. To state in another
way, if the wind is from the left, the correction is made by
pointing the aircraft to the left a certain number of degrees,
therefore correcting for wind drift. This is the wind correction
angle (WCA) and is expressed in terms of degrees right or
left of the true course. [Figure 15-17]

15-10

075°

Wind Heading

Wind Desired course 090°
correction
angle

Track

Figure 15-17. Establishing a wind correction angle that will counteract wind drift and maintain the desired course.

To summarize: 140, or 1.5 hours. (The 0.5 hour multiplied by 60 minutes
equals 30 minutes.) Answer: 1:30.
• Course—intended path of an aircraft over the ground
or the direction of a line drawn on a chart representing Distance D = GS X T
the intended aircraft path, expressed as the angle To find the distance flown in a given time, multiply GS by
measured from a specific reference datum clockwise time. The distance flown in 1 hour 45 minutes at a GS of 120
from 0° through 360° to the line. knots is 120 x 1.75, or 210 NM.

• Heading—direction in which the nose of the aircraft GS GS = D/T
points during flight. To find the GS, divide the distance flown by the time required.
If an aircraft flies 270 NM in 3 hours, the GS is 270 ÷ 3 =
• Track—actual path made over the ground in flight. (If 90 knots.
proper correction has been made for the wind, track
and course are identical.) Converting Knots to Miles Per Hour
Another conversion is that of changing knots to miles per hour
• Drift angle—angle between heading and track. (mph). The aviation industry is using knots more frequently
than mph, but it might be well to discuss the conversion for
• WCA—correction applied to the course to establish those that use mph when working with speed problems. The
a heading so that track coincides with course. NWS reports both surface winds and winds aloft in knots.
However, airspeed indicators in some aircraft are calibrated
• Airspeed—rate of the aircraft’s progress through the in mph (although many are now calibrated in both miles per
air. hour and knots). Pilots, therefore, should learn to convert
wind speeds that are reported in knots to mph.
• GS—rate of the aircraft’s inflight progress over the
ground. A knot is 1 nautical mile per hour (NMPH). Because there are
6,076.1 feet in 1 NM and 5,280 feet in 1 SM, the conversion
Basic Calculations factor is 1.15. To convert knots to miles per hour, multiply
speed in knots by 1.15. For example: a wind speed of 20
Before a cross-country flight, a pilot should make common knots is equivalent to 23 mph.
calculations for time, speed, and distance, and the amount
of fuel required. Most flight computers or electronic calculators have a
means of making this conversion. Another quick method of
Converting Minutes to Equivalent Hours conversion is to use the scales of NM and SM at the bottom
Frequently, it is necessary to convert minutes into equivalent of aeronautical charts.
hours when solving speed, time, and distance problems. To
convert minutes to hours, divide by 60 (60 minutes = 1 hour).
Thus, 30 minutes is 30/60 = 0.5 hour. To convert hours to
minutes, multiply by 60. Thus, 0.75 hour equals 0.75 x 60
= 45 minutes.

Time T = D/GS

To find the time (T) in flight, divide the distance (D) by the
GS. The time to fly 210 NM at a GS of 140 knots is 210 ÷

15-11

Fuel Consumption ample checkpoints. If one is missed, look for the next one
Aircraft fuel consumption is computed in gallons per hour. while maintaining the heading. When determining position
Consequently, to determine the fuel required for a given from checkpoints, remember that the scale of a sectional chart
flight, the time required for the flight must be known. Time is 1 inch = 8 SM or 6.86 NM. For example, if a checkpoint
in flight multiplied by rate of consumption gives the quantity selected was approximately one-half inch from the course
of fuel required. For example, a flight of 400 NM at a GS of line on the chart, it is 4 SM or 3.43 NM from the course on
100 knots requires 4 hours. If an aircraft consumes 5 gallons the ground. In the more congested areas, some of the smaller
an hour, the total consumption is 4 x 5, or 20 gallons. features are not included on the chart. If confused, hold the
heading. If a turn is made away from the heading, it is easy
The rate of fuel consumption depends on many factors: to become lost.
condition of the engine, propeller/rotor pitch, propeller/rotor
revolutions per minute (rpm), richness of the mixture, and Roads shown on the chart are primarily the well-traveled
particularly the percentage of horsepower used for flight roads or those most apparent when viewed from the air.
at cruising speed. The pilot should know the approximate New roads and structures are constantly being built, and
consumption rate from cruise performance charts, or from may not be shown on the chart until the next chart is issued.
experience. In addition to the amount of fuel required for the Some structures, such as antennas may be difficult to see.
flight, there should be sufficient fuel for reserve. Sometimes TV antennas are grouped together in an area near
a town. They are supported by almost invisible guy wires.
Flight Computers Never approach an area of antennas less than 500 feet above
Up to this point, only mathematical formulas have been the tallest one. Most of the taller structures are marked with
used to determine such items as time, distance, speed, and strobe lights to make them more visible to a pilot. However,
fuel consumption. In reality, most pilots use a mechanical some weather conditions or background lighting may make
or electronic flight computer. These devices can compute them difficult to see. Aeronautical charts display the best
numerous problems associated with flight planning and information available at the time of printing, but a pilot should
navigation. The mechanical or electronic computer has an be cautious for new structures or changes that have occurred
instruction book that probably includes sample problems so since the chart was printed.
the pilot can become familiar with its functions and operation.
[Figure 15-18] Dead Reckoning

Plotter Dead reckoning is navigation solely by means of computations
Another aid in flight planning is a plotter, which is a based on time, airspeed, distance, and direction. The products
protractor and ruler. The pilot can use this when determining derived from these variables, when adjusted by wind speed
true course and measuring distance. Most plotters have a ruler and velocity, are heading and GS. The predicted heading takes
which measures in both NM and SM and has a scale for a the aircraft along the intended path and the GS establishes the
sectional chart on one side and a world aeronautical chart on time to arrive at each checkpoint and the destination. Except
the other. [Figure 15-18] for flights over water, dead reckoning is usually used with
pilotage for cross-country flying. The heading and GS as
Pilotage calculated is constantly monitored and corrected by pilotage
as observed from checkpoints.
Pilotage is navigation by reference to landmarks or
checkpoints. It is a method of navigation that can be used The Wind Triangle or Vector Analysis
on any course that has adequate checkpoints, but it is more If there is no wind, the aircraft’s ground track is the same as
commonly used in conjunction with dead reckoning and the heading and the GS is the same as the true airspeed. This
VFR radio navigation. condition rarely exists. A wind triangle, the pilot’s version
of vector analysis, is the basis of dead reckoning.
The checkpoints selected should be prominent features
common to the area of the flight. Choose checkpoints that can The wind triangle is a graphic explanation of the effect of
be readily identified by other features such as roads, rivers, wind upon flight. GS, heading, and time for any flight can be
railroad tracks, lakes, and power lines. If possible, select determined by using the wind triangle. It can be applied to
features that make useful boundaries or brackets on each the simplest kind of cross-country flight as well as the most
side of the course, such as highways, rivers, railroads, and complicated instrument flight. The experienced pilot becomes
mountains. A pilot can keep from drifting too far off course so familiar with the fundamental principles that estimates can
by referring to and not crossing the selected brackets. Never be made which are adequate for visual flight without actually
place complete reliance on any single checkpoint. Choose drawing the diagrams. The beginning student, however, needs

15-12

110 100 90 80 70

130 120 290 280 270 260 250 152040 60 50
310 302010 200 190 180 170 160 230

140 30 20 10 0 350 340 330 40

150 320 220 30 200 190
330 210
DEGREES
170 160 20 10
340

A Plotter 350

NAUTICAL 5 MILES 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 NAUTICAL 85 MILES
30
SECTIONAL CHART SIDE - 1:500,000 INSTRUCTIONS FOR USE NAVIGATIONAL FLIGHT PLOTTER
1. Place hole over intersection of true course and true north line.
2. Without changing position rotate plotter until edge is over true course line. 70 75 80 85 90 95 100
3. From hole follow true north line to curved scale with arrow pointing in direction of flight.
4. Read true course in degrees, on proper scale, over true north line. read scales counter-clockwise.

0 STATUTE 5 MILES 10 15 20 25 35 40 45 50 55 60 65

TSD Alt: As Wind Wt. Bal Timer
Conv: Dist Vol Wt Wx

C
M
P

Mode On/Off Clr
Dist Vol
Wt Wx ÷
:7
Sto 4 89 x
Rcl 1
Bksp 0 56−

23+

. +/- =

C Electronic Flight Computer

B Mechanical Flight Computer

Figure 15-18. A plotter (A), the computational and wind side of a mechanical flight computer (B), and an electronic flight computer
(C).

to develop skill in constructing these diagrams as an aid to the yellow line shows the direction of the track or the path of the
complete understanding of wind effect. Either consciously or aircraft as measured over the earth, and its length represents
unconsciously, every good pilot thinks of the flight in terms the distance traveled in 1 hour, or the GS.
of wind triangle.
In actual practice, the triangle illustrated in Figure 15-19 is
If flight is to be made on a course to the east, with a wind not drawn; instead, construct a similar triangle as shown by
blowing from the northeast, the aircraft must be headed the blue, yellow, and black lines in Figure 15-20, which is
somewhat to the north of east to counteract drift. This can explained in the following example.
be represented by a diagram as shown in Figure 15-19. Each
line represents direction and speed. The long blue and white Suppose a flight is to be flown from E to P. Draw a line on
hashed line shows the direction the aircraft is heading, and the aeronautical chart connecting these two points; measure
its length represents the distance the airspeed for 1 hour. The its direction with a protractor, or plotter, in reference to a
short blue arrow at the right shows the wind direction, and meridian. This is the true course, which in this example is
its length represents the wind velocity for 1 hour. The solid assumed to be 090° (east). From the NWS, it is learned that

15-13

NN 333 080° heading and 120 knots airspeed Wind at 20°
Drift Angle direction and
21 S 1530 W 2412 6 35 knots velocity
E
S
10°
Figure 15-19. Principle of the wind triangle. 090° course and 110 knots groundspeed

N 8° left correction

Wind direction and velocityN 333
12 6
E30 W 24E P

Course and groundspeed

21 S 15

Heading and airspeed

WS

Figure 15-20. The wind triangle as is drawn in navigation practice.

the wind at the altitude of the intended flight is 40 knots from Step 3
the northeast (045°). Since the NWS reports the wind speed in
knots, if the true airspeed of the aircraft is 120 knots, there is Next, align the ruler with E and the dot at 45°, and draw the
no need to convert speeds from knots to mph or vice versa. wind arrow from E, not toward 045°, but downwind in the
direction the wind is blowing, making it 40 units long, to
Now, on a plain sheet of paper draw a vertical line correspond with the wind velocity of 40 knots. Identify this
representing north to south. (The various steps are shown line as the wind line by placing the letter “W” at the end to
in Figure 15-21.) show the wind direction.

Step 1 Step 4
Place the protractor with the base resting on the vertical line
and the curved edge facing east. At the center point of the Finally, measure 120 units on the ruler to represent the
base, make a dot labeled “E” (point of departure), and at the airspeed, making a dot on the ruler at this point. The units
curved edge, make a dot at 90° (indicating the direction of the used may be of any convenient scale or value (such as ¼ inch
true course) and another at 45° (indicating wind direction). = 10 knots), but once selected, the same scale must be used
for each of the linear movements involved. Then place the
Step 2 ruler so that the end is on the arrowhead (W) and the 120-
With the ruler, draw the true course line from E, extending knot dot intercepts the true course line. Draw the line and
it somewhat beyond the dot by 90°, and labeling it “TC label it “AS 120.” The point “P” placed at the intersection
090°.” represents the position of the aircraft at the end of 1 hour.
The diagram is now complete.

15-14

STEP 1 N 45° N STEP 2 and 3
Mid Point
10 20 40
30
40 90°
0 90 10
50 E TC 090°

70 80 90 100 110 Wind
60 120
50 130 WS

160 170
150
140

N 33 3

30 W 24 E 12 6 TC 090° GS 88 P
E
21 S 15 Airspeed 120 knots

W S STEP 4

Figure 15-21. Steps in drawing the wind triangle. • By placing the straight side of the protractor along
the true course line, with its center at P, read the angle
The distance flown in 1 hour (GS) is measured as the numbers between the true course and the airspeed line. This is
of units on the true course line (88 NMPH, or 88 knots). the WCA, which must be applied to the true course
The true heading necessary to offset drift is indicated by the to obtain the true heading. If the wind blows from the
direction of the airspeed line, which can be determined in right of true course, the angle is added; if from the
one of two ways: left, it is subtracted. In the example given, the WCA
is 14° and the wind is from the left; therefore, subtract
• By placing the straight side of the protractor along the 14° from true course of 090°, making the true heading
north-south line, with its center point at the intersection 076°. [Figure 15-23]
of the airspeed line and north-south line, read the true
heading directly in degrees (076°). [Figure 15-22]

N

E TC 090° GS 88 P
76° TH 076° AS 120
10 20
30
40

70 80

70 80 90 100 110
60 120
50 130
W
160 170
S150
Figure 15-22. Finding true heading by the wind correction angle.140

15-15

N

TC 090° GS 88 20 10 P 10 20
E 160 170 30
150 40
WCA =14° L 140

TH 076° AS 120 14° 70 80 90 100 110
60 120
50 130

W

S

Figure 15-23. Finding true heading by direct measurement. • Compass heading—reading on the compass (found by
applying deviation to MH) which is followed to make
After obtaining the true heading, apply the correction for good the desired course.
magnetic variation to obtain magnetic heading, and the
correction for compass deviation to obtain a compass • Total distance—obtained by measuring the length of
heading. The compass heading can be used to fly to the the TC line on the chart (using the scale at the bottom
destination by dead reckoning. of the chart).

To determine the time and fuel required for the flight, first • GS—obtained by measuring the length of the TC line
find the distance to destination by measuring the length of on the wind triangle (using the scale employed for
the course line drawn on the aeronautical chart (using the drawing the diagram).
appropriate scale at the bottom of the chart). If the distance
measures 220 NM, divide by the GS of 88 knots, which gives • Estimated time en route (ETE)—total distance divided
2.5 hours, or 2:30, as the time required. If fuel consumption by GS.
is 8 gallons an hour, 8 x 2.5 or about 20 gallons is used.
Briefly summarized, the steps in obtaining flight information • Fuel rate—predetermined gallons per hour used at
are as follows: cruising speed.

• TC—direction of the line connecting two desired NOTE: Additional fuel for adequate reserve should be added
points, drawn on the chart and measured clockwise as a safety measure.
in degrees from true north on the mid-meridian.
Flight Planning
• WCA—determined from the wind triangle. (Added
to TC if the wind is from the right; subtracted if wind Title 14 of the Code of Federal Regulations (14 CFR) part
is from the left). 91 states, in part, that before beginning a flight, the pilot in
command (PIC) of an aircraft shall become familiar with all
• TH—direction measured in degrees clockwise from available information concerning that flight. For flights not
true north, in which the nose of the plane should point in the vicinity of an airport, this must include information
to make good the desired course. on available current weather reports and forecasts, fuel
requirements, alternatives available if the planned flight
• Variation—obtained from the isogonic line on the chart cannot be completed, and any known traffic delays of which
(added to TH if west; subtracted if east). the pilot in command has been advised by ATC.

• MH—an intermediate step in the conversion (obtained Assembling Necessary Material
by applying variation to true heading). The pilot should collect the necessary material well before the
flight. An appropriate current sectional chart and charts for
• Deviation—obtained from the deviation card on
the aircraft (added to MH or subtracted from, as
indicated).

15-16

areas adjoining the flight route should be among this material The sectional chart bulletin subsection should be checked for
if the route of flight is near the border of a chart. major changes that have occurred since the last publication
date of each sectional chart being used. Remember, the
Additional equipment should include a flight computer or chart may be up to 6 months old. The effective date of the
electronic calculator, plotter, and any other item appropriate chart appears at the top of the front of the chart. The A/FD
to the particular flight. For example, if a night flight is to generally has the latest information pertaining to such matters
be undertaken, carry a flashlight; if a flight is over desert and should be used in preference to the information on the
country, carry a supply of water and other necessities. back of the chart, if there are differences.

Weather Check Airplane Flight Manual or Pilot’s Operating
It is wise to check the weather before continuing with other Handbook (AFM/POH)
aspects of flight planning to see, first of all, if the flight is The Aircraft Flight Manual or Pilot’s Operating Handbook
feasible and, if it is, which route is best. Chapter 12, Aviation (AFM/POH) should be checked to determine the proper
Weather Services, discusses obtaining a weather briefing. loading of the aircraft (weight and balance data). The weight
of the usable fuel and drainable oil aboard must be known.
Use of Airport/Facility Directory (A/FD) Also, check the weight of the passengers, the weight of all
Study available information about each airport at which a baggage to be carried, and the empty weight of the aircraft to
landing is intended. This should include a study of the Notices be sure that the total weight does not exceed the maximum
to Airmen (NOTAMs) and the A/FD. [Figure 15-24] This allowable. The distribution of the load must be known to tell
includes location, elevation, runway and lighting facilities, if the resulting center of gravity (CG) is within limits. Be
available services, availability of aeronautical advisory sure to use the latest weight and balance information in the
station frequency (UNICOM), types of fuel available (use FAA-approved AFM or other permanent aircraft records, as
to decide on refueling stops), AFSS/FSS located on the appropriate, to obtain empty weight and empty weight CG
airport, control tower and ground control frequencies, traffic information.
information, remarks, and other pertinent information. The
NOTAMs, issued every 28 days, should be checked for Determine the takeoff and landing distances from the
additional information on hazardous conditions or changes appropriate charts, based on the calculated load, elevation
that have been made since issuance of the A/FD. of the airport, and temperature; then compare these distances
with the amount of runway available. Remember, the
heavier the load and the higher the elevation, temperature,
or humidity, the longer the takeoff roll and landing roll and
the lower the rate of climb.

Check the fuel consumption charts to determine the rate of
fuel consumption at the estimated flight altitude and power
settings. Calculate the rate of fuel consumption, and then
compare it with the estimated time for the flight so that
refueling points along the route can be included in the plan.

Charting the Course

Once the weather has been checked and some preliminary
planning done, it is time to chart the course and determine the
data needed to accomplish the flight. The following sections
provide a logical sequence to follow in charting the course,
filling out a flight log, and filing a flight plan. In the following
example, a trip is planned based on the following data and
the sectional chart excerpt in Figure 15-25.

Figure 15-24. Airport/Facility Directory.

15-17

4 Checkpoint R F
EHighest elevation

D Tallest obstruction

3 Checkpoint

2 Checkpoint C Class D Airspace
1 Checkpoint B Class C Airspace

Course line

A Route of flight: Chickasha Airport direct to Guthrie Airport

True airspeed (TAS) . . . . . . . . . . . . . . . . . . . . . 115 knots
Winds aloft . . . . . . . . . . . . . . . . . . . . . . . 360° at 10 knots
Usable fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 gallons
Fuel rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 GPH
Deviation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +2°

Figure 15-25. Sectional chart excerpt.

15-18

Route of flight: Chickasha Airport direct to Guthrie the center of the airport of departure and end at the center of
Airport the destination airport. If the route is direct, the course line
consists of a single straight line. If the route is not direct, it
True airspeed (TAS)........................................115 knots consists of two or more straight line segments. For example,
a VOR station which is off the direct route, but which
Winds aloft...........................................360° at 10 knots makes navigating easier, may be chosen (radio navigation
is discussed later in this chapter).
Usable fuel.....................................................38 gallons
Appropriate checkpoints should be selected along the route
Fuel rate...............................................................8 GPH and noted in some way. These should be easy-to-locate points
such as large towns, large lakes and rivers, or combinations of
Deviation..................................................................+2° recognizable points such as towns with an airport, towns with
a network of highways, and railroads entering and departing.
Steps in Charting the Course Normally, choose only towns indicated by splashes of yellow
The following is a suggested sequence for arriving at on the chart. Do not choose towns represented by a small
the pertinent information for the trip. As information is circle—these may turn out to be only a half-dozen houses. (In
determined, it may be noted as illustrated in the example of isolated areas, however, towns represented by a small circle
a flight log in Figure 15-26. Where calculations are required, can be prominent checkpoints.) For this trip, four checkpoints
the pilot may use a mathematical formula or a manual or have been selected. Checkpoint 1 consists of a tower located
electronic flight computer. If unfamiliar with the use of a east of the course and can be further identified by the highway
manual or electronic computer, it would be advantageous to and railroad track, which almost parallels the course at this
read the operation manual and work several practice problems point. Checkpoint 2 is the obstruction just to the west of the
at this point. course and can be further identified by Will Rogers World

First draw a line from Chickasha Airport (point A) directly
to Guthrie Airport (point F). The course line should begin at

PILOT’S PLANNING SHEET

PLANE IDENTIFICATION N123DB DATE

COURSE TC Wind WCA TH WCA MH DEV CH TOTAL GS TOTAL FUEL TOTAL
R+ L- R+ L- MILES TIME RATE FUEL
From Chickasha Knots From 8 GPH 38 gal
To Guthrie
From 031° 10 360° 3° L 28 7° E 21° +2° 23 53 106 kts 35 min
To

VISUAL FLIGHT LOG

TIME OF NAVIGATION COURSE DISTANCE ELAPSED TIME GS CH REMARKS
DEPARTURE AIDS
TO POINT TCOUPMOUINLATTIVE ESTIMAATCETDUAL ESTIMACATTEUDAL ESTIMACATTEUDAL WEATHER
POINT OF NAVAID FROM 11 NM AIRSPACE ETC.
DEPARTURE IDENT. 6 min
Chickasha Airport FREQ. +5

CHECKPOINT 106 kts 023°
#1
10 NM 6 min 106 kts 023°
CHECKPOINT 10.5 NM 21 NM
#2 13 NM 106 kts 023°
6 min
CHECKPOINT 31.5 NM 106 kts 023°
#3
7 min
CHECKPOINT 44.5 NM
#4

DESTINATION 8.5 NM 5 min
53 NM
Guthrie Airport

Figure 15-26. Pilot’s planning sheet and visual flight log.

15-19

Airport which is directly to the east. Checkpoint 3 is Wiley This is done by following the formula given earlier in this
Post Airport, which the aircraft should fly directly over. chapter. The formula is:
Checkpoint 4 is a private, non-surfaced airport to the west of
the course and can be further identified by the railroad track TC ± WCA = TH ± V = MH ± D = CH
and highway to the east of the course.
The WCA can be determined by using a manual or electronic
The course and areas on either side of the planned route flight computer. Using a wind of 360° at 10 knots, it is
should be checked to determine if there is any type of airspace determined the WCA is 3° left. This is subtracted from the
with which the pilot should be concerned or which has TC making the TH 28°. Next, the pilot should locate the
special operational requirements. For this trip, it should be isogonic line closest to the route of the flight to determine
noted that the course passes through a segment of the Class variation. Figure 15-25 shows the variation to be 6.30° E
C airspace surrounding Will Rogers World Airport where the (rounded to 7° E), which means it should be subtracted from
floor of the airspace is 2,500 feet mean sea level (MSL) and the TH, giving an MH of 21°. Next, add 2° to the MH for
the ceiling is 5,300 feet MSL (point B). Also, there is Class the deviation correction. This gives the pilot the compass
D airspace from the surface to 3,800 feet MSL surrounding heading which is 23°.
Wiley Post Airport (point C) during the time the control
tower is in operation. Now, the GS can be determined. This is done using a manual
or electronic calculator. The GS is determined to be 106
Study the terrain and obstructions along the route. This is knots. Based on this information, the total trip time, as well
necessary to determine the highest and lowest elevations as time between checkpoints, and the fuel burned can be
as well as the highest obstruction to be encountered so that determined. These calculations can be done mathematically
an appropriate altitude which conforms to 14 CFR part 91 or by using a manual or electronic calculator.
regulations can be selected. If the flight is to be flown at an
altitude more than 3,000 feet above the terrain, conformance For this trip, the GS is 106 knots and the total time is 35
to the cruising altitude appropriate to the direction of flight minutes (30 minutes plus 5 minutes for climb) with a fuel
is required. Check the route for particularly rugged terrain so burn of 4.7 gallons. Refer to the flight log in Figure 15-26
it can be avoided. Areas where a takeoff or landing is made for the time between checkpoints.
should be carefully checked for tall obstructions. Television
transmitting towers may extend to altitudes over 1,500 feet As the trip progresses, the pilot can note headings and time
above the surrounding terrain. It is essential that pilots be and make adjustments in heading, GS, and time.
aware of their presence and location. For this trip, it should
be noted that the tallest obstruction is part of a series of Filing a VFR Flight Plan
antennas with a height of 2,749 feet MSL (point D). The
highest elevation should be located in the northeast quadrant Filing a flight plan is not required by regulations; however, it
and is 2,900 feet MSL (point E). is a good operating practice, since the information contained
in the flight plan can be used in search and rescue in the event
Since the wind is no factor and it is desirable and within the of an emergency.
aircraft’s capability to fly above the Class C and D airspace
to be encountered, an altitude of 5,500 feet MSL is chosen. Flight plans can be filed in the air by radio, but it is best to
This altitude also gives adequate clearance of all obstructions file a flight plan by phone just before departing. After takeoff,
as well as conforms to the 14 CFR part 91 requirement to contact the AFSS by radio and give them the takeoff time so
fly at an altitude of odd thousand plus 500 feet when on a the flight plan can be activated.
magnetic course between 0 and 179°.
When a VFR flight plan is filed, it is held by the AFSS until
Next, the pilot should measure the total distance of the 1 hour after the proposed departure time and then canceled
course as well as the distance between checkpoints. The total unless: the actual departure time is received; a revised
distance is 53 NM and the distance between checkpoints is proposed departure time is received; or at the time of filing,
as noted on the flight log in Figure 15-26. the AFSS is informed that the proposed departure time is
met, but actual time cannot be given because of inadequate
After determining the distance, the true course should be communication. The FSS specialist who accepts the flight
measured. If using a plotter, follow the directions on the plan does not inform the pilot of this procedure, however.
plotter. The true course is 031°. Once the true heading is
established, the pilot can determine the compass heading.

15-20

Figure 15-27 shows the flight plan form a pilot files with the • Item 10 is the estimated time en route. In the sample
AFSS. When filing a flight plan by telephone or radio, give flight plan, 5 minutes was added to the total time to
the information in the order of the numbered spaces. This allow for the climb.
enables the AFSS specialist to copy the information more
efficiently. Most of the fields are either self-explanatory or • Item 12 is the fuel on board in hours and minutes. This
non-applicable to the VFR flight plan (such as item 13). is determined by dividing the total usable fuel aboard
However, some fields may need explanation. in gallons by the estimated rate of fuel consumption
in gallons.
• Item 3 is the aircraft type and special equipment. An
example would be C-150/X, which means the aircraft Remember, there is every advantage in filing a flight plan;
has no transponder. A listing of special equipment but do not forget to close the flight plan on arrival. Do this
codes is found in the Aeronautical Information Manual by telephone to avoid radio congestion.
(AIM).
Radio Navigation
• Item 6 is the proposed departure time in UTC
(indicated by the “Z”). Advances in navigational radio receivers installed in aircraft,
the development of aeronautical charts which show the exact
• Item 7 is the cruising altitude. Normally, “VFR” can be location of ground transmitting stations and their frequencies,
entered in this block, since the pilot chooses a cruising along with refined flight deck instrumentation make it
altitude to conform to FAA regulations. possible for pilots to navigate with precision to almost any
point desired. Although precision in navigation is obtainable
• Item 8 is the route of flight. If the flight is to be direct, through the proper use of this equipment, beginning pilots
enter the word “direct;” if not, enter the actual route should use this equipment to supplement navigation by visual
to be followed such as via certain towns or navigation reference to the ground (pilotage). This method provides the
aids.

X N123DB C150/X 115 CHK, CHICKASHA

AIRPORT 1400 5500
1
Chickasha direct Guthrie
15-21
GOK, Guthrie Airport 35
Guthrie, OK Jane Smith
Aero Air, Oklahoma City, OK (405) 555-4149
4 45
Red/White McAlester

Figure 15-27. Flight plan form.