A-1

Appendix

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

Time, Fuel, and Distance to Climb at 2,450 Pounds for a Cessna Model 172R
A-3

Cruise Performance for a Cessna Model 172R
A-4

Short Field Landing Distance at 2,450 Pounds for a Cessna Model 172R
A-5

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500

4,219

3,600

5,840

4,940

3,465

3,401

SL

ISA

6,432

5,234

9,400

7,755

4,804

4,535

5,000 ft

ISA +20°C

40,000

35,000

50,000

46,000

30,000

 2:00 4:00 6:00 8:00 9:50

Conditions: 26,985 lb BOW, M 0.74

cruise speed, ISA, zero wind, NBAA 

IFR reserves (200 NM)

Note: Fuel burn figures provided on

top of graph are based on 1,000 lb

payload performance computations.

Range (NM)

Takeoff Field Length (feet) 3,190 6,570 10,230 14,200 18,105 Fuel

Burn (lb)

Time (hour)

Gross Takeoff Weight (lb)

Max

Payload

3,000 lb

Payload

1,000 lb

Payload Zero Payload

Challenger 605 Range/Payload Profile
A-6

0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 

500

1,000

2,000

1,500

2,500

3,500

3,000

4,500

4,000

0

Conditions: 26,985 lb BOW, 1,000 

lb payload, ISA, zero wind, NBAA 

IFR reserves (200 NM)

M0.80 Cruise Speed

M0.74 Cruise Speed

Time (hour)

Distance (NM)

771 NM

3,550 lb

1,685 NM

7,570 lb

730 NM

3,190 lb

1,577 NM

6,570 lb

2,599 NM

11,980 lb

2,424 NM

10,230 lb

3,512 NM

16,820 lb

3,272 NM

14,200 lb

3,700 NM

18,105 lb

CHALLENGER 605 TIME AND FUEL VERSUS DISTANCE

M0.80 Cruise Speed Time 0:00 2:00 4:00 6:00 8:00 8:25

Distance (NM) 0 771 1,685 2,599 3,512 3,701

Fuel (lb) 0 3,550 7,570 11,980 16,820 18,105

M0.74 Cruise Speed Time 0:00 2:00 4:00 6:00 8:00 9:50

Distance (NM) 0 730 1,577 2,424 3,272 4,045

Fuel (lb) 0 3,190 6,570 10,230 14,200 18,105

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

Note: All Challenger 605 performance data are for discussion purposes only. By this document, Bombardier Inc., 

does not intend to make, and is not making, any offer, commitment, representation or warranty of any kind whatsoever. 

All data are subject to change without prior notice. 

4,045 NM

18,105 lb

Challenger 605 Time and Fuel Versus Distance
A-7

420 430 440 450 460 470 480 490

0.160

0.150

0.180

0.170

0.190

0.210

0.200

0.230

0.240

0.220

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

Speed (KTAS)

Specific Range (NM/lb)

CHALLENGER 605 SPECIFIC RANGE

Note: All Challenger 605 performance data are for discussion purposes only. By this document, Bombardier Inc., 

does not intend to make, and is not making, any offer, commitment, representation or warranty of any kind whatsoever. 

All data are subject to change without prior notice. 

M 0.74 

Cruise Speed

M 0.80 Cruise Speed

M 0.82 Cruise Speed

FL 390

FL 370

FL 350

FL 330

FL 310

Plotting of constant FL lines

Flight Level

M0.82 M0.80 M0.74

290 Speed

Spc Range

310 Speed 481 469 434

Spc Range 0.165 0.178 0.199

330 Speed 477 465 430

Spc Range 0.174 0.188 0.208

350 Speed 473 461 427

Spc Range 0.181 0.197 0.216

370 Speed 470 459 424

Spc Range 0.185 0.204 0.222

390 Speed 459 424

Spc Range 0.205 0.223

Plotting of Long Range Cruise and High Speed Cruise lines

FL290 FL310 FL330 FL350 FL370 FL390

M0.74 "X" 434 430 427 424 424

M0.74 "Y" 0.199 0.208 0.216 0.222 0.223

M0.80 "X" 469 465 461 459 459

M0.80 "Y" 0.178 0.188 0.197 0.204 0.205

M0.82 "X" 481 477 473 470

M0.82 "Y" 0.165 0.174 0.181 0.185

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

Challenger 605 Time and Fuel Versus Distance
A-8
G-1

14 CFR. See Title 14 of the Code of Federal Regulations.

100-hour inspection. An inspection identical in scope to 

an annual inspection. Conducted every 100 hours of flight 

on aircraft of under 12,500 pounds that are used to carry 

passengers for hire.

Absolute accuracy. The ability to determine present position 

in space independently, and is most often used by pilots.

Absolute altitude. The actual distance between an aircraft 

and the terrain over which it is flying.

Absolute pressure. Pressure measured from the reference 

of zero pressure, or a vacuum.

A.C. Alternating current.

Acceleration. Force involved in overcoming inertia, and 

which may be defined as a change in velocity per unit of 

time.

Acceleration error. A magnetic compass error apparent when 

the aircraft accelerates while flying on an easterly or westerly 

heading, causing the compass card to rotate toward North.

Accelerate-go distance. The distance required to accelerate 

to V1 with all engines at takeoff power, experience an engine 

failure at V1, and continue the takeoff on the remaining 

engine(s). The runway required includes the distance 

required to climb to 35 feet by which time V2 speed must 

be attained.

Accelerate-stop distance. The distance required to accelerate 

to V1 with all engines at takeoff power, experience an engine 

failure at V1, and abort the takeoff and bring the airplane to 

a stop using braking action only (use of thrust reversing is 

not considered).

Accelerometer. A part of an inertial navigation system 

(INS) that accurately measures the force of acceleration in 

one direction.

ADC. See air data computer.

Glossary

ADF. See automatic direction finder.

ADI. See attitude director indicator.

Adiabatic cooling. A process of cooling the air through 

expansion. For example, as air moves up slope it expands 

with the reduction of atmospheric pressure and cools as it 

expands.

Adiabatic heating. A process of heating dry air through 

compression. For example, as air moves down a slope it is 

compressed, which results in an increase in temperature.

Adjustable-pitch propeller. A propeller with blades whose 

pitch can be adjusted on the ground with the engine not 

running, but which cannot be adjusted in flight. Also referred 

to as a ground adjustable propeller. Sometimes also used 

to refer to constant-speed propellers that are adjustable in 

flight.

Adjustable stabilizer. A stabilizer that can be adjusted in 

flight to trim the airplane, thereby allowing the airplane to 

fly hands-off at any given airspeed.

ADM. See aeronautical decision-making.

ADS-B. See automatic dependent surveillance-broadcast.

Advection fog. Fog resulting from the movement of warm, 

humid air over a cold surface.

Adverse yaw. A condition of flight in which the nose of an 

airplane tends to yaw toward the outside of the turn. This is 

caused by the higher induced drag on the outside wing, which 

is also producing more lift. Induced drag is a by-product of 

the lift associated with the outside wing.

Aerodynamics. The science of the action of air on an object, 

and with the motion of air on other gases. Aerodynamics 

deals with the production of lift by the aircraft, the relative 

wind, and the atmosphere.
G-2

Aeronautical chart. A map used in air navigation containing 

all or part of the following: topographic features, hazards and 

obstructions, navigation aids, navigation routes, designated

airspace, and airports.

Aeronautical decision-making (ADM). A systematic 

approach to the mental process used by pilots to consistently 

determine the best course of action in response to a given 

set of circumstances.

A/FD. See Airport/Facility Directory.

Agonic line. An irregular imaginary line across the surface of 

the Earth along which the magnetic and geographic poles are in 

alignment, and along which there is no magnetic variation.

Ailerons. Primary flight control surfaces mounted on the 

trailing edge of an airplane wing, near the tip. Ailerons control 

roll about the longitudinal axis.

Aircraft. A device that is used, or intended to be used, for 

flight.

Aircraft altitude. The actual height above sea level at which 

the aircraft is flying.

Aircraft approach category. A performance grouping of 

aircraft based on a speed of 1.3 times the stall speed in the 

landing configuration at maximum gross landing weight.

Air data computer (ADC). An aircraft computer that 

receives and processes pitot pressure, static pressure, and 

temperature to calculate very precise altitude, indicated 

airspeed, true airspeed, and air temperature.

Airfoil. Any surface, such as a wing, propeller, rudder, or 

even a trim tab, which provides aerodynamic force when it 

interacts with a moving stream of air.

Air mass. An extensive body of air having fairly uniform 

properties of temperature and moisture.

AIRMET. Inflight weather advisory issued as an amendment 

to the area forecast, concerning weather phenomena of 

operational interest to all aircraft and that is potentially 

hazardous to aircraft with limited capability due to lack of 

equipment, instrumentation, or pilot qualifications.

Airplane. An engine-driven, fixed-wing aircraft heavier than 

air that is supported in flight by the dynamic reaction of air 

against its wings.

Airplane Flight Manual (AFM). A document developed 

by the airplane manufacturer and approved by the Federal 

Aviation Administration (FAA). It is specific to a particular 

make and model airplane by serial number and it contains 

operating procedures and limitations.

Airplane Owner/Information Manual. A document 

developed by the airplane manufacturer containing general 

information about the make and model of an airplane. The 

airplane owner’s manual is not FAA approved and is not 

specific to a particular serial numbered airplane. This manual 

is not kept current, and therefore cannot be substituted for 

the AFM/POH.

Airport diagram. The section of an instrument approach 

procedure chart that shows a detailed diagram of the 

airport. This diagram includes surface features and airport 

configuration information.

Airport/Facility Directory (A/FD). An FAA publication 

containing information on all airports, communications, 

and NAVAIDs.

Airport surface detection equipment (ASDE). Radar 

equipment specifically designed to detect all principal 

features and traffic on the surface of an airport, presenting the 

entire image on the control tower console; used to augment 

visual observation by tower personnel of aircraft and/or 

vehicular movements on runways and taxiways.

Airport surveillance radar (ASR). Approach control 

radar used to detect and display an aircraft’s position in the 

terminal area.

Airport surveillance radar approach. An instrument 

approach in which ATC issues instructions for pilot 

compliance based on aircraft position in relation to the final 

approach course and the distance from the end of the runway 

as displayed on the controller’s radar scope.

Air route surveillance radar (ARSR). Air route traffic 

control center (ARTCC) radar used primarily to detect 

and display an aircraft’s position while en route between 

terminal areas.

Air route traffic control center (ARTCC). Provides ATC 

service to aircraft operating on IFR flight plans within 

controlled airspace and principally during the en route phase 

of flight.

Airspeed. Rate of the aircraft’s progress through the air.
G-3

Airspeed indicator. A differential pressure gauge that 

measures the dynamic pressure of the air through which the 

aircraft is flying. Displays the craft’s airspeed, typically in 

knots, to the pilot.

Air traffic control radar beacon system (ATCRBS). 

Sometimes called secondary surveillance radar (SSR), which 

utilizes a transponder in the aircraft. The ground equipment is 

an interrogating unit, in which the beacon antenna is mounted 

so it rotates with the surveillance antenna. The interrogating 

unit transmits a coded pulse sequence that actuates the aircraft 

transponder. The transponder answers the coded sequence by 

transmitting a preselected coded sequence back to the ground 

equipment, providing a strong return signal and positive 

aircraft identification, as well as other special data.

Airway. An airway is based on a centerline that extends from 

one navigation aid or intersection to another navigation aid 

(or through several navigation aids or intersections); used 

to establish a known route for en route procedures between 

terminal areas.

Airworthiness Certificate. A certificate issued by the FAA 

to all aircraft that have been proven to meet the minimum 

standards set down by the Code of Federal Regulations.

Airworthiness Directive. A regulatory notice sent out by 

the FAA to the registered owner of an aircraft informing the 

owner of a condition that prevents the aircraft from continuing 

to meet its conditions for airworthiness. Airworthiness 

Directives (AD notes) are to be complied with within the 

required time limit, and the fact of compliance, the date of 

compliance, and the method of compliance are recorded in 

the aircraft’s maintenance records.

Alert area. An area in which there is a high volume of pilot 

training or an unusual type of aeronautical activity.

Almanac data. Information the global positioning system 

(GPS) receiver can obtain from one satellite which describes 

the approximate orbital positioning of all satellites in the 

constellation. This information is necessary for the GPS 

receiver to know what satellites to look for in the sky at a 

given time.

ALS. See approach lighting system.

Alternate airport. An airport designated in an IFR flight 

plan, providing a suitable destination if a landing at the 

intended airport becomes inadvisable. 

Alternate static source valve. A valve in the instrument static 

air system that supplies reference air pressure to the altimeter, 

airspeed indicator, and vertical speed indicator if the normal 

static pickup should become clogged or iced over. 

Altimeter. A flight instrument that indicates altitude by 

sensing pressure changes.

Altimeter setting. Station pressure (the barometric pressure 

at the location the reading is taken) which has been corrected 

for the height of the station above sea level.

Altitude engine. A reciprocating aircraft engine having a 

rated takeoff power that is producible from sea level to an 

established higher altitude.

Ambient pressure. The pressure in the area immediately 

surrounding the aircraft.

Ambient temperature. The temperature in the area 

immediately surrounding the aircraft.

AME. See aviation medical examiner.

Amendment status. The circulation date and revision 

number of an instrument approach procedure, printed above 

the procedure identification.

Ammeter. An instrument installed in series with an electrical 

load used to measure the amount of current flowing through 

the load.

Aneroid. The sensitive component in an altimeter or 

barometer that measures the absolute pressure of the air. 

It is a sealed, flat capsule made of thin disks of corrugated 

metal soldered together and evacuated by pumping all of 

the air out of it.

Aneroid barometer. An instrument that measures the 

absolute pressure of the atmosphere by balancing the weight 

of the air above it against the spring action of the aneroid.

Angle of attack. The acute angle formed between the 

chord line of an airfoil and the direction of the air striking 

the airfoil.

Angle of incidence. The angle formed by the chord line of 

the wing and a line parallel to the longitudinal axis of the 

airplane.
G-4

Anhedral. A downward slant from root to tip of an aircraft’s 

wing or horizontal tail surface.

Annual inspection. A complete inspection of an aircraft and 

engine, required by the Code of Federal Regulations, to be 

accomplished every 12 calendar months on all certificated 

aircraft. Only an A&P technician holding an Inspection 

Authorization can conduct an annual inspection.

Anti-ice. Preventing the accumulation of ice on an aircraft 

structure via a system designed for that purpose.

Antiservo tab. An adjustable tab attached to the trailing edge 

of a stabilator that moves in the same direction as the primary 

control. It is used to make the stabilator less sensitive.

Approach lighting system (ALS). Provides lights that will 

penetrate the atmosphere far enough from touchdown to 

give directional, distance, and glidepath information for safe 

transition from instrument to visual flight.

Area chart. Part of the low-altitude en route chart series, 

this chart furnishes terminal data at a larger scale for 

congested areas.

Area forecast (FA). A report that gives a picture of clouds, 

general weather conditions, and visual meteorological 

conditions (VMC) expected over a large area encompassing 

several states.

Area navigation (RNAV). Allows a pilot to fly a selected 

course to a predetermined point without the need to overfly 

ground-based navigation facilities, by using waypoints.

Arm. See moment arm.

ARSR. See air route surveillance radar.

ARTCC. See air route traffic control center.

ASDE. See airport surface detection equipment.

ASOS. See Automated Surface Observing System.

Aspect ratio. Span of a wing divided by its average chord.

ASR. See airport surveillance radar.

Asymmetric thrust. Also known as P-factor. A tendency for 

an aircraft to yaw to the left due to the descending propeller 

blade on the right producing more thrust than the ascending 

blade on the left. This occurs when the aircraft’s longitudinal 

axis is in a climbing attitude in relation to the relative wind. 

The P-factor would be to the right if the aircraft had a 

counterclockwise rotating propeller.

ATC. Air Traffic Control.

ATCRBS. See air traffic control radar beacon system.

ATIS. See automatic terminal information service. 

Atmospheric propagation delay. A bending of the 

electromagnetic (EM) wave from the satellite that creates 

an error in the GPS system.

Attitude. A personal motivational predisposition to respond 

to persons, situations, or events in a given manner that can, 

nevertheless, be changed or modified through training as sort 

of a mental shortcut to decision-making.

Attitude and heading reference system (AHRS). A system 

composed of three-axis sensors that provide heading, attitude, 

and yaw information for aircraft. AHRS are designed to 

replace traditional mechanical gyroscopic flight instruments 

and provide superior reliability and accuracy.

Attitude director indicator (ADI). An aircraft attitude 

indicator that incorporates flight command bars to provide 

pitch and roll commands.

Attitude indicator. The foundation for all instrument flight, 

this instrument reflects the airplane’s attitude in relation to 

the horizon.

Attitude instrument flying. Controlling the aircraft by 

reference to the instruments rather than by outside visual 

cues.

Attitude management. The ability to recognize hazardous 

attitudes in oneself and the willingness to modify them as 

necessary through the application of an appropriate antidote 

thought.

Autokinesis. Nighttime visual illusion that a stationary light 

is moving, which becomes apparent after several seconds of 

staring at the light.

Automated Surface Observing System (ASOS). Weather 

reporting system which provides surface observations every 

minute via digitized voice broadcasts and printed reports.

Automated Weather Observing System (AWOS). 

Automated weather reporting system consisting of various 

sensors, a processor, a computer-generated voice subsystem, 

and a transmitter to broadcast weather data.
G-5

Automatic dependent surveillance—broadcast (ADSB). A device used in aircraft that repeatedly broadcasts a 

message that includes position (such as latitude, longitude, 

and altitude), velocity, and possibly other information. 

Automatic direction finder (ADF). Electronic navigation 

equipment that operates in the low- and medium-frequency 

bands. Used in conjunction with the ground-based 

nondirectional beacon (NDB), the instrument displays the 

number of degrees clockwise from the nose of the aircraft 

to the station being received. 

Automatic terminal information service (ATIS). The 

continuous broadcast of recorded non-control information in 

selected terminal areas. Its purpose is to improve controller 

effectiveness and relieve frequency congestion by automating 

repetitive transmission of essential but routine information.

Autopilot. An automatic flight control system which keeps 

an aircraft in level flight or on a set course. Automatic pilots 

can be directed by the pilot, or they may be coupled to a 

radio navigation signal.

Aviation medical examiner (AME). A physician with 

training in aviation medicine designated by the Civil 

Aerospace Medical Institute (CAMI).

Aviation Routine Weather Report (METAR). Observation 

of current surface weather reported in a standard international 

format.

AWOS. See Automated Weather Observing System.

Axes of an aircraft. Three imaginary lines that pass through 

an aircraft’s center of gravity. The axes can be considered 

as imaginary axles around which the aircraft rotates. The 

three axes pass through the center of gravity at 90° angles to 

each other. The axis from nose to tail is the longitudinal axis 

(pitch), the axis that passes from wingtip to wingtip is the 

lateral axis (roll), and the axis that passes vertically through 

the center of gravity is the vertical axis (yaw).

Axial flow compressor. A type of compressor used in a 

turbine engine in which the airflow through the compressor 

is essentially linear. An axial-flow compressor is made up of 

several stages of alternate rotors and stators. The compressor 

ratio is determined by the decrease in area of the succeeding 

stages.

Azimuth card. A card that may be set, gyroscopically 

controlled, or driven by a remote compass.

Back course (BC). The reciprocal of the localizer course 

for an ILS. When flying a back-course approach, an aircraft 

approaches the instrument runway from the end at which the 

localizer antennas are installed.

Balance tab. An auxiliary control mounted on a primary 

control surface, which automatically moves in the direction 

opposite the primary control to provide an aerodynamic 

assist in the movement of the control. Sometimes referred 

to as a servo tab.

Baro-aiding. A method of augmenting the GPS integrity 

solution by using a nonsatellite input source. To ensure that 

baro-aiding is available, the current altimeter setting must 

be entered as described in the operating manual.

Barometric scale. A scale on the dial of an altimeter to which 

the pilot sets the barometric pressure level from which the 

altitude shown by the pointers is measured.

Basic empty weight (GAMA). Basic empty weight 

includes the standard empty weight plus optional and special 

equipment that has been installed.

BC. See back course.

Bernoulli’s Principle. A principle that explains how the 

pressure of a moving fluid varies with its speed of motion. 

An increase in the speed of movement causes a decrease in 

the fluid’s pressure.

Biplanes. Airplanes with two sets of wings.

Block altitude. A block of altitudes assigned by ATC to 

allow altitude deviations; for example, “Maintain block 

altitude 9 to 11 thousand.”

Bypass ratio. The ratio of the mass airflow in pounds per 

second through the fan section of a turbofan engine to the 

mass airflow that passes through the gas generator portion 

of the engine.

Cabin altitude. Cabin pressure in terms of equivalent altitude 

above sea level.

Cage. The black markings on the ball instrument indicating 

its neutral position.

Calibrated. The instrument indication compared with a 

standard value to determine the accuracy of the instrument.
G-6

Calibrated orifice. A hole of specific diameter used to delay 

the pressure change in the case of a vertical speed indicator.

Calibrated airspeed. The speed at which the aircraft 

is moving through the air, found by correcting IAS for 

instrument and position errors.

Camber. The camber of an airfoil is the characteristic curve 

of its upper and lower surfaces. The upper camber is more 

pronounced, while the lower camber is comparatively flat. 

This causes the velocity of the airflow immediately above the 

wing to be much higher than that below the wing.

Canard. A horizontal surface mounted ahead of the main 

wing to provide longitudinal stability and control. It may 

be a fixed, movable, or variable geometry surface, with or 

without control surfaces.

Canard configuration. A configuration in which the span 

of the forward wings is substantially less than that of the 

main wing.

Cantilever. A wing designed to carry loads without external 

struts.

CAS. Calibrated airspeed.

CDI. Course deviation indicator.

Ceiling. The height above the earth’s surface of the lowest 

layer of clouds, which is reported as broken or overcast, or 

the vertical visibility into an obscuration.

Center of gravity (CG). The point at which an airplane 

would balance if it were possible to suspend it at that point. 

It is the mass center of the airplane, or the theoretical point 

at which the entire weight of the airplane is assumed to 

be concentrated. It may be expressed in inches from the 

reference datum, or in percentage of mean aerodynamic 

chord (MAC). The location depends on the distribution of 

weight in the airplane.

Center of gravity limits. The specified forward and aft points 

within which the CG must be located during flight. These 

limits are indicated on pertinent airplane specifications.

Center of gravity range. The distance between the 

forward and aft CG limits indicated on pertinent airplane 

specifications.

Center of pressure. A point along the wing chord line 

where lift is considered to be concentrated. For this reason, 

the center of pressure is commonly referred to as the center 

of lift.

Centrifugal flow compressor. An impeller-shaped device 

that receives air at its center and slings the air outward at high 

velocity into a diffuser for increased pressure. Also referred 

to as a radial outflow compressor.

Centrifugal force. An outward force, that opposes centripetal 

force, resulting from the effect of inertia during a turn.

Centripetal force. A center-seeking force directed inward 

toward the center of rotation created by the horizontal 

component of lift in turning flight.

CG. See center of gravity.

Changeover point (COP). A point along the route or 

airway segment between two adjacent navigation facilities 

or waypoints where changeover in navigation guidance 

should occur.

Checklist. A tool that is used as a human factors aid in 

aviation safety. It is a systematic and sequential list of all 

operations that must be performed to properly accomplish 

a task.

Chord line. An imaginary straight line drawn through an 

airfoil from the leading edge to the trailing edge.

Circling approach. A maneuver initiated by the pilot to 

align the aircraft with a runway for landing when a straightin landing from an instrument approach is not possible or is 

not desirable.

Class A airspace. Airspace from 18,000 feet MSL up to and 

including FL 600, including the airspace overlying the waters 

within 12 NM of the coast of the 48 contiguous states and 

Alaska; and designated international airspace beyond 12 NM 

of the coast of the 48 contiguous states and Alaska within areas 

of domestic radio navigational signal or ATC radar coverage, 

and within which domestic procedures are applied.

Class B airspace. Airspace from the surface to 10,000 feet 

MSL surrounding the nation’s busiest airports in terms of 

IFR operations or passenger numbers. The configuration of 

each Class B airspace is individually tailored and consists 
G-7

of a surface area and two or more layers, and is designed to 

contain all published instrument procedures once an aircraft 

enters the airspace. For all aircraft, an ATC clearance is 

required to operate in the area, and aircraft so cleared receive 

separation services within the airspace.

Class C airspace. Airspace from the surface to 4,000 feet 

above the airport elevation (charted in MSL) surrounding 

those airports having an operational control tower, serviced 

by radar approach control, and having a certain number of IFR 

operations or passenger numbers. Although the configuration 

of each Class C airspace area is individually tailored, the 

airspace usually consists of a 5 NM radius core surface area 

that extends from the surface up to 4,000 feet above the airport 

elevation, and a 10 NM radius shelf area that extends from 

1,200 feet to 4,000 feet above the airport elevation.

Class D airspace. Airspace from the surface to 2,500 feet 

above the airport elevation (charted in MSL) surrounding 

those airports that have an operational control tower. The 

configuration of each Class D airspace area is individually 

tailored, and when instrument procedures are published, the 

airspace is normally designed to contain the procedures.

Class E airspace. Airspace that is not Class A, Class B, Class 

C, or Class D, and is controlled airspace.

Class G airspace. Airspace that is uncontrolled, except 

when associated with a temporary control tower, and has 

not been designated as Class A, Class B, Class C, Class D, 

or Class E airspace.

Clean configuration. A configuration in which all flight 

control surfaces have been placed to create minimum drag. 

In most aircraft this means flaps and gear retracted.

Clearance. ATC permission for an aircraft to proceed under 

specified traffic conditions within controlled airspace, for the 

purpose of providing separation between known aircraft.

Clearance delivery. Control tower position responsible for 

transmitting departure clearances to IFR flights.

Clearance limit. The fix, point, or location to which an 

aircraft is cleared when issued an air traffic clearance.

Clearance on request. An IFR clearance not yet received 

after filing a flight plan.

Clearance void time. Used by ATC, the time at which the 

departure clearance is automatically canceled if takeoff has 

not been made. The pilot must obtain a new clearance or 

cancel the IFR flight plan if not off by the specified time.

Clear ice. Glossy, clear, or translucent ice formed by the 

relatively slow freezing of large, supercooled water droplets.

Coefficient of lift. The ratio between lift pressure and 

dynamic pressure.

Cold front. The boundary between two air masses where 

cold air is replacing warm air.

Compass course. A true course corrected for variation and 

deviation errors.

Compass locator. A low-power, low- or medium-frequency 

(L/MF) radio beacon installed at the site of the outer or middle 

marker of an ILS.

Compass rose. A small circle graduated in 360° increments, 

to show direction expressed in degrees.

Complex aircraft. An aircraft with retractable landing gear, 

flaps, and a controllable pitch propeller.

Compressor pressure ratio. The ratio of compressor 

discharge pressure to compressor inlet pressure.

Compressor stall. In gas turbine engines, a condition in 

an axial-flow compressor in which one or more stages of 

rotor blades fail to pass air smoothly to the succeeding 

stages. A stall condition is caused by a pressure ratio that is 

incompatible with the engine rpm. Compressor stall will be 

indicated by a rise in exhaust temperature or rpm fluctuation, 

and if allowed to continue, may result in flameout and 

physical damage to the engine.

Computer navigation fix. A point used to define a 

navigation track for an airborne computer system such as 

GPS or FMS.

Concentric rings. Dashed-line circles depicted in the plan 

view of IAP charts, outside of the reference circle, that show 

en route and feeder facilities.

Condensation. A change of state of water from a gas (water 

vapor) to a liquid.

Condensation nuclei. Small particles of solid matter in the 

air on which water vapor condenses.

Cone of confusion. A cone-shaped volume of airspace 

directly above a VOR station where no signal is received, 

causing the CDI to fluctuate.
G-8

Configuration. This is a general term, which normally refers 

to the position of the landing gear and flaps.

Constant-speed propeller. A controllable-pitch propeller 

whose pitch is automatically varied in flight by a governor 

to maintain a constant rpm in spite of varying air loads.

Continuous flow oxygen system. System that supplies 

a constant supply of pure oxygen to a rebreather bag that 

dilutes the pure oxygen with exhaled gases and thus supplies a 

healthy mix of oxygen and ambient air to the mask. Primarily 

used in passenger cabins of commercial airliners.

Control and performance. A method of attitude instrument 

flying in which one instrument is used for making attitude 

changes, and the other instruments are used to monitor the 

progress of the change.

Control display unit. A display interfaced with the master 

computer, providing the pilot with a single control point 

for all navigations systems, thereby reducing the number of 

required flight deck panels.

Controllability. A measure of the response of an aircraft 

relative to the pilot’s flight control inputs.

Controlled airspace. An airspace of defined dimensions 

within which ATC service is provided to IFR and VFR flights 

in accordance with the airspace classification. It includes 

Class A, Class B, Class C, Class D, and Class E airspace.

Control pressures. The amount of physical exertion on the 

control column necessary to achieve the desired attitude.

Convective weather. Unstable, rising air found in 

cumiliform clouds.

Convective SIGMET. Weather advisory concerning 

convective weather significant to the safety of all aircraft, 

including thunderstorms, hail, and tornadoes.

Conventional landing gear. Landing gear employing a third 

rear-mounted wheel. These airplanes are also sometimes 

referred to as tailwheel airplanes.

Coordinated flight. Flight with a minimum disturbance of 

the forces maintaining equilibrium, established via effective 

control use.

COP. See changeover point.

Coriolis illusion. The illusion of rotation or movement in an 

entirely different axis, caused by an abrupt head movement, 

while in a prolonged constant-rate turn that has ceased to 

stimulate the brain’s motion sensing system.

Coupled ailerons and rudder. Rudder and ailerons are 

connected with interconnected springs in order to counteract 

adverse yaw. Can be overridden if it becomes necessary to 

slip the aircraft.

Course. The intended direction of flight in the horizontal 

plane measured in degrees from north.

Cowl flaps. Shutter-like devices arranged around certain 

air-cooled engine cowlings, which may be opened or closed 

to regulate the flow of air around the engine.

Crew resource management (CRM). The application of 

team management concepts in the flight deck environment. 

It was initially known as cockpit resource management, 

but as CRM programs evolved to include cabin crews, 

maintenance personnel, and others, the phrase “crew 

resource management” was adopted. This includes single 

pilots, as in most general aviation aircraft. Pilots of small 

aircraft, as well as crews of larger aircraft, must make 

effective use of all available resources; human resources, 

hardware, and information. A current definition includes 

all groups routinely working with the flight crew who 

are involved in decisions required to operate a flight 

safely. These groups include, but are not limited to pilots, 

dispatchers, cabin crewmembers, maintenance personnel, 

and air traffic controllers. CRM is one way of addressing 

the challenge of optimizing the human/machine interface 

and accompanying interpersonal activities.

Critical altitude. The maximum altitude under standard 

atmospheric conditions at which a turbocharged engine can 

produce its rated horsepower.

Critical angle of attack. The angle of attack at which 

a wing stalls regardless of airspeed, flight attitude, or 

weight.

Critical areas. Areas where disturbances to the ILS localizer 

and glideslope courses may occur when surface vehicles or 

aircraft operate near the localizer or glideslope antennas.

CRM. See crew resource management.
G-9

Cross-check. The first fundamental skill of instrument flight, 

also known as “scan,” the continuous and logical observation 

of instruments for attitude and performance information.

Cruise clearance. An ATC clearance issued to allow a 

pilot to conduct flight at any altitude from the minimum 

IFR altitude up to and including the altitude specified in the 

clearance. Also authorizes a pilot to proceed to and make an 

approach at the destination airport.

Current induction. An electrical current being induced into, 

or generated in, any conductor that is crossed by lines of flux 

from any magnet.

DA. See decision altitude.

Datum (Reference Datum). An imaginary vertical plane 

or line from which all measurements of arm are taken. The 

datum is established by the manufacturer. Once the datum 

has been selected, all moment arms and the location of CG 

range are measured from this point.

D.C. Direct current.

Dark adaptation. Physical and chemical adjustments of the 

eye that make vision possible in relative darkness.

Dead reckoning. Navigation of an airplane solely by means 

of computations based on airspeed, course, heading, wind 

direction and speed, groundspeed, and elapsed time.

Deceleration error. A magnetic compass error that occurs 

when the aircraft decelerates while flying on an easterly 

or westerly heading, causing the compass card to rotate 

toward South.

Decision altitude (DA). A specified altitude in the precision 

approach, charted in feet MSL, at which a missed approach 

must be initiated if the required visual reference to continue 

the approach has not been established.

Decision height (DH). A specified altitude in the precision 

approach, charted in height above threshold elevation, 

at which a decision must be made either to continue the 

approach or to execute a missed approach.

Deice. The act of removing ice accumulation from an 

aircraft structure.

Delta. A Greek letter expressed by the symbol ∆ to indicate 

a change of values. As an example, ∆CG indicates a change 

(or movement) of the CG.

Density altitude. Pressure altitude corrected for nonstandard 

temperature. Density altitude is used in computing the 

performance of an aircraft and its engines.

Departure procedure (DP). Preplanned IFR ATC departure, 

published for pilot use, in textual and graphic format.

Deposition. The direct transformation of a gas to a solid 

state, in which the liquid state is bypassed. Some sources use 

sublimation to describe this process instead of deposition.

Detonation. The sudden release of heat energy from fuel in 

an aircraft engine caused by the fuel-air mixture reaching 

its critical pressure and temperature. Detonation occurs as a 

violent explosion rather than a smooth burning process.

Deviation. A magnetic compass error caused by local 

magnetic fields within the aircraft. Deviation error is different 

on each heading.

Dew. Moisture that has condensed from water vapor. Usually 

found on cooler objects near the ground, such as grass, as 

the near-surface layer of air cools faster than the layers of 

air above it.

Dewpoint. The temperature at which air reaches a state where 

it can hold no more water.

DGPS. Differential global positioning system.

DH. See decision height.

Differential ailerons. Control surface rigged such that the 

aileron moving up moves a greater distance than the aileron 

moving down. The up aileron produces extra parasite drag 

to compensate for the additional induced drag caused by 

the down aileron. This balancing of the drag forces helps 

minimize adverse yaw.

Differential Global Positioning System (DGPS). A system 

that improves the accuracy of Global Navigation Satellite 

Systems (GNSS) by measuring changes in variables to 

provide satellite positioning corrections.

Differential pressure. A difference between two pressures. 

The measurement of airspeed is an example of the use of 

differential pressure.

Dihedral. The positive acute angle between the lateral 

axis of an airplane and a line through the center of a wing 

or horizontal stabilizer. Dihedral contributes to the lateral 

stability of an airplane.
G-10

Diluter-demand oxygen system. An oxygen system that 

delivers oxygen mixed or diluted with air in order to maintain 

a constant oxygen partial pressure as the altitude changes.

Direct indication. The true and instantaneous reflection of 

aircraft pitch-and-bank attitude by the miniature aircraft, 

relative to the horizon bar of the attitude indicator.

Direct User Access Terminal System (DUATS). A system 

that provides current FAA weather and flight plan filing 

services to certified civil pilots, via personal computer, 

modem, or telephone access to the system. Pilots can request 

specific types of weather briefings and other pertinent data 

for planned flights.

Directional stability. Stability about the vertical axis of an 

aircraft, whereby an aircraft tends to return, on its own, to 

flight aligned with the relative wind when disturbed from that 

equilibrium state. The vertical tail is the primary contributor 

to directional stability, causing an airplane in flight to align 

with the relative wind.

Distance circle. See reference circle.

Distance measuring equipment (DME). A pulse-type 

electronic navigation system that shows the pilot, by an 

instrument-panel indication, the number of nautical miles 

between the aircraft and a ground station or waypoint.

DME. See distance measuring equipment.

DME arc. A flight track that is a constant distance from the 

station or waypoint.

DOD. Department of Defense.

Doghouse. A turn-and-slip indicator dial mark in the shape 

of a doghouse.

Domestic Reduced Vertical Separation Minimum 

(DRVSM). Additional flight levels between FL 290 and FL 

410 to provide operational, traffic, and airspace efficiency.

Double gimbal. A type of mount used for the gyro in an 

attitude instrument. The axes of the two gimbals are at right 

angles to the spin axis of the gyro, allowing free motion in 

two planes around the gyro.

DP. See departure procedure.

Drag. The net aerodynamic force parallel to the relative 

wind, usually the sum of two components: induced drag 

and parasite drag.

Drag curve. The curve created when plotting induced drag 

and parasite drag.

Drift angle. Angle between heading and track.

DRVSM. See Domestic Reduced Vertical Separation 

Minimum.

DUATS. See direct user access terminal system.

Duplex. Transmitting on one frequency and receiving on a 

separate frequency.

Dutch roll. A combination of rolling and yawing oscillations 

that normally occurs when the dihedral effects of an aircraft 

are more powerful than the directional stability. Usually 

dynamically stable but objectionable in an airplane because 

of the oscillatory nature.

Dynamic hydroplaning. A condition that exists when 

landing on a surface with standing water deeper than the 

tread depth of the tires. When the brakes are applied, there is 

a possibility that the brake will lock up and the tire will ride 

on the surface of the water, much like a water ski. When the 

tires are hydroplaning, directional control and braking action 

are virtually impossible. An effective anti-skid system can 

minimize the effects of hydroplaning.

Dynamic stability. The property of an aircraft that causes 

it, when disturbed from straight-and-level flight, to develop 

forces or moments that restore the original condition of 

straight and level.

Eddy currents. Current induced in a metal cup or disc when 

it is crossed by lines of flux from a moving magnet.

Eddy current damping. The decreased amplitude of 

oscillations by the interaction of magnetic fields. In the case 

of a vertical card magnetic compass, flux from the oscillating 

permanent magnet produces eddy currents in a damping disk 

or cup. The magnetic flux produced by the eddy currents 

opposes the flux from the permanent magnet and decreases 

the oscillations.

EFAS. See En Route Flight Advisory Service.

EFC. See expect-further-clearance.

EFD. See electronic flight display.

EGT. See exhaust gas temperature.
G-11

Electronic flight display (EFD). For the purpose of 

standardization, any flight instrument display that uses LCD 

or other image-producing system (cathode ray tube (CRT), 

etc.)

Elevator. The horizontal, movable primary control surface 

in the tail section, or empennage, of an airplane. The 

elevator is hinged to the trailing edge of the fixed horizontal 

stabilizer.

Elevator illusion. The sensation of being in a climb or 

descent, caused by the kind of abrupt vertical accelerations 

that result from up- or downdrafts.

Emergency. A distress or urgent condition.

Empennage. The section of the airplane that consists of the 

vertical stabilizer, the horizontal stabilizer, and the associated 

control surfaces.

Emphasis error. The result of giving too much attention 

to a particular instrument during the cross-check, instead of 

relying on a combination of instruments necessary for attitude 

and performance information.

Empty-field myopia. Induced nearsightedness that is 

associated with flying at night, in instrument meteorological 

conditions and/or reduced visibility. With nothing to focus 

on, the eyes automatically focus on a point just slightly ahead 

of the airplane.

EM wave. Electromagnetic wave.

Encoding altimeter. A special type of pressure altimeter 

used to send a signal to the air traffic controller on the ground, 

showing the pressure altitude the aircraft is flying.

Engine pressure ratio (EPR). The ratio of turbine discharge 

pressure divided by compressor inlet pressure, which is used 

as an indication of the amount of thrust being developed by 

a turbine engine.

En route facilities ring. Depicted in the plan view of IAP 

charts, a circle which designates NAVAIDs, fixes, and 

intersections that are part of the en route low altitude airway 

structure.

En Route Flight Advisory Service (EFAS). An en route 

weather-only AFSS service.

En route high-altitude charts. Aeronautical charts for en 

route instrument navigation at or above 18,000 feet MSL.

En route low-altitude charts. Aeronautical charts for en 

route IFR navigation below 18,000 feet MSL.

EPR. See engine pressure ratio.

Equilibrium. A condition that exists within a body when the 

sum of the moments of all of the forces acting on the body 

is equal to zero. In aerodynamics, equilibrium is when all 

opposing forces acting on an aircraft are balanced (steady, 

unaccelerated flight conditions).

Equivalent airspeed. Airspeed equivalent to CAS in 

standard atmosphere at sea level. As the airspeed and pressure 

altitude increase, the CAS becomes higher than it should be, 

and a correction for compression must be subtracted from 

the CAS.

Evaporation. The transformation of a liquid to a gaseous 

state, such as the change of water to water vapor.

Exhaust gas temperature (EGT). The temperature of the 

exhaust gases as they leave the cylinders of a reciprocating 

engine or the turbine section of a turbine engine.

Expect-further-clearance (EFC). The time a pilot can 

expect to receive clearance beyond a clearance limit.

Explosive decompression. A change in cabin pressure faster 

than the lungs can decompress. Lung damage is possible.

FA. See area forecast.

FAA. Federal Aviation Administration.

FAF. See final approach fix.

False horizon. Inaccurate visual information for aligning the 

aircraft, caused by various natural and geometric formations 

that disorient the pilot from the actual horizon.

FDI. See flight director indicator.

Federal airways. Class E airspace areas that extend upward 

from 1,200 feet to, but not including, 18,000 feet MSL, unless 

otherwise specified.

Feeder facilities. Used by ATC to direct aircraft to 

intervening fixes between the en route structure and the 

initial approach fix.

Final approach. Part of an instrument approach 

procedure in which alignment and descent for landing are 

accomplished. 
G-12

Final approach fix (FAF). The fix from which the IFR 

final approach to an airport is executed, and which identifies 

the beginning of the final approach segment. An FAF is 

designated on government charts by a Maltese cross symbol 

for nonprecision approaches, and a lightning bolt symbol for 

precision approaches.

Fixating. Staring at a single instrument, thereby interrupting 

the cross-check process.

Fixed-pitch propellers. Propellers with fixed blade angles. 

Fixed-pitch propellers are designed as climb propellers, 

cruise propellers, or standard propellers.

Fixed slot. A fixed, nozzle shaped opening near the leading 

edge of a wing that ducts air onto the top surface of the wing. 

Its purpose is to increase lift at higher angles of attack.

FL. See flight level.

Flameout. A condition in the operation of a gas turbine 

engine in which the fire in the engine goes out due to either 

too much or too little fuel sprayed into the combustors.

Flaps. Hinged portion of the trailing edge between the 

ailerons and fuselage. In some aircraft ailerons and flaps are 

interconnected to produce full-span “flaperons.” In either 

case, flaps change the lift and drag on the wing.

Floor load limit. The maximum weight the floor can sustain 

per square inch/foot as provided by the manufacturer.

Flight configurations. Adjusting the aircraft control surfaces 

(including flaps and landing gear) in a manner that will 

achieve a specified attitude.

Flight director indicator (FDI). One of the major components 

of a flight director system, it provides steering commands that 

the pilot (or the autopilot, if coupled) follows.

Flight level (FL). A measure of altitude (in hundreds of feet) 

used by aircraft flying above 18,000 feet with the altimeter 

set at 29.92 "Hg.

Flight management system (FMS). Provides pilot and crew 

with highly accurate and automatic long-range navigation 

capability, blending available inputs from long- and shortrange sensors.

Flight path. The line, course, or track along which an aircraft 

is flying or is intended to be flown.

Flight patterns. Basic maneuvers, flown by reference to the 

instruments rather than outside visual cues, for the purpose 

of practicing basic attitude flying. The patterns simulate 

maneuvers encountered on instrument flights such as holding 

patterns, procedure turns, and approaches.

Flight strips. Paper strips containing instrument flight 

information, used by ATC when processing flight plans.

FMS. See flight management system.

FOD. See foreign object damage.

Fog. Cloud consisting of numerous minute water droplets 

and based at the surface; droplets are small enough to be 

suspended in the earth’s atmosphere indefinitely. (Unlike 

drizzle, it does not fall to the surface. Fog differs from a 

cloud only in that a cloud is not based at the surface, and is 

distinguished from haze by its wetness and gray color.)

Force (F). The energy applied to an object that attempts to 

cause the object to change its direction, speed, or motion. 

In aerodynamics, it is expressed as F, T (thrust), L (lift), W 

(weight), or D (drag), usually in pounds.

Foreign object damage (FOD). Damage to a gas turbine 

engine caused by some object being sucked into the engine 

while it is running. Debris from runways or taxiways can 

cause foreign object damage during ground operations, and 

the ingestion of ice and birds can cause FOD in flight.

Form drag. The drag created because of the shape of a 

component or the aircraft.

Frise-type aileron. Aileron having the nose portion 

projecting ahead of the hinge line. When the trailing edge 

of the aileron moves up, the nose projects below the wing’s 

lower surface and produces some parasite drag, decreasing 

the amount of adverse yaw.

Front. The boundary between two different air masses.

Frost. Ice crystal deposits formed by sublimation when 

temperature and dewpoint are below freezing.

Fuel load. The expendable part of the load of the airplane. 

It includes only usable fuel, not fuel required to fill the lines 

or that which remains trapped in the tank sumps.

Fundamental skills. Pilot skills of instrument cross-check, 

instrument interpretation, and aircraft control.
G-13

Fuselage. The section of the airplane that consists of the 

cabin and/or cockpit, containing seats for the occupants and 

the controls for the airplane.

GAMA. General Aviation Manufacturers Association.

Gimbal ring. A type of support that allows an object, such 

as a gyroscope, to remain in an upright condition when its 

base is tilted.

Glideslope (GS). Part of the ILS that projects a radio beam 

upward at an angle of approximately 3° from the approach 

end of an instrument runway. The glideslope provides 

vertical guidance to aircraft on the final approach course for 

the aircraft to follow when making an ILS approach along 

the localizer path.

Glideslope intercept altitude. The minimum altitude of an 

intermediate approach segment prescribed for a precision 

approach that ensures obstacle clearance.

Global landing system (GLS). An instrument approach with 

lateral and vertical guidance with integrity limits (similar to 

barometric vertical navigation (BARO VNAV).

Global navigation satellite system (GNSS). Satellite 

navigation system that provides autonomous geospatial 

positioning with global coverage. It allows small electronic 

receivers to determine their location (longitude, latitude, and 

altitude) to within a few meters using time signals transmitted 

along a line of sight by radio from satellites. 

Global positioning system (GPS). Navigation system 

that uses satellite rather than ground-based transmitters for 

location information.

GLS. See global landing system.

GNSS. See global navigation satellite system.

Goniometer. As used in radio frequency (RF) antenna 

systems, a direction-sensing device consisting of two fixed 

loops of wire oriented 90° from each other, which separately 

sense received signal strength and send those signals to two 

rotors (also oriented 90°) in the sealed direction-indicating 

instrument. The rotors are attached to the direction-indicating 

needle of the instrument and rotated by a small motor until 

minimum magnetic field is sensed near the rotors.

GPS. See global positioning system.

GPS Approach Overlay Program. An authorization for 

pilots to use GPS avionics under IFR for flying designated 

existing nonprecision instrument approach procedures, with 

the exception of LOC, LDA, and SDF procedures.

GPWS. See ground proximity warning system.

Graveyard spiral. The illusion of the cessation of a turn 

while still in a prolonged, coordinated, constant rate turn, 

which can lead a disoriented pilot to a loss of control of the 

aircraft.

Great circle route. The shortest distance across the surface 

of a sphere (the Earth) between two points on the surface.

Ground adjustable trim tab. Non-movable metal trim tab 

on a control surface. Bent in one direction or another while 

on the ground to apply trim forces to the control surface.

Ground effect. The condition of slightly increased air 

pressure below an airplane wing or helicopter rotor system 

that increases the amount of lift produced. It exists within 

approximately one wing span or one rotor diameter from the 

ground. It results from a reduction in upwash, downwash, 

and wingtip vortices, and provides a corresponding decrease 

in induced drag.

Ground proximity warning system (GPWS). A system 

designed to determine an aircraft’s clearance above the Earth 

and provides limited predictability about aircraft position 

relative to rising terrain.

Groundspeed. Speed over the ground, either closing speed to 

the station or waypoint, or speed over the ground in whatever 

direction the aircraft is going at the moment, depending upon 

the navigation system used.

GS. See glideslope.

GWPS. See ground proximity warning system.

Gyroscopic precession. An inherent quality of rotating 

bodies, which causes an applied force to be manifested 90° 

in the direction of rotation from the point where the force 

is applied.

HAA. See height above airport.

HAL. See height above landing.
G-14

HAT. See height above touchdown elevation.

Hazardous attitudes. Five aeronautical decision-making 

attitudes that may contribute to poor pilot judgment: antiauthority, impulsivity, invulnerability, machismo, and 

resignation.

Hazardous Inflight Weather Advisory Service (HIWAS). 

Service providing recorded weather forecasts broadcast to 

airborne pilots over selected VORs.

Head-up display (HUD). A special type of flight viewing 

screen that allows the pilot to watch the flight instruments 

and other data while looking through the windshield of the 

aircraft for other traffic, the approach lights, or the runway.

Heading. The direction in which the nose of the aircraft is 

pointing during flight.

Heading indicator. An instrument which senses airplane 

movement and displays heading based on a 360° azimuth, 

with the final zero omitted. The heading indicator, also called 

a directional gyro (DG), is fundamentally a mechanical 

instrument designed to facilitate the use of the magnetic 

compass. The heading indicator is not affected by the forces 

that make the magnetic compass difficult to interpret.

Headwork. Required to accomplish a conscious, rational 

thought process when making decisions. Good decisionmaking involves risk identification and assessment, 

information processing, and problem solving.

Height above airport (HAA). The height of the MDA above 

the published airport elevation.

Height above landing (HAL). The height above a designated 

helicopter landing area used for helicopter instrument 

approach procedures.

Height above touchdown elevation (HAT). The DA/DH or 

MDA above the highest runway elevation in the touchdown 

zone (first 3,000 feet of the runway).

HF. High frequency.

Hg. Abbreviation for mercury, from the Latin 

hydrargyrum.

High performance aircraft. An aircraft with an engine of 

more than 200 horsepower.

Histotoxic hypoxia. The inability of cells to effectively use 

oxygen. Plenty of oxygen is being transported to the cells 

that need it, but they are unable to use it.

HIWAS. See Hazardous Inflight Weather Advisory 

Service.

Holding. A predetermined maneuver that keeps aircraft 

within a specified airspace while awaiting further clearance 

from ATC.

Holding pattern. A racetrack pattern, involving two turns 

and two legs, used to keep an aircraft within a prescribed 

airspace with respect to a geographic fix. A standard pattern 

uses right turns; nonstandard patterns use left turns.

Homing. Flying the aircraft on any heading required to keep 

the needle pointing to the 0° relative bearing position.

Horizontal situation indicator (HSI). A flight navigation 

instrument that combines the heading indicator with a CDI, 

in order to provide the pilot with better situational awareness 

of location with respect to the courseline.

Horsepower. The term, originated by inventor James Watt, 

means the amount of work a horse could do in one second. 

One horsepower equals 550 foot-pounds per second, or 

33,000 foot-pounds per minute.

Hot start. In gas turbine engines, a start which occurs with 

normal engine rotation, but exhaust temperature exceeds 

prescribed limits. This is usually caused by an excessively 

rich mixture in the combustor. The fuel to the engine must 

be terminated immediately to prevent engine damage.

HSI. See horizontal situation indicator.

HUD. See head-up display.

Human factors. A multidisciplinary field encompassing the 

behavioral and social sciences, engineering, and physiology, 

to consider the variables that influence individual and 

crew performance for the purpose of optimizing human 

performance and reducing errors.

Hung start. In gas turbine engines, a condition of normal 

light off but with rpm remaining at some low value rather than 

increasing to the normal idle rpm. This is often the result of 

insufficient power to the engine from the starter. In the event 

of a hung start, the engine should be shut down.
G-15

Hydroplaning. A condition that exists when landing on a 

surface with standing water deeper than the tread depth of 

the tires. When the brakes are applied, there is a possibility 

that the brake will lock up and the tire will ride on the 

surface of the water, much like a water ski. When the tires 

are hydroplaning, directional control and braking action 

are virtually impossible. An effective anti-skid system can 

minimize the effects of hydroplaning.

Hypemic hypoxia. A type of hypoxia that is a result of 

oxygen deficiency in the blood, rather than a lack of inhaled 

oxygen. It can be caused by a variety of factors. Hypemic 

means “not enough blood.”

Hyperventilation. Occurs when an individual is experiencing 

emotional stress, fright, or pain, and the breathing rate and 

depth increase, although the carbon dioxide level in the 

blood is already at a reduced level. The result is an excessive 

loss of carbon dioxide from the body, which can lead to 

unconsciousness due to the respiratory system’s overriding 

mechanism to regain control of breathing.

Hypoxia. A state of oxygen deficiency in the body sufficient 

to impair functions of the brain and other organs.

Hypoxic hypoxia. This type of hypoxia is a result of 

insufficient oxygen available to the lungs. A decrease of 

oxygen molecules at sufficient pressure can lead to hypoxic 

hypoxia.

IAF. See initial approach fix.

IAP. See instrument approach procedures.

IAS. See indicated airspeed.

ICAO. See International Civil Aviation Organization.

Ident. Air Traffic Control request for a pilot to push 

the button on the transponder to identify return on the 

controller’s scope.

IFR. See instrument flight rules.

ILS. See instrument landing system.

ILS categories. Categories of instrument approach 

procedures allowed at airports equipped with the following 

types of instrument landing systems:

ILS Category I: Provides for approach to a height 

above touchdown of not less than 200 feet, and with 

runway visual range of not less than 1,800 feet.

ILS Category II: Provides for approach to a height 

above touchdown of not less than 100 feet and with 

runway visual range of not less than 1,200 feet.

ILS Category IIIA: Provides for approach without 

a decision height minimum and with runway visual 

range of not less than 700 feet.

ILS Category IIIB: Provides for approach without 

a decision height minimum and with runway visual 

range of not less than 150 feet.

ILS Category IIIC: Provides for approach without a 

decision height minimum and without runway visual 

range minimum.

IMC. See instrument meteorological conditions.

Inclinometer. An instrument consisting of a curved glass 

tube, housing a glass ball, and damped with a fluid similar 

to kerosene. It may be used to indicate inclination, as a level, 

or, as used in the turn indicators, to show the relationship 

between gravity and centrifugal force in a turn.

Indicated airspeed (IAS). Shown on the dial of the 

instrument airspeed indicator on an aircraft. Indicated 

airspeed (IAS) is the airspeed indicator reading uncorrected 

for instrument, position, and other errors. Indicated airspeed 

means the speed of an aircraft as shown on its pitot static 

airspeed indicator calibrated to reflect standard atmosphere 

adiabatic compressible flow at sea level uncorrected for 

airspeed system errors. Calibrated airspeed (CAS) is IAS 

corrected for instrument errors, position error (due to 

incorrect pressure at the static port) and installation errors.

Indicated altitude. The altitude read directly from the 

altimeter (uncorrected) when it is set to the current altimeter 

setting.

Indirect indication. A reflection of aircraft pitch-and-bank 

attitude by instruments other than the attitude indicator.

Induced drag. Drag caused by the same factors that produce 

lift; its amount varies inversely with airspeed. As airspeed 

decreases, the angle of attack must increase, in turn increasing 

induced drag.

Induction icing. A type of ice in the induction system that 

reduces the amount of air available for combustion. The most 

commonly found induction icing is carburetor icing.

Inertial navigation system (INS). A computer-based 

navigation system that tracks the movement of an aircraft 

via signals produced by onboard accelerometers. The initial 
G-16

location of the aircraft is entered into the computer, and all 

subsequent movement of the aircraft is sensed and used to 

keep the position updated. An INS does not require any inputs 

from outside signals.

Initial approach fix (IAF). The fix depicted on IAP charts 

where the instrument approach procedure (IAP) begins unless 

otherwise authorized by ATC.

Inoperative components. Higher minimums are prescribed 

when the specified visual aids are not functioning; this 

information is listed in the Inoperative Components Table found 

in the United States Terminal Procedures Publications.

INS. See inertial navigation system.

Instantaneous vertical speed indicator (IVSI). Assists in 

interpretation by instantaneously indicating the rate of climb 

or descent at a given moment with little or no lag as displayed 

in a vertical speed indicator (VSI).

Instrument approach procedures (IAP). A series of 

predetermined maneuvers for the orderly transfer of an 

aircraft under IFR from the beginning of the initial approach 

to a landing or to a point from which a landing may be 

made visually.

Instrument flight rules (IFR). Rules and regulations 

established by the Federal Aviation Administration to govern 

flight under conditions in which flight by outside visual 

reference is not safe. IFR flight depends upon flying by 

reference to instruments in the flight deck, and navigation is 

accomplished by reference to electronic signals.

Instrument landing system (ILS). An electronic system 

that provides both horizontal and vertical guidance to a 

specific runway, used to execute a precision instrument 

approach procedure.

Instrument meteorological conditions (IMC).

Meteorological conditions expressed in terms of visibility, 

distance from clouds, and ceiling less than the minimums 

specified for visual meteorological conditions, requiring 

operations to be conducted under IFR.

Instrument takeoff. Using the instruments rather than 

outside visual cues to maintain runway heading and execute 

a safe takeoff.

Intercooler. A device used to reduce the temperatures of the 

compressed air before it enters the fuel metering device. The 

resulting cooler air has a higher density, which permits the 

engine to be operated with a higher power setting.

Interference drag. Drag generated by the collision of 

airstreams creating eddy currents, turbulence, or restrictions 

to smooth flow.

International Civil Aviation Organization (ICAO). The 

United Nations agency for developing the principles and 

techniques of international air navigation, and fostering planning 

and development of international civil air transport.

International standard atmosphere (IAS). A model of 

standard variation of pressure and temperature. 

Interpolation. The estimation of an intermediate value 

of a quantity that falls between marked values in a series. 

Example: In a measurement of length, with a rule that is 

marked in eighths of an inch, the value falls between 3/8 

inch and 1/2 inch. The estimated (interpolated) value might 

then be said to be 7/16 inch.

Inversion. An increase in temperature with altitude.

Inversion illusion. The feeling that the aircraft is tumbling 

backwards, caused by an abrupt change from climb to straightand-level flight while in situations lacking visual reference.

Inverter. A solid-state electronic device that converts D.C. 

into A.C. current of the proper voltage and frequency to 

operate A.C. gyro instruments.

Isobars. Lines which connect points of equal barometric 

pressure.

Isogonic lines. Lines drawn across aeronautical charts to 

connect points having the same magnetic variation.

IVSI. See instantaneous vertical speed indicator.

Jet route. A route designated to serve flight operations from 

18,000 feet MSL up to and including FL 450.

Jet stream. A high-velocity narrow stream of winds, usually 

found near the upper limit of the troposphere, which flows 

generally from west to east.

Judgment. The mental process of recognizing and analyzing 

all pertinent information in a particular situation, a rational 

evaluation of alternative actions in response to it, and a timely 

decision on which action to take.

KIAS. Knots indicated airspeed.
G-17

Kollsman window. A barometric scale window of a 

sensitive altimeter used to adjust the altitude for the 

altimeter setting.

LAAS. See local area augmentation system.

Lag. The delay that occurs before an instrument needle attains 

a stable indication.

Land breeze. A coastal breeze flowing from land to sea 

caused by temperature differences when the sea surface is 

warmer than the adjacent land. The land breeze usually occurs 

at night and alternates with the sea breeze that blows in the 

opposite direction by day.

Land as soon as possible. Land without delay at the nearest 

suitable area, such as an open field, at which a safe approach 

and landing is assured.

Land as soon as practical. The landing site and duration of 

flight are at the discretion of the pilot. Extended flight beyond 

the nearest approved landing area is not recommended.

Land immediately. The urgency of the landing is paramount. 

The primary consideration is to ensure the survival of the 

occupants. Landing in trees, water, or other unsafe areas 

should be considered only as a last resort.

Lateral axis. An imaginary line passing through the center 

of gravity of an airplane and extending across the airplane 

from wingtip to wingtip.

Lateral stability (rolling). The stability about the 

longitudinal axis of an aircraft. Rolling stability or the ability 

of an airplane to return to level flight due to a disturbance 

that causes one of the wings to drop.

Latitude. Measurement north or south of the equator in 

degrees, minutes, and seconds. Lines of latitude are also 

referred to as parallels.

LDA. See localizer-type directional aid.

Lead radial. The radial at which the turn from the DME arc 

to the inbound course is started.

Leading edge. The part of an airfoil that meets the airflow 

first.

Leading edge devices. High lift devices which are found 

on the leading edge of the airfoil. The most common types 

are fixed slots, movable slats, and leading edge flaps.

Leading-edge flap. A portion of the leading edge of an 

airplane wing that folds downward to increase the camber, 

lift, and drag of the wing. The leading-edge flaps are 

extended for takeoffs and landings to increase the amount of 

aerodynamic lift that is produced at any given airspeed.

Leans, the. A physical sensation caused by an abrupt 

correction of a banked attitude entered too slowly to 

stimulate the motion sensing system in the inner ear. The 

abrupt correction can create the illusion of banking in the 

opposite direction.

Licensed empty weight. The empty weight that consists 

of the airframe, engine(s), unusable fuel, and undrainable 

oil plus standard and optional equipment as specified in the 

equipment list. Some manufacturers used this term prior to 

GAMA standardization.

Lift. A component of the total aerodynamic force on an airfoil 

and acts perpendicular to the relative wind.

Limit load factor. Amount of stress, or load factor, that an 

aircraft can withstand before structural damage or failure 

occurs.

Lines of flux. Invisible lines of magnetic force passing 

between the poles of a magnet.

L/MF. See low or medium frequency.

LMM. See locator middle marker.

Load factor. The ratio of a specified load to the total weight 

of the aircraft. The specified load is expressed in terms of 

any of the following: aerodynamic forces, inertial forces, or 

ground or water reactions.

Loadmeter. A type of ammeter installed between the generator 

output and the main bus in an aircraft electrical system.

LOC. See localizer.

Local area augmentation system (LAAS). A differential 

global positioning system (DGPS) that improves the accuracy 

of the system by determining position error from the GPS 

satellites, then transmitting the error, or corrective factors, 

to the airborne GPS receiver.

Localizer (LOC). The portion of an ILS that gives left/right 

guidance information down the centerline of the instrument 

runway for final approach.
G-18

Localizer-type directional aid (LDA). A NAVAID used 

for nonprecision instrument approaches with utility and 

accuracy comparable to a localizer but which is not a part 

of a complete ILS and is not aligned with the runway. Some 

LDAs are equipped with a glideslope.

Locator middle marker (LMM). Nondirectional radio 

beacon (NDB) compass locator, collocated with a middle 

marker (MM).

Locator outer marker (LOM). NDB compass locator, 

collocated with an outer marker (OM).

LOM. See locator outer marker.

Longitude. Measurement east or west of the Prime Meridian 

in degrees, minutes, and seconds. The Prime Meridian is 0° 

longitude and runs through Greenwich, England. Lines of 

longitude are also referred to as meridians.

Longitudinal axis. An imaginary line through an aircraft 

from nose to tail, passing through its center of gravity. The 

longitudinal axis is also called the roll axis of the aircraft. 

Movement of the ailerons rotates an airplane about its 

longitudinal axis.

Longitudinal stability (pitching). Stability about the lateral 

axis. A desirable characteristic of an airplane whereby it tends 

to return to its trimmed angle of attack after displacement.

Long range navigation (LORAN). An electronic 

navigational system by which hyperbolic lines of position 

are determined by measuring the difference in the time of 

reception of synchronized pulse signals from two fixed 

transmitters. LORAN-A operates in the 1750–1950 kHz 

frequency band. LORAN-C and -D operate in the 100–110 

kHz frequency band.

LORAN. See long range navigation.

LORAN-C. A radio navigation system that utilizes master 

and slave stations transmitting timed pulses. The time 

difference in reception of pulses from several stations 

establishes a hyperbolic line of position, which can be 

identified on a LORAN chart. A fix in position is obtained 

by utilizing signals from two or more stations.

Low or medium frequency. A frequency range between 

190 and 535 kHz with the medium frequency above 300 

kHz. Generally associated with nondirectional beacons 

transmitting a continuous carrier with either a 400 or 1,020 

Hz modulation.

Lubber line. The reference line used in a magnetic compass 

or heading indicator.

MAA. See maximum authorized altitude.

MAC. See mean aerodynamic chord.

Mach number. The ratio of the true airspeed of the aircraft 

to the speed of sound in the same atmospheric conditions, 

named in honor of Ernst Mach, late 19th century physicist. 

Mach meter. The instrument that displays the ratio of the 

speed of sound to the true airspeed an aircraft is flying.

Magnetic bearing (MB). The direction to or from a radio 

transmitting station measured relative to magnetic north.

Magnetic compass. A device for determining direction 

measured from magnetic north.

Magnetic dip. A vertical attraction between a compass 

needle and the magnetic poles. The closer the aircraft is to a 

pole, the more severe the effect.

Magnetic heading (MH). The direction an aircraft is pointed 

with respect to magnetic north.

Magneto. A self-contained, engine-driven unit that supplies 

electrical current to the spark plugs; completely independent 

of the airplane’s electrical system. Normally there are two 

magnetos per engine.

Magnus effect. Lifting force produced when a rotating 

cylinder produces a pressure differential. This is the same 

effect that makes a baseball curve or a golf ball slice.

Mandatory altitude. An altitude depicted on an instrument 

approach chart with the altitude value both underscored and 

overscored. Aircraft are required to maintain altitude at the 

depicted value.

Mandatory block altitude. An altitude depicted on an 

instrument approach chart with two underscored and 

overscored altitude values between which aircraft are 

required to maintain altitude.

Maneuverability. Ability of an aircraft to change directions 

along a flightpath and withstand the stresses imposed upon 

it.

Maneuvering speed (VA). The maximum speed at which full, 

abrupt control movement can be used without overstressing 

the airframe.
G-19

Manifold absolute pressure. The absolute pressure of the 

fuel/air mixture within the intake manifold, usually indicated 

in inches of mercury.

MAP. See missed approach point.

Margin identification. The top and bottom areas on an 

instrument approach chart that depict information about 

the procedure, including airport location and procedure 

identification.

Marker beacon. A low-powered transmitter that directs its 

signal upward in a small, fan-shaped pattern. Used along the 

flight path when approaching an airport for landing, marker 

beacons indicate both aurally and visually when the aircraft 

is directly over the facility.

Mass. The amount of matter in a body.

Maximum altitude. An altitude depicted on an instrument 

approach chart with overscored altitude value at which or 

below aircraft are required to maintain altitude.

Maximum authorized altitude (MAA). A published altitude 

representing the maximum usable altitude or flight level for 

an airspace structure or route segment.

Maximum landing weight. The greatest weight that an 

airplane normally is allowed to have at landing.

Maximum ramp weight. The total weight of a loaded 

aircraft, including all fuel. It is greater than the takeoff 

weight due to the fuel that will be burned during the taxi 

and runup operations. Ramp weight may also be referred to 

as taxi weight.

Maximum takeoff weight. The maximum allowable weight 

for takeoff.

Maximum weight. The maximum authorized weight of 

the aircraft and all of its equipment as specified in the Type 

Certificate Data Sheets (TCDS) for the aircraft.

Maximum zero fuel weight (GAMA). The maximum 

weight, exclusive of usable fuel.

MB. See magnetic bearing.

MCA. See minimum crossing altitude.

MDA. See minimum descent altitude.

MEA. See minimum en route altitude.

Mean aerodynamic chord (MAC). The average distance 

from the leading edge to the trailing edge of the wing.

Mean sea level. The average height of the surface of the 

sea at a particular location for all stages of the tide over a 

19-year period. 

MEL. See minimum equipment list.

Meridians. Lines of longitude.

Mesophere. A layer of the atmosphere directly above the 

stratosphere.

METAR. See Aviation Routine Weather Report.

MFD. See multi-function display.

MH. See magnetic heading.

MHz. Megahertz.

Microburts. A strong downdraft which normally occurs over 

horizontal distances of 1 NM or less and vertical distances of 

less than 1,000 feet. In spite of its small horizontal scale, an 

intense microburst could induce windspeeds greater than 100 

knots and downdrafts as strong as 6,000 feet per minute.

Microwave landing system (MLS). A precision instrument 

approach system operating in the microwave spectrum which 

normally consists of an azimuth station, elevation station, 

and precision distance measuring equipment.

Mileage breakdown. A fix indicating a course change 

that appears on the chart as an “x” at a break between two 

segments of a federal airway.

Military operations area (MOA). Airspace established for 

the purpose of separating certain military training activities 

from IFR traffic.

Military training route (MTR). Airspace of defined vertical 

and lateral dimensions established for the conduct of military 

training at airspeeds in excess of 250 knots indicated airspeed 

(KIAS).

Minimum altitude. An altitude depicted on an instrument 

approach chart with the altitude value underscored. Aircraft are 

required to maintain altitude at or above the depicted value.

Minimum crossing altitude (MCA). The lowest allowed 

altitude at certain fixes an aircraft must cross when proceeding 

in the direction of a higher minimum en route altitude 

(MEA).
G-20

Minimum descent altitude (MDA). The lowest altitude (in 

feet MSL) to which descent is authorized on final approach, 

or during circle-to-land maneuvering in execution of a 

nonprecision approach.

Minimum drag. The point on the total drag curve where 

the lift-to-drag ratio is the greatest. At this speed, total drag 

is minimized.

Minimum en route altitude (MEA). The lowest published 

altitude between radio fixes that ensures acceptable 

navigational signal coverage and meets obstacle clearance 

requirements between those fixes.

Minimum equipment list (MEL). A list developed for larger 

aircraft that outlines equipment that can be inoperative for 

various types of flight including IFR and icing conditions. This 

list is based on the master minimum equipment list (MMEL) 

developed by the FAA and must be approved by the FAA for 

use. It is specific to an individual aircraft make and model.

Minimum obstruction clearance altitude (MOCA). The 

lowest published altitude in effect between radio fixes on VOR 

airways, off-airway routes, or route segments, which meets 

obstacle clearance requirements for the entire route segment 

and which ensures acceptable navigational signal coverage 

only within 25 statute (22 nautical) miles of a VOR.

Minimum reception altitude (MRA). The lowest altitude 

at which an airway intersection can be determined.

Minimum safe altitude (MSA). The minimum altitude 

depicted on approach charts which provides at least 1,000 feet 

of obstacle clearance for emergency use within a specified 

distance from the listed navigation facility.

Minimum vectoring altitude (MVA). An IFR altitude lower 

than the minimum en route altitude (MEA) that provides 

terrain and obstacle clearance.

Minimums section. The area on an IAP chart that displays the 

lowest altitude and visibility requirements for the approach.

Missed approach. A maneuver conducted by a pilot when an 

instrument approach cannot be completed to a landing.

Missed approach point (MAP). A point prescribed in each 

instrument approach at which a missed approach procedure 

shall be executed if the required visual reference has not 

been established.

Mixed ice. A mixture of clear ice and rime ice.

MLS. See microwave landing system.

MM. Middle marker.

MOA. See military operations area.

MOCA. See minimum obstruction clearance altitude.

Mode C. Altitude reporting transponder mode.

Moment. The product of the weight of an item multiplied 

by its arm. Moments are expressed in pound-inches (lb-in). 

Total moment is the weight of the airplane multiplied by the 

distance between the datum and the CG.

Moment arm. The distance from a datum to the applied 

force.

Moment index (or index). A moment divided by a constant 

such as 100, 1,000, or 10,000. The purpose of using a moment 

index is to simplify weight and balance computations of 

airplanes where heavy items and long arms result in large, 

unmanageable numbers.

Monocoque. A shell-like fuselage design in which the 

stressed outer skin is used to support the majority of imposed 

stresses. Monocoque fuselage design may include bulkheads 

but not stringers.

Monoplanes. Airplanes with a single set of wings.

Movable slat. A movable auxiliary airfoil on the leading edge 

of a wing. It is closed in normal flight but extends at high 

angles of attack. This allows air to continue flowing over the 

top of the wing and delays airflow separation.

MRA. See minimum reception altitude.

MSA. See minimum safe altitude.

MSL. See mean sea level.

MTR. See military training route.

Multi-function display (MFD). Small screen (CRT or LCD) 

in an aircraft that can be used to display information to the 

pilot in numerous configurable ways. Often an MFD will be 

used in concert with a primary flight display.

MVA. See minimum vectoring altitude.

N1. Rotational speed of the low pressure compressor in a 

turbine engine.
G-21

N2. Rotational speed of the high pressure compressor in a 

turbine engine.

Nacelle. A streamlined enclosure on an aircraft in which 

an engine is mounted. On multiengine propeller-driven 

airplanes, the nacelle is normally mounted on the leading 

edge of the wing.

NACG. See National Aeronautical Charting Group.

NAS. See National Airspace System.

National Airspace System (NAS). The common network of 

United States airspace—air navigation facilities, equipment 

and services, airports or landing areas; aeronautical charts, 

information and services; rules, regulations and procedures, 

technical information; and manpower and material.

National Aeronautical Charting Group (NACG). A 

Federal agency operating under the FAA, responsible for 

publishing charts such as the terminal procedures and en 

route charts.

National Route Program (NRP). A set of rules and 

procedures designed to increase the flexibility of user flight 

planning within published guidelines.

National Security Area (NSA). Areas consisting of airspace of 

defined vertical and lateral dimensions established at locations 

where there is a requirement for increased security and safety 

of ground facilities. Pilots are requested to voluntarily avoid 

flying through the depicted NSA. When it is necessary to 

provide a greater level of security and safety, flight in NSAs 

may be temporarily prohibited. Regulatory prohibitions are 

disseminated via NOTAMs.

National Transportation Safety Board (NTSB). A United 

States Government independent organization responsible for 

investigations of accidents involving aviation, highways, 

waterways, pipelines, and railroads in the United States. 

NTSB is charged by congress to investigate every civil 

aviation accident in the United States.

NAVAID. Naviagtional aid.

NAV/COM. Navigation and communication radio.

NDB. See nondirectional radio beacon.

Negative static stability. The initial tendency of an aircraft 

to continue away from the original state of equilibrium after 

being disturbed.

Neutral static stability. The initial tendency of an aircraft 

to remain in a new condition after its equilibrium has been 

disturbed.

NM. Nautical mile.

NOAA. National Oceanic and Atmospheric Administration.

No-gyro approach. A radar approach that may be used in 

case of a malfunctioning gyro-compass or directional gyro. 

Instead of providing the pilot with headings to be flown, 

the controller observes the radar track and issues control 

instructions “turn right/left” or “stop turn,” as appropriate.

Nondirectional radio beacon (NDB). A ground-based radio 

transmitter that transmits radio energy in all directions.

Nonprecision approach. A standard instrument approach 

procedure in which only horizontal guidance is provided.

No procedure turn (NoPT). Term used with the appropriate 

course and altitude to denote that the procedure turn is not 

required.

NoPT. See no procedure turn.

NOTAM. See Notice to Airmen.

Notice to Airmen (NOTAM). A notice filed with an aviation 

authority to alert aircraft pilots of any hazards en route or at 

a specific location. The authority in turn provides means of 

disseminating relevant NOTAMs to pilots.

NRP. See National Route Program.

NSA. See National Security Area.

NTSB. See National Transportation Safety Board.

NWS. National Weather Service.

Obstacle departure procedures (ODP). A preplanned 

instrument flight rule (IFR) departure procedure printed for 

pilot use in textual or graphic form to provide obstruction 

clearance via the least onerous route from the terminal area to 

the appropriate en route structure. ODPs are recommended

for obstruction clearance and may be flown without ATC 

clearance unless an alternate departure procedure (SID or 

radar vector) has been specifically assigned by ATC.

Obstruction lights. Lights that can be found both on and off 

an airport to identify obstructions.
G-22

Occluded front. A frontal occlusion occurs when a fastmoving cold front catches up with a slow moving warm front. 

The difference in temperature within each frontal system is 

a major factor in determining whether a cold or warm front 

occlusion occurs.

ODP. See obstacle departure procedures. 

OM. Outer marker.

Omission error. The failure to anticipate significant 

instrument indications following attitude changes; for 

example, concentrating on pitch control while forgetting 

about heading or roll information, resulting in erratic control 

of heading and bank.

Optical illusion. A misleading visual image. For the 

purpose of this handbook, the term refers to the brain’s 

misinterpretation of features on the ground associated 

with landing, which causes a pilot to misread the spatial 

relationships between the aircraft and the runway.

Orientation. Awareness of the position of the aircraft and 

of oneself in relation to a specific reference point.

Otolith organ. An inner ear organ that detects linear 

acceleration and gravity orientation.

Outer marker. A marker beacon at or near the glideslope 

intercept altitude of an ILS approach. It is normally located 

four to seven miles from the runway threshold on the 

extended centerline of the runway.

Outside air temperature (OAT). The measured or indicated 

air temperature (IAT) corrected for compression and friction 

heating. Also referred to as true air temperature.

Overcontrolling. Using more movement in the control 

column than is necessary to achieve the desired pitch-andbank condition.

Overboost. A condition in which a reciprocating engine has 

exceeded the maximum manifold pressure allowed by the 

manufacturer. Can cause damage to engine components.

Overpower. To use more power than required for the purpose 

of achieving a faster rate of airspeed change.

P-static. See precipitation static.

PAPI. See precision approach path indicator.

PAR. See precision approach radar.

Parallels. Lines of latitude.

Parasite drag. Drag caused by the friction of air moving 

over the aircraft structure; its amount varies directly with 

the airspeed.

Payload (GAMA). The weight of occupants, cargo, and 

baggage.

Personality. The embodiment of personal traits and 

characteristics of an individual that are set at a very early 

age and extremely resistant to change.

P-factor. A tendency for an aircraft to yaw to the left due to 

the descending propeller blade on the right producing more 

thrust than the ascending blade on the left. This occurs when 

the aircraft’s longitudinal axis is in a climbing attitude in 

relation to the relative wind. The P-factor would be to the right 

if the aircraft had a counterclockwise rotating propeller.

PFD. See primary flight display.

Phugoid oscillations. Long-period oscillations of an 

aircraft around its lateral axis. It is a slow change in pitch 

accompanied by equally slow changes in airspeed. Angle 

of attack remains constant, and the pilot often corrects for 

phugoid oscillations without even being aware of them.

PIC. See pilot in command.

Pilotage. Navigation by visual reference to landmarks.

Pilot in command (PIC). The pilot responsible for the 

operation and safety of an aircraft.

Pilot report (PIREP). Report of meteorological phenomena 

encountered by aircraft.

Pilot’s Operating Handbook/Airplane Flight Manual 

(POH/AFM). FAA-approved documents published by the 

airframe manufacturer that list the operating conditions for 

a particular model of aircraft.

PIREP. See pilot report.

Pitot pressure. Ram air pressure used to measure airspeed.

Pitot-static head. A combination pickup used to sample pitot 

pressure and static air pressure.

Plan view. The overhead view of an approach procedure on 

an instrument approach chart. The plan view depicts the routes 

that guide the pilot from the en route segments to the IAF.
G-23

Planform. The shape or form of a wing as viewed from 

above. It may be long and tapered, short and rectangular, or 

various other shapes.

Pneumatic. Operation by the use of compressed air.

POH/AFM. See Pilot’s Operating Handbook/Airplane 

Flight Manual.

Point-in-space approach. A type of helicopter instrument 

approach procedure to a missed approach point more than 

2,600 feet from an associated helicopter landing area.

Poor judgment chain. A series of mistakes that may lead 

to an accident or incident. Two basic principles generally 

associated with the creation of a poor judgment chain are: 

(1) one bad decision often leads to another; and (2) as a 

string of bad decisions grows, it reduces the number of 

subsequent alternatives for continued safe flight. ADM is 

intended to break the poor judgment chain before it can 

cause an accident or incident.

Position error. Error in the indication of the altimeter, ASI, 

and VSI caused by the air at the static system entrance not 

being absolutely still.

Position report. A report over a known location as 

transmitted by an aircraft to ATC.

Positive static stability. The initial tendency to return to a 

state of equilibrium when disturbed from that state.

Power. Implies work rate or units of work per unit of time, 

and as such, it is a function of the speed at which the force is 

developed. The term “power required” is generally associated 

with reciprocating engines.

Powerplant. A complete engine and propeller combination 

with accessories.

Precession. The characteristic of a gyroscope that causes an 

applied force to be felt, not at the point of application, but 

90° from that point in the direction of rotation.

Precipitation. Any or all forms of water particles (rain, 

sleet, hail, or snow) that fall from the atmosphere and reach 

the surface.

Precipitation static (P-static). A form of radio interference 

caused by rain, snow, or dust particles hitting the antenna and 

inducing a small radio-frequency voltage into it.

Precision approach. A standard instrument approach 

procedure in which both vertical and horizontal guidance 

is provided.

Precision approach path indicator (PAPI). A system of 

lights similar to the VASI, but consisting of one row of lights 

in two- or four-light systems. A pilot on the correct glideslope 

will see two white lights and two red lights. See VASI.

Precision approach radar (PAR). A type of radar used 

at an airport to guide an aircraft through the final stages of 

landing, providing horizontal and vertical guidance. The 

radar operator directs the pilot to change heading or adjust 

the descent rate to keep the aircraft on a path that allows it 

to touch down at the correct spot on the runway.

Precision runway monitor (PRM). System allows 

simultaneous, independent instrument flight rules (IFR) 

approaches at airports with closely spaced parallel runways.

Preferred IFR routes. Routes established in the major 

terminal and en route environments to increase system 

efficiency and capacity. IFR clearances are issued based on 

these routes, listed in the A/FD except when severe weather 

avoidance procedures or other factors dictate otherwise.

Preignition. Ignition occurring in the cylinder before the 

time of normal ignition. Preignition is often caused by a 

local hot spot in the combustion chamber igniting the fuelair mixture.

Pressure altitude. Altitude above the standard 29.92 "Hg 

plane.

Pressure demand oxygen system. A demand oxygen system 

that supplies 100 percent oxygen at sufficient pressure above 

the altitude where normal breathing is adequate. Also referred 

to as a pressure breathing system.

Prevailing visibility. The greatest horizontal visibility 

equaled or exceeded throughout at least half the horizon 

circle (which is not necessarily continuous).

Preventive maintenance. Simple or minor preservative 

operations and the replacement of small standard parts 

not involving complex assembly operation as listed in 14 

CFR part 43, appendix A. Certificated pilots may perform 

preventive maintenance on any aircraft that is owned or 

operated by them provided that the aircraft is not used in air 

carrier service.
G-24

Primary and supporting. A method of attitude instrument 

flying using the instrument that provides the most direct 

indication of attitude and performance.

Primary flight display (PFD). A display that provides 

increased situational awareness to the pilot by replacing the 

traditional six instruments used for instrument flight with 

an easy-to-scan display that provides the horizon, airspeed, 

altitude, vertical speed, trend, trim, and rate of turn among 

other key relevant indications.

PRM. See precision runway monitor.

Procedure turn. A maneuver prescribed when it is necessary 

to reverse direction to establish an aircraft on the intermediate 

approach segment or final approach course.

Profile view. Side view of an IAP chart illustrating the vertical 

approach path altitudes, headings, distances, and fixes.

Prohibited area. Designated airspace within which flight of 

aircraft is prohibited.

Propeller. A device for propelling an aircraft that, 

when rotated, produces by its action on the air, a thrust 

approximately perpendicular to its plane of rotation. It 

includes the control components normally supplied by its 

manufacturer.

Propeller/rotor modulation error. Certain propeller rpm 

settings or helicopter rotor speeds can cause the VOR 

course deviation indicator (CDI) to fluctuate as much as 

±6°. Slight changes to the rpm setting will normally smooth 

out this roughness.

Rabbit, the. High-intensity flasher system installed at many 

large airports. The flashers consist of a series of brilliant 

blue-white bursts of light flashing in sequence along the 

approach lights, giving the effect of a ball of light traveling 

toward the runway.

Radar. A system that uses electromagnetic waves to identify 

the range, altitude, direction, or speed of both moving and 

fixed objects such as aircraft, weather formations, and terrain. 

The term RADAR was coined in 1941 as an acronym for 

Radio Detection and Ranging. The term has since entered 

the English language as a standard word, radar, losing the 

capitalization in the process. 

Radar approach. The controller provides vectors while 

monitoring the progress of the flight with radar, guiding 

the pilot through the descent to the airport/heliport or to a 

specific runway.

Radar services. Radar is a method whereby radio waves are 

transmitted into the air and are then received when they have 

been reflected by an object in the path of the beam. Range 

is determined by measuring the time it takes (at the speed 

of light) for the radio wave to go out to the object and then 

return to the receiving antenna. The direction of a detected 

object from a radar site is determined by the position of the 

rotating antenna when the reflected portion of the radio wave 

is received.

Radar summary chart. A weather product derived from the 

national radar network that graphically displays a summary 

of radar weather reports.

Radar weather report (SD). A report issued by radar 

stations at 35 minutes after the hour, and special reports 

as needed. Provides information on the type, intensity, and 

location of the echo tops of the precipitation.

Radials. The courses oriented from a station.

Radio or radar altimeter. An electronic altimeter that 

determines the height of an aircraft above the terrain by 

measuring the time needed for a pulse of radio-frequency 

energy to travel from the aircraft to the ground and return.

Radio frequency (RF). A term that refers to alternating 

current (AC) having characteristics such that, if the current is 

input to antenna, an electromagnetic (EM) field is generated 

suitable for wireless broadcasting and/or communications.

Radio magnetic indicator (RMI). An electronic navigation 

instrument that combines a magnetic compass with an ADF 

or VOR. The card of the RMI acts as a gyro-stabilized 

magnetic compass, and shows the magnetic heading the 

aircraft is flying.

Radiosonde. A weather instrument that observes and reports 

meteorological conditions from the upper atmosphere. This 

instrument is typically carried into the atmosphere by some 

form of weather balloon.

Radio wave. An electromagnetic (EM ) wave with frequency 

characteristics useful for radio transmission.

RAIM. See receiver autonomous integrity monitoring.

RAM recovery. The increase in thrust as a result of ram air 

pressures and density on the front of the engine caused by 

air velocity.
G-25

Random RNAV routes. Direct routes, based on area 

navigation capability, between waypoints defined in terms 

of latitude/longitude coordinates, degree-distance fixes, or 

offsets from established routes/airways at a specified distance 

and direction.

Ranging signals. Transmitted from the GPS satellite, signals 

allowing the aircraft’s receiver to determine range (distance) 

from each satellite.

Rapid decompression. The almost instantaneous loss of 

cabin pressure in aircraft with a pressurized cockpit or 

cabin.

RB. See relative bearing.

RBI. See relative bearing indicator.

RCO. See remote communications outlet.

Receiver autonomous integrity monitoring (RAIM).

A system used to verify the usability of the received GPS 

signals and warns the pilot of any malfunction in the 

navigation system. This system is required for IFR-certified 

GPS units. 

Recommended altitude. An altitude depicted on an 

instrument approach chart with the altitude value neither 

underscored nor overscored. The depicted value is an 

advisory value.

Receiver-transmitter (RT). A system that receives and 

transmits a signal and an indicator.

Reduced vertical separation minimum (RVSM). Reduces 

the vertical separation between flight levels (FL) 290 and 410 

from 2,000 feet to 1,000 feet, and makes six additional FLs 

available for operation. Also see DRVSM.

Reference circle (also, distance circle). The circle depicted 

in the plan view of an IAP chart that typically has a 10 NM 

radius, within which chart the elements are drawn to scale.

Regions of command. The “regions of normal and reversed 

command” refers to the relationship between speed and the 

power required to maintain or change that speed in flight.

Region of reverse command. Flight regime in which flight 

at a higher airspeed requires a lower power setting and a 

lower airspeed requires a higher power setting in order to 

maintain altitude.

REIL. See runway end identifier lights.

Relative bearing (RB). The angular difference between the 

aircraft heading and the direction to the station, measured 

clockwise from the nose of the aircraft.

Relative bearing indicator (RBI). Also known as the fixedcard ADF, zero is always indicated at the top of the instrument 

and the needle indicates the relative bearing to the station.

Relative humidity. The ratio of the existing amount of 

water vapor in the air at a given temperature to the maximum 

amount that could exist at that temperature; usually expressed 

in percent.

Relative wind. Direction of the airflow produced by an object 

moving through the air. The relative wind for an airplane in 

flight flows in a direction parallel with and opposite to the 

direction of flight; therefore, the actual flight path of the 

airplane determines the direction of the relative wind.

Remote communications outlet (RCO). An unmanned 

communications facility that is remotely controlled by air 

traffic personnel.

Required navigation performance (RNP). A specified level 

of accuracy defined by a lateral area of confined airspace in 

which an RNP-certified aircraft operates.

Restricted area. Airspace designated under 14 CFR part 

73 within which the flight of aircraft, while not wholly 

prohibited, is subject to restriction.

Reverse sensing. The VOR needle appearing to indicate the 

reverse of normal operation.

RF. Radio frequency.

Rhodopsin. The photosensitive pigments that initiate the 

visual response in the rods of the eye.

Rigging. The final adjustment and alignment of an aircraft 

and its flight control system that provides the proper 

aerodynamic characteristics.

Rigidity. The characteristic of a gyroscope that prevents its 

axis of rotation tilting as the Earth rotates.

Rigidity in space. The principle that a wheel with a heavily 

weighted rim spinning rapidly will remain in a fixed position 

in the plane in which it is spinning.
G-26

Rime ice. Rough, milky, opaque ice formed by the 

instantaneous freezing of small supercooled water droplets.

Risk. The future impact of a hazard that is not eliminated 

or controlled.

Risk elements. There are four fundamental risk elements in 

aviation: the pilot, the aircraft, the environment, and the type 

of operation that comprise any given aviation situation.

Risk management. The part of the decision-making process 

which relies on situational awareness, problem recognition, 

and good judgment to reduce risks associated with each 

flight.

RMI. See radio magnetic indicator.

RNAV. See area navigation.

RNP. See required navigation performance.

RT. See receiver-transmitter.

Rudder. The movable primary control surface mounted on the 

trailing edge of the vertical fin of an airplane. Movement of 

the rudder rotates the airplane about its vertical axis.

Ruddervator. A pair of control surfaces on the tail of an 

aircraft arranged in the form of a V. These surfaces, when 

moved together by the control wheel, serve as elevators, and 

when moved differentially by the rudder pedals, serve as a 

rudder.

Runway centerline lights. Runway lighting which consists 

of flush centerline lights spaced at 50-foot intervals beginning 

75 feet from the landing threshold.

Runway edge lights. A component of the runway lighting 

system that is used to outline the edges of runways at night 

or during low visibility conditions. These lights are classified 

according to the intensity they are capable of producing.

Runway end identifier lights (REIL). A pair of synchronized 

flashing lights, located laterally on each side of the runway 

threshold, providing rapid and positive identification of the 

approach end of a runway.

Runway visibility value (RVV). The visibility determined 

for a particular runway by a transmissometer.

Runway visual range (RVR). The instrumentally derived 

horizontal distance a pilot should be able to see down the 

runway from the approach end, based on either the sighting 

of high-intensity runway lights, or the visual contrast of 

other objects.

RVR. See runway visual range.

RVV. See runway visibility value.

SA. See selective availability.

St. Elmo’s Fire. A corona discharge which lights up the aircraft 

surface areas where maximum static discharge occurs.

Satellite ephemeris data. Data broadcast by the GPS 

satellite containing very accurate orbital data for that 

satellite, atmospheric propagation data, and satellite clock 

error data.

Sea breeze. A coastal breeze blowing from sea to land 

caused by the temperature difference when the land surface is 

warmer than the sea surface. The sea breeze usually occurs

during the day and alternates with the land breeze that blows 

in the opposite direction at night.

Sea level engine. A reciprocating aircraft engine having a 

rated takeoff power that is producible only at sea level.

Scan. The first fundamental skill of instrument flight, also 

known as “cross-check;” the continuous and logical observation 

of instruments for attitude and performance information.

Sectional aeronautical charts. Designed for visual 

navigation of slow- or medium-speed aircraft. Topographic 

information on these charts features the portrayal of relief, 

and a judicious selection of visual check points for VFR 

flight. Aeronautical information includes visual and radio 

aids to navigation, airports, controlled airspace, restricted 

areas, obstructions and related data.

SDF. See simplified directional facility.

Selective availability (SA). A satellite technology permitting 

the Department of Defense (DOD) to create, in the interest 

of national security, a significant clock and ephemeris error 

in the satellites, resulting in a navigation error.
G-27

Semicircular canal. An inner ear organ that detects angular 

acceleration of the body.

Semimonocoque. A fuselage design that includes a 

substructure of bulkheads and/or formers, along with 

stringers, to support flight loads and stresses imposed on 

the fuselage.

Sensitive altimeter. A form of multipointer pneumatic 

altimeter with an adjustable barometric scale that allows the 

reference pressure to be set to any desired level.

Service ceiling. The maximum density altitude where the best 

rate-of-climb airspeed will produce a 100-feet-per-minute 

climb at maximum weight while in a clean configuration 

with maximum continuous power.

Servo. A motor or other form of actuator which receives a 

small signal from the control device and exerts a large force 

to accomplish the desired work.

Servo tab. An auxiliary control mounted on a primary control 

surface, which automatically moves in the direction opposite 

the primary control to provide an aerodynamic assist in the 

movement of the control.

SIDS. See standard instrument departure procedures.

SIGMET. The acronym for Significant Meteorological 

information. A weather advisory issued concerning weather 

significant to the safety of all aircraft.

Signal-to-noise ratio. An indication of signal strength 

received compared to background noise, which is a measure 

of the adequacy of the received signal.

Significant weather prognostic. Presents four panels 

showing forecast significant weather.

Simplex. Transmission and reception on the same 

frequency.

Simplified directional facility (SDF). A NAVAID used 

for nonprecision instrument approaches. The final approach 

course is similar to that of an ILS localizer; however, the 

SDF course may be offset from the runway, generally not 

more than 3°, and the course may be wider than the localizer, 

resulting in a lower degree of accuracy.

Single-pilot resource management (SRM). The ability 

for a pilot to manage all resources effectively to ensure the 

outcome of the flight is successful.

Situational awareness. Pilot knowledge of where the aircraft 

is in regard to location, air traffic control, weather, regulations, 

aircraft status, and other factors that may affect flight.

Skidding turn. An uncoordinated turn in which the rate of 

turn is too great for the angle of bank, pulling the aircraft to 

the outside of the turn.

Skills and procedures. The procedural, psychomotor, and 

perceptual skills used to control a specific aircraft or its 

systems. They are the airmanship abilities that are gained 

through conventional training, are perfected, and become 

almost automatic through experience.

Skin friction drag. Drag generated between air molecules 

and the solid surface of the aircraft.

Slant range. The horizontal distance from the aircraft antenna 

to the ground station, due to line-of-sight transmission of the 

DME signal.

Slaved compass. A system whereby the heading gyro is 

“slaved to,” or continuously corrected to bring its direction 

readings into agreement with a remotely located magnetic 

direction sensing device (usually a flux valve or flux gate 

compass).

Slipping turn. An uncoordinated turn in which the aircraft 

is banked too much for the rate of turn, so the horizontal lift 

component is greater than the centrifugal force, pulling the 

aircraft toward the inside of the turn.

Small airplane. An airplane of 12,500 pounds or less 

maximum certificated takeoff weight.

Somatogravic illusion. The misperception of being 

in a nose-up or nose-down attitude, caused by a rapid 

acceleration or deceleration while in flight situations that 

lack visual reference.

Spatial disorientation. The state of confusion due to 

misleading information being sent to the brain from various 

sensory organs, resulting in a lack of awareness of the aircraft 

position in relation to a specific reference point.

Special flight permit. A flight permit issued to an aircraft 

that does not meet airworthiness requirements but is capable 

of safe flight. A special flight permit can be issued to move 

an aircraft for the purposes of maintenance or repair, buyer 

delivery, manufacturer flight tests, evacuation from danger, 

or customer demonstration. Also referred to as a ferry 

permit.
G-28

Special use airspace. Airspace in which flight activities are 

subject to restrictions that can create limitations on the mixed 

use of airspace. Consists of prohibited, restricted, warning, 

military operations, and alert areas.

Special fuel consumption. The amount of fuel in pounds 

per hour consumed or required by an engine per brake 

horsepower or per pound of thrust.

Speed. The distance traveled in a given time.

Spin. An aggravated stall that results in an airplane 

descending in a helical, or corkscrew path.

Spiral instability. A condition that exists when the 

static directional stability of the airplane is very strong as 

compared to the effect of its dihedral in maintaining lateral 

equilibrium.

Spiraling slipstream. The slipstream of a propeller-driven 

airplane rotates around the airplane. This slipstream strikes 

the left side of the vertical fin, causing the aircraft to yaw 

slightly. Rudder offset is sometimes used by aircraft designers 

to counteract this tendency.

Spoilers. High-drag devices that can be raised into the air 

flowing over an airfoil, reducing lift and increasing drag. 

Spoilers are used for roll control on some aircraft. Deploying 

spoilers on both wings at the same time allows the aircraft 

to descend without gainingspeed. Spoilers are also used to 

shorten the ground roll after landing.

SRM. See single-pilot resource management.

SSR. See secondary surveillance radar.

SSV. See standard service volume.

Stabilator. A single-piece horizontal tail surface on an 

airplane that pivots around a central hinge point. A stabilator 

serves the purposes of both the horizontal stabilizer and the 

elevators.

Stability. The inherent quality of an airplane to correct for 

conditions that may disturb its equilibrium, and to return or to 

continue on the original flightpath. It is primarily an airplane 

design characteristic.

Stagnant hypoxia. A type of hypoxia that results when the 

oxygen-rich blood in the lungs is not moving to the tissues 

that need it.

Stall. A rapid decrease in lift caused by the separation of 

airflow from the wing’s surface, brought on by exceeding 

the critical angle of attack. A stall can occur at any pitch 

attitude or airspeed.

Standard atmosphere. At sea level, the standard atmosphere 

consists of a barometric pressure of 29.92 inches of mercury 

("Hg) or 1013.2 millibars, and a temperature of 15 °C (59 

°F). Pressure and temperature normally decrease as altitude 

increases. The standard lapse rate in the lower atmosphere for 

each 1,000 feet of altitude is approximately 1 "Hg and 2 °C 

(3.5 °F). For example, the standard pressure and temperature 

at 3,000 feet mean sea level (MSL) are 26.92 "Hg (29.92 "Hg 

– 3 "Hg) and 9 °C (15 °C – 6 °C).

Standard empty weight (GAMA). This weight consists of 

the airframe, engines, and all items of operating equipment 

that have fixed locations and are permanently installed in the 

airplane including fixed ballast, hydraulic fluid, unusable 

fuel, and full engine oil.

Standard holding pattern. A holding pattern in which all 

turns are made to the right.

Standard instrument departure procedures (SIDS).

Published procedures to expedite clearance delivery and to 

facilitate transition between takeoff and en route operations.

Standard rate turn. A turn in which an aircraft changes its 

direction at a rate of 3° per second (360° in 2 minutes) for 

low- or medium-speed aircraft. For high-speed aircraft, the 

standard rate turn is 11⁄2° per second (360° in 4 minutes).

Standard service volume (SSV). Defines the limits of the 

volume of airspace which the VOR serves.

Standard terminal arrival route (STAR). A preplanned 

IFR ATC arrival procedure published for pilot use in graphic 

and/or textual form.

Standard weights. Weights established for numerous items 

involved in weight and balance computations. These weights 

should not be used if actual weights are available.

STAR. See standard terminal arrival route.

Static longitudinal stability. The aerodynamic pitching 

moments required to return the aircraft to the equilibrium 

angle of attack.
G-29

Static pressure. Pressure of air that is still or not moving, 

measured perpendicular to the surface of the aircraft.

Static stability. The initial tendency an aircraft displays 

when disturbed from a state of equilibrium.

Station. A location in the airplane that is identified by a 

number designating its distance in inches from the datum. 

The datum is, therefore, identified as station zero. An item 

located at station +50 would have an arm of 50 inches.

Stationary front. A front that is moving at a speed of less 

than 5 knots.

Steep turns. In instrument flight, any turn greater than standard 

rate; in visual flight, anything greater than a 45° bank.

Stepdown fix. The point after which additional descent is 

permitted within a segment of an IAP.

Strapdown system. An INS in which the accelerometers 

and gyros are permanently “strapped down” or aligned with 

the three axes of the aircraft.

Stratoshere. A layer of the atmosphere above the tropopause 

extending to a height of approximately 160,000 feet.

Stress. The body’s response to demands placed upon it.

Stress management. The personal analysis of the kinds of 

stress experienced while flying, the application of appropriate 

stress assessment tools, and other coping mechanisms.

Structural icing. The accumulation of ice on the exterior 

of the aircraft.

Sublimation. Process by which a solid is changed to a gas 

without going through the liquid state.

Suction relief valve. A relief valve in an instrument vacuum 

system required to maintain the correct low pressure inside 

the instrument case for the proper operation of the gyros.

Supercharger. An engine- or exhaust-driven air compressor 

used to provide additional pressure to the induction air so the 

engine can produce additional power.

Supercooled water droplets. Water droplets that have 

been cooled below the freezing point, but are still in a liquid 

state.

Surface analysis chart. A report that depicts an analysis of 

the current surface weather. Shows the areas of high and low 

pressure, fronts, temperatures, dewpoints, wind directions 

and speeds, local weather, and visual obstructions.

Synchro. A device used to transmit indications of angular 

movement or position from one location to another.

Synthetic vision. A realistic display depiction of the aircraft 

in relation to terrain and flight path.

TAA. See terminal arrival area.

TACAN. See tactical air navigation.

Tactical air navigation (TACAN). An electronic navigation 

system used by military aircraft, providing both distance and 

direction information.

Takeoff decision speed (V1). Per 14 CFR section 23.51: 

“the calibrated airspeed on the ground at which, as a result 

of engine failure or other reasons, the pilot assumed to have 

made a decision to continue or discontinue the takeoff.”

Takeoff distance. The distance required to complete an 

all-engines operative takeoff to the 35-foot height. It must 

be at least 15 percent less than the distance required for a 

one-engine inoperative engine takeoff. This distance is not 

normally a limiting factor as it is usually less than the oneengine inoperative takeoff distance.

Takeoff safety speed (V2). Per 14 CFR part 1: “A referenced 

airspeed obtained after lift-off at which the required oneengine-inoperative climb performance can be achieved.”

TAWS. See terrain awareness and warning system.

Taxiway lights. Omnidirectional lights that outline the edges 

of the taxiway and are blue in color.

Taxiway turnoff lights. Lights that are flush with the runway 

which emit a steady green color.

TCAS. See traffic alert collision avoidance system. 

TCH. See threshold crossing height.

TDZE. See touchdown zone elevation.

TEC. See Tower En Route Control.
G-30

Technique. The manner in which procedures are executed.

Telephone information briefing service (TIBS).

Telephone recording of area and/or route meteorological 

briefings, airspace procedures, and special aviation-oriented 

announcements.

Temporary flight restriction (TFR). Restriction to flight 

imposed in order to:

1. Protect persons and property in the air or on the 

surface from an existing or imminent flight associated 

hazard;

2. Provide a safe environment for the operation of 

disaster relief aircraft;

3. Prevent an unsafe congestion of sightseeing aircraft 

above an incident;

4. Protect the President, Vice President, or other public 

figures; and,

5. Provide a safe environment for space agency 

operations.

Pilots are expected to check appropriate NOTAMs during 

flight planning when conducting flight in an area where a 

temporary flight restriction is in effect.

Tension. Maintaining an excessively strong grip on the control 

column, usually resulting in an overcontrolled situation.

Terminal aerodrome forecast (TAF). A report established 

for the 5 statute mile radius around an airport. Utilizes the 

same descriptors and abbreviations as the METAR report.

Terminal arrival area (TAA). A procedure to provide a 

new transition method for arriving aircraft equipped with 

FMS and/or GPS navigational equipment. The TAA contains 

a “T” structure that normally provides a NoPT for aircraft 

using the approach.

Terminal instrument approach procedure (TERP). 

Prescribes standardized methods for use in designing 

instrument flight procedures.

TERP. See terminal instrument approach procedure. 

Terminal radar service areas (TRSA). Areas where 

participating pilots can receive additional radar services. The 

purpose of the service is to provide separation between all 

IFR operations and participating VFR aircraft.

Terrain awareness and warning system (TAWS). A 

timed-based system that provides information concerning 

potential hazards with fixed objects by using GPS positioning 

and a database of terrain and obstructions to provide true 

predictability of the upcoming terrain and obstacles.

TFR. See temporary flight restriction.

Thermosphere. The last layer of the atmosphere that 

begins above the mesosphere and gradually fades away into 

space.

Threshold crossing height (TCH). The theoretical height 

above the runway threshold at which the aircraft’s glideslope 

antenna would be if the aircraft maintained the trajectory 

established by the mean ILS glideslope or MLS glidepath.

Thrust. The force which imparts a change in the velocity of a 

mass. This force is measured in pounds but has no element of 

time or rate. The term “thrust required” is generally associated 

with jet engines. A forward force which propels the airplane 

through the air.

Thrust (aerodynamic force). The forward aerodynamic 

force produced by a propeller, fan, or turbojet engine as it 

forces a mass of air to the rear, behind the aircraft.

Thrust line. An imaginary line passing through the center of 

the propeller hub, perpendicular to the plane of the propeller 

rotation.

Time and speed table. A table depicted on an instrument 

approach procedure chart that identifies the distance from the 

FAF to the MAP, and provides the time required to transit 

that distance based on various groundspeeds.

Timed turn. A turn in which the clock and the turn 

coordinator are used to change heading a definite number of 

degrees in a given time.

TIS. See traffic information service.

Title 14 of the Code of Federal Regulations (14 CFR).

Includes the federal aviation regulations governing the 

operation of aircraft, airways, and airmen.

Torque. (1) A resistance to turning or twisting. (2) Forces that 

produce a twisting or rotating motion. (3) In an airplane, the 

tendency of the aircraft to turn (roll) in the opposite direction 

of rotation of the engine and propeller. (4) In helicopters with 

a single, main rotor system, the tendency of the helicopter to 

turn in the opposite direction of the main rotor rotation.
G-31

Torquemeter. An instrument used with some of the larger 

reciprocating engines and turboprop or turboshaft engines to 

measure the reaction between the propeller reduction gears 

and the engine case.

Total drag. The sum of the parasite drag and induced drag.

Touchdown zone elevation (TDZE). The highest elevation 

in the first 3,000 feet of the landing surface, TDZE is 

indicated on the instrument approach procedure chart when 

straight-in landing minimums are authorized.

Touchdown zone lights. Two rows of transverse light bars 

disposed symmetrically about the runway centerline in the 

runway touchdown zone.

Tower En Route Control (TEC). The control of IFR en route 

traffic within delegated airspace between two or more adjacent 

approach control facilities, designed to expedite traffic and 

reduce control and pilot communication requirements.

TPP. See United States Terminal Procedures Publication.

Track. The actual path made over the ground in flight.

Tracking. Flying a heading that will maintain the desired track 

to or from the station regardless of crosswind conditions.

Traffic Alert Collision Avoidance System (TCAS). 

An airborne system developed by the FAA that operates 

independently from the ground-based Air Traffic Control 

system. Designed to increase flight deck awareness of 

proximate aircraft and to serve as a “last line of defense” for 

the prevention of midair collisions.

Traffic information service (TIS). A ground-based service 

providing information to the flight deck via data link using 

the S-mode transponder and altitude encoder to improve the 

safety and efficiency of “see and avoid” flight through an 

automatic display that informs the pilot of nearby traffic.

Trailing edge. The portion of the airfoil where the airflow 

over the upper surface rejoins the lower surface airflow.

Transcribed Weather Broadcast (TWEB). Meteorological 

and aeronautical data recorded on tapes and broadcast over 

selected NAVAIDs. Generally, the broadcast contains routeoriented data with specially prepared NWS forecasts, inflight 

advisories, and winds aloft. It also includes selected current 

information such as weather reports (METAR/SPECI), 

NOTAMs, and special notices.

Transponder. The airborne portion of the ATC radar 

beacon system.

Transponder code. One of 4,096 four-digit discrete codes 

ATC assigns to distinguish between aircraft.

Trend. Immediate indication of the direction of aircraft 

movement, as shown on instruments.

Tricycle gear. Landing gear employing a third wheel located 

on the nose of the aircraft.

Trim. To adjust the aerodynamic forces on the control 

surfaces so that the aircraft maintains the set attitude without 

any control input.

Trim tab. A small auxiliary hinged portion of a movable 

control surface that can be adjusted during flight to a position 

resulting in a balance of control forces.

Tropopause. The boundary layer between the troposphere 

and the mesosphere which acts as a lid to confine most 

of the water vapor, and the associated weather, to the 

troposphere.

Troposphere. The layer of the atmosphere extending from 

the surface to a height of 20,000 to 60,000 feet, depending 

on latitude.

True airspeed. Actual airspeed, determined by applying a 

correction for pressure altitude and temperature to the CAS.

True altitude. The vertical distance of the airplane above 

sea level—the actual altitude. It is often expressed as feet 

above mean sea level (MSL). Airport, terrain, and obstacle 

elevations on aeronautical charts are true altitudes.

Truss. A fuselage design made up of supporting structural 

members that resist deformation by applied loads. The trusstype fuselage is constructed of steel or aluminum tubing. 

Strength and rigidity is achieved by welding the tubing 

together into a series of triangular shapes, called trusses.

T-tail. An aircraft with the horizontal stabilizer mounted on 

the top of the vertical stabilizer, forming a T.

Turbine discharge pressure. The total pressure at the 

discharge of the low-pressure turbine in a dual-turbine axialflow engine.
G-32

Turbine engine. An aircraft engine which consists of an 

air compressor, a combustion section, and a turbine. Thrust 

is produced by increasing the velocity of the air flowing 

through the engine.

Turbocharger. An air compressor driven by exhaust gases, 

which increases the pressure of the air going into the engine 

through the carburetor or fuel injection system.

Turbofan engine. A fanlike turbojet engine designed to 

create additional thrust by diverting a secondary airflow 

around the combustion chamber.

Turbojet engine. A turbine engine which produces its thrust 

entirely by accelerating the air through the engine.

Turboprop engine. A turbine engine which drives a 

propeller through a reduction gearing arrangement. Most of 

the energy in the exhaust gases is converted into torque, rather 

than using its acceleration to drive the aircraft.

Turboshaft engine. A gas turbine engine that delivers power 

through a shaft to operate something other than a propeller.

Turn-and-slip indicator. A flight instrument consisting 

of a rate gyro to indicate the rate of yaw and a curved glass 

inclinometer to indicate the relationship between gravity and 

centrifugal force. The turn-and-slip indicator indicates the 

relationship between angle of bank and rate of yaw. Also 

called a turn-and-bank indicator.

Turn coordinator. A rate gyro that senses both roll and 

yaw due to the gimbal being canted. Has largely replaced 

the turn-and-slip indicator in modern aircraft.

TWEB. See Transcribed Weather Broadcast.

UHF. See ultra-high frequency.

Ultra-high frequency (UHF). The range of electromagnetic 

frequencies between 962 MHz and 1213 MHz.

Ulitimate load factor. In stress analysis, the load that causes 

physical breakdown in an aircraft or aircraft component during 

a strength test, or the load that according to computations, 

should cause such a breakdown.

Uncaging. Unlocking the gimbals of a gyroscopic instrument, 

making it susceptible to damage by abrupt flight maneuvers 

or rough handling.

Uncontrolled airspace. Class G airspace that has not been

designated as Class A, B, C, D, or E. It is airspace in which 

air traffic control has no authority or responsibility to control 

air traffic; however, pilots should remember there are VFR 

minimums which apply to this airspace.

Underpower. Using less power than required for the purpose 

of achieving a faster rate of airspeed change.

United States Terminal Procedures Publication (TPP).

Booklets published in regional format by the NACO that 

include DPs, STARs, IAPs, and other information pertinent 

to IFR flight.

Unusual attitude. An unintentional, unanticipated, or 

extreme aircraft attitude.

Useful load. The weight of the pilot, copilot, passengers, 

baggage, usable fuel, and drainable oil. It is the basic empty 

weight subtracted from the maximum allowable gross weight. 

This term applies to general aviation aircraft only.

User-defined waypoints. Waypoint location and other data 

which may be input by the user, this is the only GPS database 

information that may be altered (edited) by the user.

V1. See takeoff decision speed.

V2. See takeoff safety speed.

VA. The design maneuvering speed. The maximum speed 

at which full, abrupt control movement can be used without 

overstressing the airframe.

Vapor lock. A problem that mostly affects gasoline-fuelled 

internal combustion engines. It occurs when the liquid fuel 

changes state from liquid to gas while still in the fuel delivery 

system. This disrupts the operation of the fuel pump, causing 

loss of feed pressure to the carburetor or fuel injection system, 

resulting in transient loss of power or complete stalling. 

Restarting the engine from this state may be difficult. The fuel 

can vaporise due to being heated by the engine, by the local 

climate or due to a lower boiling point at high altitude.

Variation. Compass error caused by the difference in 

the physical locations of the magnetic north pole and the 

geographic north pole.

VASI. See visual approach slope indicator.
G-33

VDP. See visual descent point.

Vector. A force vector is a graphic representation of a force 

and shows both the magnitude and direction of the force.

Vectoring. Navigational guidance by assigning headings.

Velocity. The speed or rate of movement in a certain 

direction.

Venturi tube. A specially shaped tube attached to the outside 

of an aircraft to produce suction to allow proper operation 

of gyro instruments.

Vertical axis. An imaginary line passing vertically through 

the center of gravity of an aircraft. The vertical axis is called 

the z-axis or the yaw axis.

Vertical card compass. A magnetic compass that consists of 

an azimuth on a vertical card, resembling a heading indicator 

with a fixed miniature airplane to accurately present the 

heading of the aircraft. The design uses eddy current damping 

to minimize lead and lag during turns.

Vertical speed indicator (VSI). A rate-of-pressure change 

instrument that gives an indication of any deviation from a 

constant pressure level.

Vertical stability. Stability about an aircraft’s vertical axis. 

Also called yawing or directional stability.

Very-high frequency (VHF). A band of radio frequencies 

falling between 30 and 300 MHz.

Very-high frequency omnidirectional range (VOR).

Electronic navigation equipment in which the flight deck 

instrument identifies the radial or line from the VOR station, 

measured in degrees clockwise from magnetic north, along 

which the aircraft is located.

Vestibule. The central cavity of the bony labyrinth of the ear, 

or the parts of the membranous labyrinth that it contains.

VFE. The maximum speed with the flaps extended. The upper 

limit of the white arc.

VFR. See visual flight rules.

VFR on top. ATC authorization for an IFR aircraft to operate 

in VFR conditions at any appropriate VFR altitude.

VFR over the top. A VFR operation in which an aircraft 

operates in VFR conditions on top of an undercast.

VFR terminal area chart. At a scale of 1:250,000, a chart 

that depicts Class B airspace, which provides for the control 

or segregation of all the aircraft within the Class B airspace. 

The chart depicts topographic information and aeronautical 

information including visual and radio aids to navigation, 

airports, controlled airspace, restricted areas, obstructions, 

and related data.

V-G diagram. A chart that relates velocity to load factor. It 

is valid only for a specific weight, configuration and altitude 

and shows the maximum amount of positive or negative lift 

the airplane is capable of generating at a given speed. Also 

shows the safe load factor limits and the load factor that the 

aircraft can sustain at various speeds.

Victor airways. Airways based on a centerline that extends 

from one VOR or VORTAC navigation aid or intersection, 

to another navigation aid (or through several navigation aids 

or intersections); used to establish a known route for en route 

procedures between terminal areas.

Visual approach slope indicator (VASI). A visual aid of 

lights arranged to provide descent guidance information 

during the approach to the runway. A pilot on the correct 

glideslope will see red lights over white lights.

Visual descent point (VDP). A defined point on the final 

approach course of a nonprecision straight-in approach 

procedure from which normal descent from the MDA to the 

runway touchdown point may be commenced, provided the 

runway environment is clearly visible to the pilot.

Visual flight rules (VFR). Flight rules adopted by the 

FAA governing aircraft flight using visual references. VFR 

operations specify the amount of ceiling and the visibility the 

pilot must have in order to operate according to these rules. 

When the weather conditions are such that the pilot can not 

operate according to VFR, he or she must use instrument 

flight rules (IFR).

Visual meteorological conditions (VMC). Meteorological 

conditions expressed in terms of visibility, distance from 

cloud, and ceiling meeting or exceeding the minimums 

specified for VFR.

VLE. Landing gear extended speed. The maximum speed at 

which an airplane can be safely flown with the landing gear 

extended.
G-34

VLO.Landing gear operating speed. The maximum speed for 

extending or retracting the landing gear if using an airplane 

equipped with retractable landing gear.

VMC. Minimum control airspeed. This is the minimum 

flight speed at which a light, twin-engine airplane can be 

satisfactorily controlled when an engine suddenly becomes 

inoperative and the remaining engine is at takeoff power.

VMC. See visual meteorological conditions.

VNE.The never-exceed speed. Operating above this speed is 

prohibited since it may result in damage or structural failure. 

The red line on the airspeed indicator.

VNO.The maximum structural cruising speed. Do not exceed 

this speed except in smooth air. The upper limit of the green 

arc.

VOR. See very-high frequency omnidirectional range.

VORTAC. A facility consisting of two components, VOR 

and TACAN, which provides three individual services: VOR 

azimuth, TACAN azimuth, and TACAN distance (DME) 

at one site.

VOR test facility (VOT). A ground facility which emits a 

test signal to check VOR receiver accuracy. Some VOTs are 

available to the user while airborne, while others are limited 

to ground use only.

VOT. See VOR test facility.

VSI. See vertical speed indicator.

VS0. The stalling speed or the minimum steady flight speed 

in the landing configuration. In small airplanes, this is the 

power-off stall speed at the maximum landing weight in the 

landing configuration (gear and flaps down). The lower limit 

of the white arc.

VS1. The stalling speed or the minimum steady flight speed 

obtained in aspecified configuration. For most airplanes, this 

is the power-off stall speed at the maximum takeoff weight 

in the clean configuration (gear up, if retractable, and flaps 

up). The lower limit of the green arc.

V-tail. A design which utilizes two slanted tail surfaces to 

perform the same functions as the surfaces of a conventional 

elevator and rudder configuration. The fixed surfaces act as 

both horizontal and vertical stabilizers.

VX. Best angle-of-climb speed. The airspeed at which an 

airplane gains the greatest amount of altitude in a given 

distance. It is used during a short-field takeoff to clear an 

obstacle.

VY. Best rate-of-climb speed. This airspeed provides the 

most altitude gain in a given period of time. 

VYSE. Best rate-of-climb speed with one engine inoperative. 

This airspeed provides the most altitude gain in a given 

period of time in a light, twin-engine airplane following an 

engine failure.

WAAS. See wide area augmentation system.

Wake turbulence. Wingtip vortices that are created when 

an airplane generates lift. When an airplane generates lift, 

air spills over the wingtips from the high pressure areas 

below the wings to the low pressure areas above them. This 

flow causes rapidly rotating whirlpools of air called wingtip 

vortices or wake turbulence.

Warm front. The boundary area formed when a warm air 

mass contacts and flows over a colder air mass. Warm fronts 

cause low ceilings and rain.

Warning area. An area containing hazards to any aircraft 

not participating in the activities being conducted in the 

area. Warning areas may contain intensive military training, 

gunnery exercises, or special weapons testing.

WARP. See weather and radar processing.

Waste gate. A controllable valve in the tailpipe of an aircraft 

reciprocating engine equipped with a turbocharger. The valve 

is controlled to vary the amount of exhaust gases forced 

through the turbocharger turbine.

Waypoint. A designated geographical location used for route 

definition or progress-reporting purposes and is defined in 

terms of latitude/longitude coordinates.

WCA. See wind correction angle.

Weather and radar processor (WARP). A device that 

provides real-time, accurate, predictive, and strategic weather 

information presented in an integrated manner in the National 

Airspace System (NAS).

Weather depiction chart. Details surface conditions as 

derived from METAR and other surface observations.
G-35

Weight. The force exerted by an aircraft from the pull of 

gravity.

Wide area augmentation system (WAAS). A differential 

global positioning system (DGPS) that improves the accuracy 

of the system by determining position error from the GPS 

satellites, then transmitting the error, or corrective factors, 

to the airborne GPS receiver.

Wind correction angle (WCA). The angle between the 

desired track and the heading of the aircraft necessary to 

keep the aircraft tracking over the desired track.

Wind direction indicators. Indicators that include a 

wind sock, wind tee, or tetrahedron. Visual reference will 

determine wind direction and runway in use.

Wind shear. A sudden, drastic shift in windspeed, direction, 

or both that may occur in the horizontal or vertical plane.

Winds and temperature aloft forecast (FD). A twice daily 

forecast that provides wind and temperature forecasts for

specific locations in the contiguous United States.

Wing area. The total surface of the wing (in square feet), 

which includes control surfaces and may include wing area 

covered by the fuselage (main body of the airplane), and 

engine nacelles.

Wings. Airfoils attached to each side of the fuselage and are 

the main lifting surfaces that support the airplane in flight.

Wing span. The maximum distance from wingtip to 

wingtip.

Wingtip vortices. The rapidly rotating air that spills over an 

airplane’s wings during flight. The intensity of the turbulence 

depends on the airplane’s weight, speed, and configuration. 

Also referred to as wake turbulence. Vortices from heavy 

aircraft may be extremely hazardous to small aircraft.

Wing twist. A design feature incorporated into some wings 

to improve aileron control effectiveness at high angles of 

attack during an approach to a stall.

Work. A measurement of force used to produce movement.

World Aeronautical Charts (WAC). A standard series of 

aeronautical charts covering land areas of the world at a 

size and scale convenient for navigation (1:1,000,000) by 

moderate speed aircraft. Topographic information includes 

cities and towns, principal roads, railroads, distinctive 

landmarks, drainage, and relief. Aeronautical information 

includes visual and radio aids to navigation, airports, airways, 

restricted areas, obstructions and other pertinent data.

Zone of confusion. Volume of space above the station where 

a lack of adequate navigation signal directly above the VOR 

station causes the needle to deviate.

Zulu time. A term used in aviation for coordinated universal 

time (UTC) which places the entire world on one time 

standard.
G-36
I-1

Index

Airspeed .........................................................................8-2

Airspeed indicator (ASI) ............................... 7-1, 7-8, 10-2

Airspeed tape ...............................................................7-12

Airworthiness certificate ................................................8-7

Airworthiness directives (ADs) ...................................8-12

Air Commerce Act .........................................................1-4

Air data computer (ADC) ............................................7-14

Air masses ..................................................................11-18

Air route surveillance radar (ARSR) ...........................12-2

Air route traffic control center (ARTCC) ....................12-2

Air traffic control (ATC) ........................... 1-6, 13-13, 14-7

Alcohol .......................................................................16-13

Alert areas ....................................................................14-4

Alternator .....................................................................6-28

Altimeter ................................................7-1, 7-3, 7-5, 7-12

Altimeter setting ...........................................................12-7

Altimeter system inspection ...........................................8-9

Altitude ........................................................................11-6

Altitude-induced decompression sickness (DCS) ......16-16

Alto ............................................................................11-17

Ammeter ......................................................................6-30

Aneroid barometer .......................................................11-5

Angle of attack (AOA) ...................................................5-4

Annual inspection ..........................................................8-8

Anti-ice ........................................................................6-37

Antiservo tab ........................................................ 2-6, 5-11

Approach light systems ................................................13-7

Area forecasts (FA) ....................................................12-11

Arm ................................................................................9-5

Assessing risk ..............................................................17-5

Asymmetric loading .....................................................4-27

ATC delays ..................................................................12-5

ATC radar beacon system (ATCRBS) .......................13-14

Atmosphere ................................................. 3-1, 10-2, 11-2

Atmospheric circulation ...............................................11-3

Atmospheric pressure .................................. 3-2, 10-2, 11-3

Atmospheric stability .................................................11-12

Attitude and heading reference system (AHRS) 7-12, 7-20

Attitude indicator ............................................... 7-12, 7-18

Autokinesis ...................................................... 16-7, 16-19

Automated Surface Observing System (ASOS) ......... 12-2

Automated Weather Observing System (AWOS) ...... 12-2

100-hour inspection .......................................................8-9

A

Abbreviated briefing ....................................................12-5

Absolute altitude ............................................................7-6

Accelerate-go distance ...............................................10-28

Accelerate-stop distance ............................................10-28

Adjustable-pitch propeller .............................................6-6

Adjustable stabilizer .....................................................5-11

Advection fog .............................................................11-15

Adverse balance .............................................................9-3

Adverse conditions .......................................................12-5

Adverse yaw ...................................................................5-3

Advisory circular (AC) ................................................1-10

Aeromedical factors .....................................................16-1

Aeronautical charts ......................................................13-3

Aeronautical decision-making .....................................17-1

Aeronautical information manual (AIM) .......................1-9

Ailerons ..........................................................................5-3

Airborne radar ............................................................12-3

Aircraft documents .........................................................8-6

Aircraft engine ...............................................................6-1

Aircraft inspections ........................................................8-8

Aircraft maintenance ......................................................8-8

Aircraft owner/operator responsibilities ......................8-13

Aircraft Owners and Pilots Association (AOPA) ........2-16

Aircraft types and categories .......................................1-12

Airfoil ..................................................................... 3-7, 3-8

Airframe .........................................................................2-7

Airframe systems .........................................................6-25

Airline Deregulation Act of 1978 ..................................1-7

Airline transport pilot ...................................................1-14

Airmen’s Meteorological Information (AIRMET)

.......................................................................... 12-3, 12-12

Airplane Flight Manuals (AFM) ....................................8-1

Airport/facility directory (A/FD) .................................13-3

Airport beacon .............................................................13-6

Airport lighting .................................................. 13-6, 13-9

Airport markings and signs ..........................................13-4

Airport signs.................................................................13-6

Airport surveillance radar ............................................12-3

Airspace .......................................................................14-1
I-2

Automatic decision-making .......................................17-20

Automatic terminal information service (ATIS) ............7-5

Automation ................................................................17-25

Automation management ...........................................17-31

Autopilot ......................................................................5-12

Autopilot systems ......................................................17-27

Aviation forecasts ......................................................12-10

Aviation gasoline (AVGAS) ........................................6-26

Aviation medical examiner (AME) .............................16-2

Aviation routine weather report (METAR) ..... 11-18, 12-6

Aviation safety inspector (ASI) .....................................1-9

Aviation weather reports ..............................................12-6

Axes of an aircraft ........................................................4-11

Axes of rotation ..............................................................5-3

B

Balance ...........................................................................9-2

Balanced field length ..................................................10-28

Balance tabs .................................................................5-11

Barbs ..........................................................................11-12

Basic aerodynamics .......................................................2-2

Basic empty weight ........................................................9-5

Before takeoff ............................................................13-18

Benoist, Tom ..................................................................1-3

Bernoulli, Daniel ............................................................3-7

Bernoulli’s Principle of Differential Pressure ................3-7

Best angle-of-climb speed (VX) .....................................7-9

Best rate-of-climb speed (VY) ........................................7-9

Blade angle ...................................................................4-24

Blocked pitot system ....................................................7-10

Blocked static system ...................................................7-11

Boundary layer ..................................................... 4-4, 4-39

Brakes .................................................................. 2-7, 6-32

Brake horsepower (BHP) ..................................... 6-6, 6-24

Bus bar .........................................................................6-29

C

Cabin pressure control system .....................................6-33

Cabin pressurization system ........................................6-32

Calibrated airspeed (CAS) ................................. 7-8, 10-17

Canard ............................................................................5-7

Cannula ........................................................................6-35

Carbon monoxide (CO) poisoning .............................16-11

Carburetor air temperature gauge ................................6-10

Carburetor heat ...............................................................6-9

Carburetor icing .............................................................6-8

Carburetor systems .........................................................6-7

Castellanus .................................................................11-17

Catastrophic .................................................................17-6

Cayley, Sir George .........................................................1-2

Ceiling ........................................................................11-17

Center of gravity .................................................... 9-2, 9-5

Certificated flight instructor (CFI) ..................... 1-16, 1-20

Certificate of aircraft registration ...................................8-6

CG limits ........................................................................9-5

CG range ........................................................................9-5

Chandelles ....................................................................4-33

Change in lift-off technique .......................................10-27

Charles, Professor Jacques .............................................1-2

Cirrus..........................................................................11-17

Civil Aeronautics Act ....................................................1-5

Civil Aeronautics Authority (CAA) ...............................1-5

Civil Aeronautics Board (CAB) .....................................1-5

Civil airports ................................................................13-1

Class A Airspace ..........................................................14-2

Class B Airspace ..........................................................14-2

Class C Airspace ..........................................................14-2

Class D Airspace ..........................................................14-2

Class E Airspace ..........................................................14-2

Class G Airspace ..........................................................14-3

Climbs and descents ...................................................13-18

Climb performance ......................................................10-6

Climb performance expressed as percent gradient

of Climb .....................................................................10-27

Climb requirements ....................................................10-29

Clouds ............................................................ 11-15, 12-16

Cloud classification ..................................................11-17

Code of Federal Regulations (CFR) ..............................1-7

Cold front ...................................................................11-20

Collision avoidance ....................................................13-17

Combustion ..................................................................6-18

Commercial pilot .........................................................1-14

Compass systems .........................................................7-22

Composites .....................................................................2-9

Compressor stalls .........................................................6-23

Continuous-flow oxygen system ..................................6-36

Control ...........................................................................9-3

Controllability .................................................... 4-13, 4-36

Controlled airspace ............................................ 13-2, 14-2

Controlled firing areas (CFAs) .....................................14-4

Control instruments ......................................................2-12

Convective currents .....................................................11-7

Convective significant meteorological information

 (WST) .......................................................................12-13

Cooling ...........................................................................6-1

Coriolis force ...............................................................11-3

Coriolis illusion ............................................................16-6

Corkscrew effect ..........................................................4-26

Coupled ailerons ............................................................5-4

Crew resource management (CRM) ............................17-4

Critical ..........................................................................17-6

Crosswind and headwind component chart ...............10-24
I-3

Cumulus .....................................................................11-17

Current conditions ........................................................12-5

D

Datum .............................................................................9-5

DECIDE Model .........................................................17-17

Decision-making in a dynamic environment .............17-19

Decision-making process ...........................................17-11

Dehydration ................................................................16-12

Deice system ................................................................6-37

Delta ...............................................................................9-5

Density altitude ....................................3-3, 7-6, 10-3, 11-5

Density altitude charts ................................................10-19

Department of Homeland Security (DHS) .....................1-6

Department of Transportation (DOT) ............................1-6

Deposition ..................................................................11-15

Designated pilot examiner ...........................................1-20

Design maneuvering speed (VA) ...................................7-9

Destination forecast .....................................................12-5

Destination signs ..........................................................13-6

Determining loaded weight and CG ..............................9-7

Deviation ......................................................................7-24

Dew point ....................................................... 11-13, 12-16

Differential ailerons .......................................................5-4

Dihedral ........................................................................4-16

Diluter-demand oxygen systems ..................................6-36

Dip errors .....................................................................7-24

Direction signs .............................................................13-6

Direct User Access Terminal Service (DUATS) .........12-4

Doppler radar ...............................................................12-2

Drag ................................................................. 2-2, 4-2, 4-3

Drugs ..........................................................................16-14

Dual lighting ................................................................13-9

Dutch roll .....................................................................4-18

Dynamic hydroplaning ...............................................10-12

Dynamic stability .........................................................4-13

E

Eddy current damping ..................................................7-26

Electrical ........................................................................6-1

Electrical pulse-demand oxygen system ......................6-36

Electrical system .................................................. 2-7, 6-28

Electronic flight displays (EFD) ............. 2-12, 7-12, 12-18

Elevator .................................................................. 2-5, 5-5

Elevator illusion ...........................................................16-7

Emergency locator transmitter (ELT) ............................8-9

Empennage ............................................................. 2-3, 2-5

Empty-field myopia ...................................................16-18

Engine ............................................................................6-1

Engine cooling systems ................................................6-16

Engine pressure ratio (EPR) .........................................6-22

Engine temperature limitations ....................................6-22

Engine water ingestion ...............................................11-25

Enhanced Situational Awareness ...............................17-31

Environmental control systems ......................................6-1

En Route Flight Advisory Service (EFAS) ..................12-4

En route forecast ..........................................................12-5

Equipment Use ...........................................................17-27

Equivalent airspeed (EAS) .........................................10-17

Equivalent shaft horsepower (ESHP) ..........................6-24

Exhaust gas temperature (EGT) gauge ................ 6-8, 6-22

Exhaust systems ...........................................................6-17

Explosive decompression .............................................6-33

External resources ......................................................17-22

F

FAA Safety Team (FAASTeam) ...................................1-9

Fairings ..........................................................................4-4

False horizon .................................................... 16-7, 16-19

Familiarity ..................................................................17-29

Fansler, P. E. ..................................................................1-3

Fast-moving cold front ...............................................11-21

Fatigue ........................................................................16-12

Featureless terrain illusion ...........................................16-9

Federal Aviation Act of 1958 ........................................1-6

Federal Aviation Administration (FAA) ........................1-6

Federal Aviation Agency (FAA) ...................................1-6

Federal Certification of Pilots and Mechanics ...............1-4

Federal Communications Commission (FCC) . 8-14, 13-11

Field offices ....................................................................1-8

First airmail flight ..........................................................1-4

First license ....................................................................1-4

Fixed-pitch propeller ......................................................6-5

Flameout ......................................................................6-23

Flaperons ........................................................................5-5

Flaps ...............................................................................5-8

Flight controls ........................................................ 2-7, 5-2

Flight control systems ....................................................5-1

Flight instruments ..........................................................7-1

Flight limits ....................................................................8-4

Flight maneuvers ..........................................................4-32

Flight publications .......................................................1-11

Flight school ................................................................1-15

Flight service station ....................................................12-4

Flight Standards District Office (FSDO) .......................1-8

Flight Standards Service (AFS) .....................................1-8

Float-type carburetor ......................................................6-7

Floor load limit ..............................................................9-5

Flux gate compass system ............................................7-20

Fog ................................................................... 11-15, 16-9

Forces in climbs ...........................................................4-21

Forces in descents ........................................................4-22
I-4

Forces in turns ..............................................................4-19

Forecast change group ...............................................12-10

Forecast significant weather .......................................12-10

Forecast sky condition ...............................................12-10

Forecast visibility .......................................................12-10

Forecast wind .............................................................12-10

Foreign object damage (FOD) .....................................6-23

Forming good safety habits ........................................17-16

Four-stroke engines ........................................................6-3

Fowler flaps ....................................................................5-9

Fracto .........................................................................11-17

Free-stream velocity .......................................................4-4

Free directional oscillations .........................................4-18

Friction ...........................................................................3-5

Frise-type ailerons ..........................................................5-4

Fronts .........................................................................11-18

Fuel ................................................................................6-1

Fuel-pump system ........................................................6-25

Fuel contamination .......................................................6-27

Fuel gauges ..................................................................6-25

Fuel grades ...................................................................6-26

Fuel injection system ...................................................6-10

Fuel load .........................................................................9-5

Fuel primer ...................................................................6-25

Fuel selectors ...............................................................6-26

Fuel strainers ................................................................6-26

Fuel systems .................................................................6-25

Fuel tanks .....................................................................6-25

Full authority digital engine control (FADEC) ............6-19

Full temperature accountability .................................10-27

Fuselage .........................................................................2-3

G

General Aviation Manufacturers Association (GAMA) 8-2

Generator ......................................................................6-28

Getting beyond rote workmanship .............................17-29

Global positioning system (GPS) ................................2-16

Graphical METARs ...................................................12-23

Graveyard spiral ...........................................................16-6

Gravity-feed system .....................................................6-25

Ground adjustable tabs .................................................5-11

Ground effect .................................................................4-9

Ground lighting illusions .............................................16-9

Ground power unit (GPU) ...........................................6-28

Gyroscopic action ........................................................4-27

Gyroscopic action ........................................................4-27

Gyroscopic attitude indicators .....................................5-12

Gyroscopic flight instruments ......................................7-14

Gyroscopic principles ..................................................7-15

H

Hail .............................................................................11-24

Handbooks ...................................................................1-10

Hazard ..........................................................................17-4

Hazardous attitudes ......................................................17-4

Hazardous Inflight Weather Advisory (HIWAS) ........12-4

Haze .............................................................................16-9

Heading indicator ............................................... 7-13, 7-20

Heatstroke ..................................................................16-12

Henson, William Samuel ...............................................1-3

High intensity white obstruction lights ........................13-9

High speed flight ..........................................................4-38

High speed flight controls ............................................4-43

High speed stalls ..........................................................4-32

History of ADM ...........................................................17-2

History of flight ..............................................................1-2

History of the Federal Aviation Administration (FAA) 1-3

Histotoxic hypoxia .......................................................16-3

Horizontally opposed engine .........................................6-2

Horizontal situation indicator (HSI) ............................7-13

Human behavior .........................................................17-10

Humidity ....................................................................11-13

Humidity ........................................................................3-3

Hydraulic systems ........................................................6-30

Hydromechanical ...........................................................5-2

Hypemic hypoxia .........................................................16-2

Hypersonic ...................................................................4-38

Hyperventilation ..........................................................16-3

Hypoxia ........................................................................16-2

Hypoxic hypoxia ..........................................................16-2

I

ICAO station identifier ...............................................12-10

Ice .................................................................................4-23

Ice fog ........................................................................11-15

Icing ...........................................................................11-24

Ignition ...........................................................................6-1

Ignition system .............................................................6-14

Illusions ........................................................................16-5

Impact pressure chamber ...............................................7-2

Improbable ...................................................................17-6

Inflight Weather Advisories .......................................12-12

In-line engines ................................................................6-2

In-runway lighting .......................................................13-9

Inches of mercury ........................................................11-4

Inclinometer .................................................................7-18

Indicated airspeed (IAS) ........................... 4-39, 7-8, 10-17

Indicated altitude ............................................................7-6
I-5

Induced drag ........................................................... 4-3, 4-5

Induction ........................................................................6-1

Induction system ............................................................6-7

Information management ...........................................17-30

Information signs .........................................................13-6

Instantaneous vertical speed indicator (IVSI) ................7-7

Instrument check ............................................................7-7

Instrument landing system (ILS) .................................2-12

Intelligent flight control systems (IFCS) ........................5-2

Interference drag ............................................................4-4

Internal resources .......................................................17-20

International Civil Aviation Organization (ICAO)

............................................................................ 3-2, 13-12

International Standard Atmosphere (ISA) .. 3-2, 10-2, 11-5

Interpolation ...............................................................10-19

Inversion ....................................................................11-13

Inversion illusion .........................................................16-7

Isobars ........................................................................11-12

J

Jet-fueled piston engine .................................................6-4

K

Keel effect ....................................................................4-17

Knowledge examination ..............................................1-17

Kollsman window ..........................................................7-4

L

Lags ..............................................................................7-26

Landing ......................................................................10-27

Landing charts ............................................................10-25

Landing gear ..........................................2-3, 2-6, 6-1, 6-31

Landing gear extended speed (VLE) ...............................7-9

Landing gear operating speed (VLO) ..............................7-9

Landing performance ..................................... 10-15, 10-33

Landing strip indicators .............................................13-10

Land and hold short lights ............................................13-9

Lateral stability ............................................................4-16

Lazy eights ...................................................................4-33

leading edge ...................................................................3-8

cuffs ..........................................................................5-10

device .........................................................................5-9

flaps ............................................................................5-9

Leads ............................................................................7-26

Leans, the .....................................................................16-6

Lenticularus ................................................................11-17

Licensed empty weight ..................................................9-5

Lift .......................................................................... 2-2, 4-2

Lift/drag ratio .................................................................4-6

Lightning ....................................................................11-25

Lightning strike protection ...........................................2-11

Light sport aircraft (LSA) .................................... 1-12, 8-7

Likelihood of an event .................................................17-6

Lilienthal, Otto ...............................................................1-3

loadmeter ......................................................................6-30

Load distribution ..........................................................4-36

Local airport advisory ..................................................14-4

Location signs ..............................................................13-6

Longitudinal stability ...................................................4-14

Low-level wind shear .................................................11-11

Low-Level Wind Shear Alert System (LLWAS) ......11-11

Lubrication .....................................................................6-1

M

MacCracken, William P., Jr.,. ........................................1-4

Mach buffet ..................................................................4-42

Mach number ...............................................................4-39

Magnetic compass .............................................. 5-12, 7-22

Magnus, Heinrich Gustav ..............................................3-4

Magnus effect .................................................................3-4

Maintenance entries .....................................................8-11

Managing aircraft automation ....................................17-29

Managing risks ...........................................................17-24

Mandatory instruction signs .........................................13-6

Maneuverability ...........................................................4-13

Manifold absolute pressure (MAP) ................................6-6

Marginal .......................................................................17-6

Maximum landing weight ..............................................9-5

Maximum ramp weight ..................................................9-5

Maximum takeoff weight ...............................................9-5

Maximum weight ...........................................................9-5

Maximum zero fuel weight ............................................9-5

Mean aerodynamic chord (MAC) ........................ 4-12, 9-5

Medical certificate ........................................................16-2

Medical certification requirements ..............................1-16

Mesosphere ..................................................................11-3

Meteorologists ..............................................................12-1

Microjets ......................................................................6-20

Middle ear ....................................................................16-4

Military/Federal government airports ..........................13-1

Military operation areas (MOAs) .................................14-4

Military training routes (MTRs) ..................................14-6

Minimum control speed (VMC) ..................................7-10

Minimum equipment lists (MEL) ..................................8-9

Mitigating risk ..............................................................17-6

Mixture control ..............................................................6-8

Modifier........................................................................12-6

Moisture .....................................................................11-13

Moment ................................................................ 4-12, 9-5

Moment arm ......................................................... 4-12, 9-5

Moment index ................................................................9-5

Monocoque ............................................................ 2-3, 2-8
I-6

Montgolfier, Joseph and Etienne ....................................1-2

Motion sickness .........................................................16-11

Multi-function display (MFD) ................ 2-12, 7-13, 12-18

N

N1 indicator ..................................................................6-22

N2 indicator ..................................................................6-22

National Aeronautics and Space Administration (NASA) .

.............................................................................. 2-16, 5-2

National Airspace System ............................................14-7

National Oceanic and Atmospheric Administration 

(NOAA) .........................................................................3-4

National Security Areas (NSAs) ..................................14-6

National Transportation Safety Board (NTSB) .............1-6

National Weather Service (NWS) ................................12-1

Navigation instruments ................................................2-12

Negative arm ................................................................9-10

Negative dynamic stability ..........................................4-13

Negative static stability ................................................4-13

Negligible .....................................................................17-6

Net thrust ......................................................................6-24

Neutral dynamic stability .............................................4-13

Neutral static stability ..................................................4-13

Newton’s basic laws of motion ......................................3-4

Newton’s First Law of Motion ............................ 3-4, 4-19

Newton’s Second Law of Motion ..................................3-4

Newton’s Third Law of Motion ........................... 3-4, 4-26

Next Generation Weather Radar System (NEXRAD)12-21

Night vision ................................................................16-18

Nimbus .......................................................................11-17

Non-movement area boundary marking ......................13-6

Nondirectional beacon (NDB) .....................................2-12

Notices to Airmen (NOTAM) ................... 1-11, 12-5, 13-3

O

Obstacles to maintaining situational awareness .........17-23

Obstructions on wind ...................................................11-8

Obstruction lights .........................................................13-9

Occasional ....................................................................17-6

Occluded front ...........................................................11-22

Oil systems ...................................................................6-15

OODA loop ................................................................17-16

Operational pitfalls .....................................................17-20

Optical illusions ...........................................................16-9

Original equipment manufacturer (OEM) .....................6-4

Oscillation error ...........................................................7-26

Other information .........................................................12-5

Other markings .............................................................13-5

Outlook briefing ...........................................................12-5

Outside air temperature (OAT) gauge ............... 6-10, 7-26

Oxygen masks ..............................................................6-35

Oxygen systems ...........................................................6-34

P

Parachute jumps .........................................................14-10

Parachute jump aircraft operations ..............................14-6

Parasite drag ...................................................................4-3

PAVE Checklist ...........................................................17-6

Payload ...........................................................................9-5

Pennants .....................................................................11-12

Perceive, Process, Perform (3P) .................................17-14

Perceive, Process, Perform with CARE and TEAM ..17-14

Performance .................................................................10-5

Performance charts .....................................................10-18

Performance data .........................................................10-1

Performance instruments .............................................2-12

Performance requirements .........................................10-27

Performance speeds ...................................................10-17

Pheil, A. C. .....................................................................1-3

Pilot in command (PIC) ...............................................1-14

Pilot’s operating handbook (POH) .................................8-1

Pilot certifications ........................................................1-13

Pilot weather reports (PIREPs) ....................................12-8

Pitch .............................................................................4-11

Pitching ........................................................................4-14

Pitot-static flight instruments .........................................7-1

Placards ..........................................................................8-4

Plain flap ........................................................................5-8

Plan, the ......................................................................17-12

Positive dynamic stability ............................................4-13

Positive static stability .................................................4-13

Postural considerations ................................................16-7

Powerplant ...............................................2-3, 2-7, 6-1, 8-3

Practical examination ...................................................1-18

Precession ....................................................................7-15

Precipitation ................................................... 11-18, 12-16

Precision approach path indicator (PAPI) ....................13-7

Preflight inspections .......................................................8-9

Present weather ..........................................................12-16

Pressure-demand oxygen systems ................................6-36

Pressure-type carburetor ................................................6-8

Pressure altitude ............................................ 3-2, 7-6, 10-3

Pressure change/tendency ..........................................12-16

Pressurized aircraft .......................................................6-32

Preventive maintenance ...............................................8-11

Primary flight controls ...................................................5-2

Primary flight display ...................................................2-12

Primary locations of the FAA ........................................1-8

Primary radar .............................................................13-13

Private airports .............................................................13-1
I-7

Private pilot ..................................................................1-14

Probability forecast ....................................................12-10

Probable .......................................................................17-6

Professional Air Traffic Controllers Organization 

(PATCO) Strike .............................................................1-7

Prohibited areas ............................................................14-3

Propeller .......................................................... 2-7, 6-1, 6-4

Propeller anti-ice ..........................................................6-38

Propeller blade .............................................................4-24

Propeller principles ......................................................4-24

Published VFR routes ..................................................14-6

Pulsating visual approach slope ...................................13-7

Pulse oximeters ............................................................6-37

P-factor ............................................................... 4-26, 4-27

Q

Quesada, General Elwood Richard “Pete” .....................1-6

R

Radar observations .......................................................12-2

Radar summary chart .................................................12-17

Radar traffic advisories ..............................................13-14

Radar Weather Reports (RAREP) ...............................12-9

Radial engines ................................................................6-2

Radiation fog ..............................................................11-15

Radiosonde ...................................................................12-2

Radio communications ...............................................13-11

Radio equipment ........................................................13-12

Range performance ......................................................10-8

Rapid decompression ...................................................6-34

Rate of turn ..................................................................4-30

Reciprocating engines ....................................................6-2

Red obstruction lights ..................................................13-9

Reference datum ............................................................9-5

Refueling procedures ...................................................6-27

Region of reversed command ....................................10-10

Reinforcement of onboard suites ...............................17-29

Relative humidity .......................................................11-13

Remarks .......................................................................12-8

Remote .........................................................................17-6

Remote indicating compass .........................................7-21

Repairs and alterations .................................................8-12

Respect for onboard systems .....................................17-29

Restricted areas ............................................................14-3

Retractable landing gear ..............................................6-31

Rigidity in space ..........................................................7-15

Risk ..............................................................................17-4

Risk management .......................................................17-32

Roll ...............................................................................4-11

Rolling .........................................................................4-16

Rough air ......................................................................4-33

Rudder .................................................................... 5-4, 5-7

Rudder ............................................................................2-6

Ruddervators ..................................................................5-8

Runway and terrain slopes illusion ..............................16-9

Runway centerline lighting system (RCLS) ................13-9

Runway distance remaining signs ................................13-6

Runway edge lights ......................................................13-8

Runway end identifier lights (REIL) ............................13-8

Runway incursion avoidance .....................................13-18

Runway lighting ...........................................................13-8

Runway markings ........................................................13-4

Runway surface and gradient .....................................10-11

Runway width illusion .................................................16-9

S

Safety Program Airmen Notification System (SPANS)

......................................................................................1-12

Satellite ........................................................................12-3

Satellite weather ...........................................................12-3

Sea level pressure .......................................................12-16

Sea smoke ..................................................................11-15

Segmented circle visual indicator system ..................13-10

Semimonocoque ..................................................... 2-3, 2-8

Servicing of oxygen systems .......................................6-37

Severity of an event .....................................................17-6

Shock wave ..................................................................4-40

Shock waves .................................................................4-40

Significant Meteorological Information (SIGMET)

.......................................................................... 12-3, 12-13

Significant weather prognostic charts ........................12-18

Single-engine best rate of climb (VYSE) .......................7-10

Single-pilot resource management ...............................17-4

Sinus problems .............................................................16-4

Situational awareness .................................................17-23

Skidding turn ................................................................4-21

Skin friction drag ...........................................................4-4

Sky condition ...............................................................12-7

Slipping turn ................................................................4-20

Slotted flap .....................................................................5-8

Somatogravic illusion ..................................................16-7

Sources of power ..........................................................7-16

Spatial disorientation ...................................................16-5

Special airworthiness certificate ....................................8-8

Special flight permits ...................................................8-12

Special use airspace .....................................................14-3

Spins .............................................................................4-32

Spiral instability ...........................................................4-18

Split flap .........................................................................5-8

Spoilers ........................................................................5-10

Sport pilot ....................................................................1-14

Sport pilot certificate ....................................................1-12
I-8

Squall line ..................................................................11-23

SRM and the 5P Check ..............................................17-11

Stabilator ........................................................................5-6

Stability ................................................4-13, 4-36, 9-2, 9-3

Stagnant hypoxia ..........................................................16-3

Stalls ................................................................... 4-22, 4-32

Stall speed performance charts ..................................10-26

Standard airworthiness certificate ..................................8-7

Standard briefing ..........................................................12-5

Standard datum plane (SDP) ........................................10-3

Standard empty weight ..................................................9-5

Standard temperature lapse rate ...................................10-2

Standard weights ............................................................9-5

Starting system .............................................................6-18

Static pressure chamber .................................................7-2

Static stability ...............................................................4-13

Station ............................................................................9-5

Stationary front ..........................................................11-22

Station identifier ...........................................................12-6

Steam fog ...................................................................11-15

Straight-and-level flight ................................... 10-5, 13-18

Stratosphere ..................................................................11-3

Stratus ........................................................................11-17

Stress ..........................................................................16-11

Stress management .....................................................17-20

Student pilot .................................................................1-16

Student pilot solo requirements ...................................1-16

Subcomponents of an airplane .......................................2-7

Sublimation ................................................................11-15

Subsonic .......................................................................4-38

Sumps ...........................................................................6-26

Superchargers ..................................................... 6-11, 6-12

Supersonic ....................................................................4-38

Supersonic flow ............................................................4-38

Supplemental type certificate (STC) ............................6-26

Surface analysis chart ................................................12-14

Surface aviation weather observations (METARs) .....12-2

Sweepback ......................................................... 4-17, 4-41

Synopsis .......................................................................12-5

T

T-tail configuration ........................................................5-6

Tachometer ..................................................................7-13

Tailwheel landing gear airplanes .................................6-31

Takeoff .......................................................................10-27

Takeoff charts ............................................................10-19

Takeoff distance .........................................................10-28

Takeoff performance ..................................................10-13

Taxiway centerline lead-off lights ...............................13-9

Taxiway centerline lead-on lights ................................13-9

Taxiway lights ..............................................................13-9

Taxiway markings ........................................................13-5

Temperature ................................................... 11-13, 12-16

Temperature and dew point .........................................12-7

Temporary flight restrictions (TFR) .............................14-6

Terminal aerodrome forecasts (TAF) ........................12-10

Terminal doppler weather radar (TDWR) ...................12-3

Terminal radar service area (TRSA) ................ 13-15, 14-6

Tetrahedron ................................................................13-10

Thermosphere ..............................................................11-3

Thielert, Frank ................................................................6-4

Three-color visual approach path .................................13-7

Thrust .............................................................................2-2

Thrust horsepower (THP) .................................... 6-6, 6-24

Thunderstorms ...........................................................11-22

Tornadoes ...................................................................11-23

Torque ..........................................................................4-26

Torquemeter .................................................................6-22

Touchdown zone lights (TDZL) ..................................13-9

Traffic patterns ...........................................................13-18

Trailing edge ..................................................................3-8

Training operations ....................................................13-18

Transcontinental mail route ...........................................1-4

Transcribed information briefing service (TIBS) ........12-4

Transcribed Weather Broadcast (TWEB) ....................12-4

Transonic ......................................................................4-38

Transponder ...............................................................13-14

Transponder inspection ..................................................8-9

Transport category airplane performance ..................10-27

Trend vectors ...............................................................7-14

Tricycle landing gear airplanes ....................................6-31

Trim systems ................................................................5-10

Trim tabs .............................................................. 2-5, 5-10

Tropopause ...................................................................11-3

Troposphere .................................................................11-2

True airspeed (TAS) ................................. 4-39, 7-8, 10-17

True altitude ...................................................................7-6

Truss structure ................................................................2-8

Turbine engines ............................................................6-20

Turbofan .......................................................................6-20

Turbojet ........................................................................6-20

Turboprop ....................................................................6-20

Turboshaft ....................................................................6-20

Turbosuperchargers ............................................ 6-11, 6-12

Turbulence .................................................................11-24

Turn-and-slip indicator ................................................7-17

Turn coordinator ..........................................................7-17

Turn indicator ..................................................... 7-13, 7-16

Two-stroke engine .........................................................6-3

Types of airports ..........................................................13-1

Type certificate data sheet (TCDS) ................................9-3
I-9

Type of report .................................................. 12-6, 12-10

U

Ultralight ......................................................... 1-12, 14-10

Uncontrolled airport .....................................................13-2

Uncontrolled airspace ..................................................14-3

Understand the platform ............................................17-29

Unmanned free balloons ............................................14-10

Upper air observations .................................................12-2

Upslope fog ................................................................11-15

Useful load .....................................................................9-5

Use of resources .........................................................17-20

V

V-tail ..............................................................................5-8

V1 ...............................................................................10-28

V2 ...............................................................................10-28

VA ...............................................................................10-18

Variable inlet guide vane (VIGV) ................................6-23

Vehicle roadway markings ..........................................13-5

Vertical card magnetic compass ..................................7-26

Vertical speed indicator (VSI) ...................... 7-1, 7-7, 7-13

Vertical stability ...........................................................4-17

Very high frequency (VHF) omnidirectional radio

range (VOR) .................................................................2-12

Very light jets (VLJs) ...................................................6-20

Vestibular illusions ......................................................16-6

Vestibular system .........................................................16-5

VFE .............................................................................10-18

VFS .............................................................................10-28

Vg diagram ...................................................................4-33

Vinci, Leonardo da .........................................................1-2

Visibility .......................................................... 11-18, 12-7

Vision .........................................................................16-17

Visual approach slope indicator (VASI) ......................13-7

Visual glide slope indicators ........................................13-7

Visual illusions ............................................................16-7

VLE .............................................................................10-17

VLO .............................................................................10-18

VLOF ...........................................................................10-28

VMCA ..........................................................................10-28

VMCG ..........................................................................10-28

VNE .............................................................................10-18

VNO ...........................................................................10-18

Vortex ............................................................................4-8

Vortex generation .......................................................13-16

VOR receiver checkpoint marking ..............................13-5

VR ...............................................................................10-28

VS ...............................................................................10-27

VS0 ..............................................................................10-17

VS1 ..............................................................................10-17

VX ...............................................................................10-17

VY ...............................................................................10-17

W

Wake turbulence ................................................ 4-8, 13-15

Warm front .................................................................11-19

Warning areas ..............................................................14-4

Water refraction ...........................................................16-9

Weather .............................................................. 11-1, 12-7

Weather briefings .........................................................12-5

Weather charts ...........................................................12-14

Weather depiction chart .............................................12-16

Weight ............................................ 2-2, 4-2, 4-7, 4-35, 9-1

Weight and balance ......................................................4-35

computations ..............................................................9-6

restrictions ..................................................................9-7

Weight and loading distribution .....................................8-3

Weight control ...............................................................9-1

White arc ........................................................................7-9

Wind ................................................................. 12-6, 12-16

Windscreen anti-ice .....................................................6-38

Winds and temperatures aloft ......................................12-5

Winds and temperature aloft forecast (FD) ...............12-14

Wind direction indicators ...........................................13-10

Wind patterns ...............................................................11-7

Wind shear .................................................................11-11

Wind shifts .................................................................11-22

Wind sock ..................................................................13-10

Winglets .......................................................................3-10

Wings ..................................................................... 2-3, 2-4

Wingtip vortices .............................................................4-8

Workload management ..............................................17-23

Wright, Wilbur and Orville ............................................1-3

WSR-88D NEXRAD radar ..........................................12-2

Y

Yaw ..............................................................................4-11

Yawing .........................................................................4-17

Yaw string ....................................................................7-18

Z

Zero fuel weight ...........................................................9-10

Zulu time ......................................................................12-8
I-10