Definitions Flashcards
1
Q
Absolute Altitude
A
Actual height above the surface of the earth, either land or water
2
Q
Absolute Ceiling
A
The altitude where a particular airplane’s climb rate reaches zero
3
Q
Adiabatic Cooling
A
A process of cooling the air through expansion. For example, as air moves up a slope it expands with the reduction of atmospheric pressure and cools as it expands
4
Q
Adiabatic Heating
A
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.
5
Q
Advection Fog
A
Fog resulting from the movement of warm, humid air over a cold surface
6
Q
Agonic Line
A
Line along which the variation between true & magnetic values is zero
7
Q
Air Density
A
the density of the air in terms of mass per unit volume. Dense air has more molecules per unit volume than less dense air. The density of air decreases with altitude above the surface of the earth & with increasing temperature
8
Q
Air Route Traffic Control Center (ARTCC)
A
A facility established to provide air traffic control service to aircraft operating on IFR flight plans within controlled airspace, principally during the enrollee phase of flight
9
Q
Air traffic Control (ATC)
A
A service provided by the FAA to promote the safe, orderly, and expeditious flow of air traffic
10
Q
Airmass
A
An extensive body of air having fairly uniform properties of temperature and moisture
11
Q
Airmet
A
In-flight weather advisory concerning moderate icing, moderate turbulence, sustained winds of 30 knots or more at the surface, and widespread areas of ceilings less than 1,000 feet and/or visibility less than 3 miles
12
Q
Airport Advisory Area
A
The area within 10 statute miles of an airport where a flight service station is located, but where there is no control tower in operation
13
Q
Airport Surveillance Radar (ASR)
A
Approach & departure control radar used to detect & display an aircraft’s position in the terminal area
14
Q
Alert Area
A
Special use airspace which may contain a high volume of pilot training activities or an unusual type of aerial activity
15
Q
Altimeter
A
A flight instrument that indicates altitude by sensing pressure changes
16
Q
Altimeter Setting
A
The barometric pressure setting used to adjust a pressure altimeter for variations in existing atmospheric pressure and temperature
17
Q
Altitude
A
Height expressed in units of distance above a reference plane, usually above mean sea level or above ground level
18
Q
Angle of Attack
A
The angle between the airfoil’s chord line and the relative wind
19
Q
Annual Inspection
A
Recurring examination of an aircraft that is required to maintain its airworthiness
20
Q
Angle of Incidence
A
The angle between the chord line of the wing and the longitudinal axis of the airplane
21
Q
ARM
A
The distance from the reference datum at which a weight may be located. Used in weight and balance calculations to determine moment
22
Q
Aspect Ratio
A
Span of a wing divided by its average chord
23
Q
Automated Surface Observation System (ASOS)
A
Weather reporting system which provides surface observations every minute via digitized voice broadcasts and printed reports
24
Q
Automated Weather Observing System (AWOS)
A
Automated weather reporting system consisting of various sensors, a processor, a computer-generated voice subsystem, and a transmitter to broadcast weather data
25
Automatic Direction Finder (ADF)
An aircraft radio navigation system which senses and indicates the direction to an L/MF nondirectional radio beacon (NDB) or commercial broadcast station
26
Automatic Dependent Surveillance-Broadcast (ADS-B)
An Aircraft surveillance system in which appropriately equipped aircraft transmit their GPS positions to ATC, and download weather and traffic information to the cockpit through a data link
27
Automatic Terminal Information Servie (ATIS)
The continuous broadcast of recorded non control information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information
28
Basic Radar Service
A radar service for VFR aircraft which includes safety alerts, traffic advisories, and limited radar vectoring, as well as aircraft sequencing at some terminal locations
29
Bearing
The horizontal direction to or from any point, usually measured clockwise from true north, magnetic north, or some other reference point, through 360 degrees
30
Best Angle-of-Climb Airspeed (VX)
The airspeed which produces the greatest gain in altitude for horizontal distance traveled
31
Best Rate-of-Climb Airspeed (Vy)
The airspeed which produces the maximum gain in altitude per unit of time
32
Blast Pad
An area associated with a runway where propeller blast can dissipate without creating a hazard to others. It cannot be used for landing, takeoffs, or taxiing
33
Bracketing
A navigation technique which uses a series of turns into a crosswind to regain and maintain the sesired course
34
Calibrated Airspeed (CAS)
Indicated airspeed of an aircraft, corrected for installation and instrument errors
35
Calibrated Altitude
Indicated altitude corrected to compensate for instrument error
36
Camber
The curve of an airfoil section from the leading edge to the trailing edge
37
Category
(1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a broad classification of aircraft (airplane, rotorcraft, glider, lighter-than-air, and powered lift)
(2) As used with respect to the certification of aircraft, means a grouping of aircraft, means a grouping of aircraft by intended use or operating limitations (transport, normal, utility, acrobatic, limited, restricted, experimental and provisional)
38
Ceiling
The height above the earth's surface of the lowest layer of clouds which is reported as broken or overcast or the veritical visibility into an obscuration
39
Center of Gravity (CG)
The theoretical point where the entire weight of the airplane is considered to be concentrated
40
Center of Pressure
A point along the wing chord line where lift is considered to be concentrated
41
Centrifugal Force
An apparent force, that opposes centrpetal force, resulting from the effect of inertia during a turn
42
Centripetal Force
A center-seeking force directed inward toward the center of rotation created by the horizontal component of lift in turning flight
43
Chord
An imaginary straight line between the leading and trailing edges of an airfoil section
44
Class
(1) As used with respect to the certification, ratings, privileges, and limitations of airman, means a classification of aircraft within a category having similar operating characteristics (single-engine land, multi-engine land, single-engine sea, multi-engine sea, gyroplane, helicopter, airship, and free balloon)
(2) As used with respect to certification of aircraft means a broad grouping of aircraft having similar characteristics of propulsion, flight, or landing (airplane, rotorcraft, glider, ballon, landplane, and seaplane)
45
Class A Airspace
Controlled air-space covering the 48 contiguous United States and Alaska, within 12 nautical miles of the coasts, from 18,000 feet MSL up to and including FL600, but not including airspace less than 1,500 feet AGL
46
Class B Airspace
Controlled airspace designated around certain major airports, extended from the surface or higher to specified altitudes where ATC provides radar separation for all IFR and VFR aircraft. For aperations in Class B airspace, all aircraft must receive an ATC clearance to enter, and are subject to the rules and pilot/equipment requirements listed in FAR part 91
47
Class C Airspace
Controlled airspace surrounding designated airports where ATC provides radar vectoring and sequencing for all IFR and VFR aircraft. Paricipation is mandatory, and all aircraft must establish and maintain radio contact with ATC, and are subject to the rules and pilot/equipment requirements listed in FAR part 91
48
Class D Airspace
Controlled airspace around at least one primary airport which has an operating control tower. Aircraft operators are subject to the rules and equipment requirements specified in FAR Part 91
49
Class E Airspace
Controlled airspace which covers the 48 contguous United States and Alaska, within 12 nautical miles of the coasts, from 14,500 feet MSL up to but nor including 18,000 feet MLS but not including airspace less than 1,500 feet AGL.
Class E airspace also includes Federal airways, with a floor of 1,200 feet AGL of higher, as well as the airspace from 700 feet or more above the surface designated in conjunction with an airport which has an approved instrument approach procedure.
50
Class G Airspace
Airspace that has not been designated as Class A, B, C, D, or E and within which air traffic control is not exercised
51
Clear Air Turbulance (CAT)
While CAT is often encountered near the jet stream in clear air, it also may be present at lower altitudes and in non-convective clouds
52
Clearing Turns
Turns consisting of at least a 1800 change in direction allowing a visual check of the airspace around the airplane to avoid conflicts while maneuvering
53
Cold Front
The boundry between two airmasses where cold air is replacing warm air
54
Common Traffic Advisory Frequency (CTAF)
A frequency designed for the purpose of carrying out airport advisory practices while operating to or from an uncontrolled airport. The CTAF may be a UNICOM, MULTICOM, FSS, or tower frequency and it is identified in appropriate aeronautical publications
55
Compass Heading
Aircraft heading read from the compass heading is derived by applying correction factors for variation, deviation, and wind to true course
56
Complex Airplane
An airplane with retractable landing gear, flaps, and a controllable-pitch propeller
57
Condensation
A change of state of water from a gas (water vapor) to a liquid
58
Condensation Nuclei
Small particles of solid matter in the air on which water vapor condenses
59
Cone of Confusion
The cone-shaped area above a VOR station in which there is no signal and the TO/From flag momentarily flickers to OFF (or a similar idication)
60
Cones
The cells concentrated in the center of the retina which provide color cision and sense fine detail
61
Controlled Airport
An airport which has an operating control tower, sometimes called a tower airport
62
Controlled Airspace
Airspace designated as Class A, B, C, D or E, within which some or all aircraft may be subject to air traffic control
63
Convection
A circulation process caused by unequal air density which results from heating inequities
64
Convective Sigmet
A weather advisory concerning convective weather sifnificant to the safety of all aircraft. Convective SIGMET's are issued for tornadoes, lines of thunderstorms, thunderstorms over a wide area, embedded thunderstorms, wind gusts to 50 knots or greater and/or hail 3/4 inch in diameter or greater
65
Conventional Landing Gear
Two main wheels located on either side of the fuselage and a third wheel, the tail wheel, positioned at the rear of the airplane.
66
Coordinated Universal Time (UTC)
A method of expressing time which places the entire world on one time standard. UTC also is referred to as Zulu time
67
Coriolis Force
A deflective force that is created by the difference in rotational velocity between the equator and the poles of the earth. It deflects air to the right in the northern hemisphere and to the left in the southern hemisphere.
68
Course
The intended or sesired direction of flight in the horizontal plane measured in degrees from true or magnetic north
69
Crosswind
A wind which is not parallel to a runway or the path of an aircraft
70
Crosswind Component
A wind component which is at a right angle to the runway or the flight path of an aircraft
71
Dead Reckoning
A type of nacigation based on the calculations of time, speed, distance, and direction
72
Density Altitude
Pressure altitude corrected for nonstandard temperature
73
Deposition
The direct transformation of a gas to solid state, where the liquid state is bypassed
74
Depressants
Drugs which reduce the body's functioning usually by lowering blood pressure, reducing mental processing, and slowing motar and reaction responses
75
Detonation
An uncontrolled, explosice ignition of the fuel/air mixture within the cylinder's combustion chamber
76
Deviation
A compass error caused by magnetic disturbances from electrical and metal components in the airplane. The correction for this error is despluaed on a compass correction ard placed near the magnetic compass in the airplane
77
Dewpoint
The temperature at which air reaches a state where it can hold no more water
78
Dihedral
The upward angle of an airplane's wings with respect to the horizontal. Dihedral contributes to the lateral stability of an airplane
79
Directional Stability
Stability about the vertical axis
80
Displaced Threshold
When the landing area begins at a point on the runway other than the disignated beginning of the runway
81
Distance Measuring Equipment (DME)
Equipment (airborne and ground) to measure, in nautical miles, the slant range distance of an aircraft from the navigation aid
82
Drag
A backward, or retarding, force which opposes thrust and limits the speed of the airplane
83
Emergency Locator Transmitter (ELT)
A battery-operated radio transmitter attached to the aircraft structure which transmits on 121.5 MHz and 243.0 MHz. It aids in locating downed aircraft
84
Empennage
The section of the airplane which consits of the veritcal stabilizer, the horizontal stabilizer, and the associated control surfaces.
85
Empty Field Myopia
The normal tendency of the eye to focus at only 10 to 30 feet when looking into a field devoid of objects, contrasting colors, or patterns
86
Evaporation
The transformation of a liquid to gaseous state, such as the change of water to water vapor
87
Flight Restricted Zone (FRZ)
Airplane in which general aviation flight is generally prohibited
88
Flight Service Station (FSS)
An air traffic service facility that provides a variety of services to pilots, including weather briefings, opening and closing flight plans, and search and rescue operations
89
Freezing Level
A level in the atmosphere at which the temperature is 320F (0oC)
90
Front
The boundry between two different airmasses
91
Fuselage
The cabin or cockpit, is located in the fuselage. It may also provide room for cargo and attachment points for other major airplane components
92
Global Positioning System (GPS)
A satellite-based radio positioning, navigation, and time-transfer system
93
Great Circle
The largest circle which can be drawn on the earth's surface. A great circle's plane must pass through the center of the earth dividing it into two equal parts
94
Ground effect
A usually beneficial influence on aircraft performance which occurs while you are flying close to the ground. It results from a reduction in upwash, downwash, and wingtip vortices which provide a corresponding decrease in induced drag
95
Groundspeed (GS)
Speed of the aircraft in relation to the ground
96
Hazardous In-Flight Weather Advisory Service (HIWAS)
Contnuous recordings of hazardous weather information broadcast over selected VORs
97
Heading
The direction in which the longitudinal axis of the airplane points with respect to true or magnetic north. Heading is equal to course plus or minus any wind correction angle
98
Headwind Component
That part of the wind which acts directly on the front of the aircraft and decreases its groundspeed
99
Hectopascal (hPa)
The metric equicalent of a millibar (1 hPa = 1 mb
100
High Performance Airplane
An airplane having more than 200 horsepower
101
Homing
A method of navigation to an NDB by holding a zero relative bearing
102
Humidity
Water vapor content in the air
103
Hyperventilation
The excessive ventilation of the lungs caused by very rapid and deep breathing which results in an excessive loss of carbon dioxide from the body
104
Hypoxia
The effects on the human body of an insufficient supply of oxygen
105
Indicated Airspeed (IAS)
The speed of an aircraft as shown on the airspeed indicator
106
Indicated Altitude
The altitude shown by an altimeter set to the current altimeter setting
107
Induced Drag
That part of total drag which is created by the production of lift. Induced drag increases with a decrease in airspeed
108
Instrument Flight Rules (IFR)
rules that govern the procedure for conducting flight in weather conditions below VFR weather minimums. The term IFR also is used to define weather conditions and the type of flight plan under which an aircraft is operating
109
International Standard Atmosphere (ISA)
Standard atmospheric conditions consisting of a temperature of 590F (150C), and a barometric pressure of 29.92 in. Hg. (1013.2 mb) at sea level. ISA values can be calculated for various altitudes using standard lapse rates
110
Inversion
An increase in temperature with altitude
111
ISOBAR
A line which connects points of equal barometric pressure
112
Isogonic Lines
Lines on charts that connect points of equal magnetic variation
113
Jeppesen Information Services
A subscription service for pilots which provides revisions for several flight information publications including the Jeppesen AIM, Jeppesen FARs for Pilots, the Jeppensen Airport Directory, JeppGuide, and the GPS/LORAN Coordinate Directory
114
Jet Stream
A narrow band of winds with speeds of 100 to 200 m.p.h. occurring between approximately 32,000 and 49,000 feet
115
Katabatic Wind
Any downslope wind usually stronger than a mountain breeze. A katabatic wind can be either warm or cold
116
Land Breeze
A coastal breeze blowing from land to sea caused by temperature difference when the sea surface is warmer than the adjacent land. The land breeze usually occurs at night and alternates with a sea breeze which blows in the opposite direction by day
117
Lapse Rate
The rate of decrease of an atmospheric variable with altitude
118
Lateral Stability
Stability about the longitudinal Axis
119
Latitude
Measurment north or south of the equator in degrees, minutes, and seconds. Lines of latitude are also called parallels
120
Lift
An upward force created by the effect of airflow as it passes over and under the wing
121
Load Factor
The ratio of the load supported by the airplane's wings to the actual weight of the aircraft and its contents
122
Local Airport Advisory (LAA)
Advisory service provided to pilots by an FSS at airports without an operating control tower. Information includes known traffic and weather conditions
123
Long Range Navigation (LORAN)
A navigational system by which lines of position are determined by measuring the differences in the time of reception of synchronized pulse signals from fixed transmitters
124
Longitude
Measurement east or west of the Prime Meridian in degrees, minutes, and seconds. Lines of longitude are also called meridians. The Prime Meridian is 00 longitude and runs through Greenwich, England
125
Longitudinal Stability
Stability about the lateral axis. A disirable characteristic of an airplane whereby it tends to return to its trimmed angle of attack after desplacement
126
Magnetic Bearing
The magnetic course you would fly to go direct to a NDB station
127
Magnetic Course
True course corrected for magnetic variation
128
Magneto
A self-contained, engine-driven unit that supplies electrical current to the spark plugs which is completely independent of the airplane's electrical system. Normally there are two magnetos per engine
129
Maneuvering Speed (VA)
The maximum speed at which you can use full, abrupt control movment without overstressing the airframe
130
Mayday
International radio destress signal. When repeated three times, it indicates imminent and grave danger and that immediate assistance is requested
131
Mean Sea Level (MSL)
The average height of the surface of the sea for all stages of tide
132
Mesophere
A Layer of the atmosphere above the stratosphere
133
Microburst
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 horizantal scale, an intense microburst could induce wind speeds greater than 100 knots and downdrafts as strong as 6,000 feet per minute
134
Military Operations Area (MOA)
Special use airspace of difined verticle and lateral limits established to help VFR traffic identify locations where military activities are conducted
135
Military Training Route (MTR)
Route depicted on an aeronautical chart for the conduct of military flight training at speeds above 250 knots
136
MILLIBAR (mb)
A unit of atmospheric pressure equal to a force of 1,000 dynes per square centimeter
137
Minimum Equipment List
A document provided by an aircraft manufacturer or created by an operator and approved by the FAA, that lists the equipment that may be inoperative for a flight based on the conditions of that flight
138
Moment
A measurment of the tendency of a weight to cause ratation at the fulcrum
139
Mountain Breeze
A downslope wind flow at night, caused by the cooling of the air at higher elevations
140
MULTICOM
A frequency (122.9 MHz) for pilots to use as a common traffic advisory frequency to self announce their positions and intentions at airports that don't have a tower, an FSS or a UNICOM
141
Notice to Airmen (NOTAM)
A notice containing time-critical information which is either of a temporary nature or is not known far enough in advance to permit publications on aeronautical charts or other operational publications
142
Obstruction Light
A light, or one of a group of lights, usually red or white, mounted on a surface structure or natural terrain to warn pilots of the presence of a flight hazard
143
Occluded Front
A frontal occlusion occurs when a fast-moving cold front catches up to a slow-moving warm front. The difference in temperature within each frontal system is a major factor in ditermining whether a cold or warm front occlusion occurs
144
Orographic
Associated with or induced by the presence of rising terrain, such as orographic lifting
145
Parasite Drag
That part of total drag created by the form or shape of airplane parts. Parasite drag increases with an increase in airspeed
146
Pilot controlled Lighting (PCL)
Runway lighting systems which are controlled by keying the aircraft's microphone on a specific frequency
147
Pilot in Command (PIC)
The pilot responsible for the operation and safety of an aircraft
148
Pilot Weather Report (PIREP)
A report, generated by pilots, concerning meteorological phenomena encountered in flight
149
Pilotage
Navigation by visual landmarks
150
Precession
The tilting or turning of a gyroscope in response to external forces causing slow drifting and erroneous indications in gyroscopic instruments
151
Preignition
Occurs when the fuel/air mixture is ignited in advance of the normal timed ignition and is usually caused by a residual hotspot in the cylinder
152
Pressure Altitude
Height above the standard pressure level of 29.92 in. Hg. Obtained by setting 29.92 in the barometric pressure window and reading the altimeter
153
Prevailing Visibility
The greatest horizontal visibility throughout at least half the horizon
154
Preventive Maintenance
Minor service that pilots, without an available mechanic certificate are allowed to perform on an aircraft
155
Prohibited Area
Airspace of defined dimensions identified by an area on the surface of the earthwithin which the flight of aircraft is prohibited
156
Radar Advisory
Information or advice provided to pilots based on radar observations
157
Radar Contact
Term used by ATC to advise pilot that the aircraft is identified on radar
158
Radar Vector
A heading issued by a radar controller to the pilot of an aircraft to provide navigational guidance
159
Radial
A navigational signal generated by a VOR or VORTAC, measured as a magnetic bearing from the station
160
Reference Datum
An imaginary vertical plane from which all horizontal distances are measured for balance purposes
161
Relative Bearing
Angular difference between the airplane's langitudinal axis and a straight line drawn from the airplane to the station. It is measured clockwise from the airplane's nose
162
Relative Humidity
The actual amount of moisture in the air compared to the total that could be present at that temperature
163
Restricted Area
Disignated special use airspace within which aircraft flight, while not prohibited, is subject to restrictions
164
Retina
The photosensitive portion of the eye which is connected to the optic nerve and contains cells called rods and cones
165
Retractable Gear
A Pilot controllable landing gear system, whereby the gear can be stowed alongside or inside the structure of the airplane during flight
166
Rigidity in Space
The prinicple that a wheel with a heavily weighted rim spun rapidly will remain in a fixed position in the plane in which it is spinning
167
Rods
The cells concentrated outside of the foveal area whcih are sensitive to low light and not to color
168
Runway Gradient
The amount of change in elevation over the length of the runway
169
Runway Incursion Hotspot
A charted location at an airport where a heightened risk of a runway incursion exists
170
Runway Visual Range
An instrumentally derived value representing the horizontal distance a pilot in a moving aircraft should see down the runway
171
Safety Alert
An alert issued by an ATC radar faciliry when an aircraft under its control is in unsafe proximity to terrain, obstruction, or other aircraft
172
Saturated Air
Air Containing the maximum amount of water vapor it can hold at a given temperature (100% relative humidity)
173
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 which blows in the opposite direction at night
174
Sectional Chart
Most commonly used chart for VFR flight. Each chart covers 60 to 80 of longitude and approximately 40 of latitude and is given the name of a primary city within its coverage. The scale of a sectional chart is 1:150,000
175
Segmented Circle
A set of visual indicators which provide traffic pattern information at airports without operating control towers
176
Service Ceiling
The maximum height above mean sea level, under normal conditions, at which a given airplane is able to maintain a rate of climb of 100 feet per minute
177
SIGMET
An in-flight advisory which is considered significant to all aircraft. SIGMET criteria include severe icing, severe and extreme turbulence, duststorms, sandstorms, volcanic eruptions, and volcanic ask lowering visibility to less than three miles
178
Skid
A flight condition in which the rate of turn is too great for the angle of bank
179
Slip
A flight condition in which the rate of turn is too slow for the angle of bank
180
spatial Disorientation
A feeling of balance instability caused by a conflict between the information relayed by your central vision, and your peripheral vision
181
Special Flight Rules Area (SFRA)
Airspace in which additional requirements or restrictions to flight may be imposed beyond what would normally be appropriate for the class of airspace collocated with the area
182
Special Use Airspace
Defined air-space areas where aircraft operations may be limited. Examples include: alert area, controlled firing area, military operations area, prohibited area, restricted area, and warning area.
183
Special VFR Clearance
An ATC clearance which allows you to operate within the lateral boundaries of the surface areas of Class B, C, D, or E airspace when the ceiling is less than 1,000 feet AGL and/or visibility is below 3 statute miles. While operating under special VFR, you must maintain 1 statute mile visibility and remain clear of clouds
184
Spin
An aggravated stall which results in the airplane descending in a helical, or corkscrew path
185
Squall Line
A continuous line of non-frontal thunderstorms
186
Stall
A rapid decrease in lift cause by the seperation of airflow from the wing's surface brought on by exceeding the critical angle of attack
187
Standard Lapse Rate
For 1,000 feet of altitude in the lower atmosphere (below 36,000 feet) the standard pressure lapse rate is 1.00 in. Hg. and the standard temperature lapse rate is 20C (3.50F)
188
Stationary Front
A boundry between two airmasses which are relatively balanced
189
Stimulants
Drugs which excite the central nervous system and produce an increase in alertness and activity
190
Stopway
An area beyond the take-off runway which is designed to support an airplane during an aborted takeoff without causing structural damage to the airplane. It cannot be used for takeoff, landing or taxiing
191
Stratosphere
The first layer above the tropapause extending to a height of approximately 160,000 feet, with a composition much like the troposphere
192
Sublimation
Process by which a solid is changed to a gas without going through the liquid state
193
Supercooled Water Droplets
Water droplets that have been cooled below the freezing point, but are still in a liquid state
194
Tailwind
Any wind more than 900 from the magnetic heading of the runway
195
Tailwind Component
That part of the wind which acts directly on the rear of the aircraft and increases its groundspeed
196
Telephone Information Briefing Service (TIBS)
Telephone recording of area and/or route meteorological briefings, airspace procedures, and special aviation-oriented announcements
197
Terminal Radar Service Area (TRSA)
Airspace urrounding designated airports in which ATC provides radar vectoring, sequencing, and separation for all IRF aircraft and participating VFR aircraft
198
Terminal VFR Radar Service
A national program which extends the terminal radar services for IFR aircraft to VFR aircraft
199
Tetrahedron
Device used as a landing direction indicator, usually at nontowered airports. The small end points into the wind, or in the general direction of landing
200
Thermosphere
The area of the atmosphere above the mesosphere
201
Threshold
The beginning of the landing area of the runway
202
Thrust
A forward force which propels the airplane through the air
203
Total Drag
The sum of parasite and induced drag
204
Track
The actual flight path of an aircraft over the ground. Also called ground track
205
Tracking
Flying a desired course to or from a station using a sufficient wind correction, if necessary
206
Taffic Advisories
Advisories issued to alert a pilot to other known or abserved air traffic whcih may be in such proximity to their position or intended route of flight as to warrant their attention
207
Traffic Pattern
The traffic flow that is prescribed for aircraft landing and taking off from an airport. The usual components are the departure, crosswind, downwind, and base legs; and the final approach
208
Transcribed Weather Broadcast (TWEB)
A continuous recording of weather and aeronautical information broadcast over selected NDB or VOR stations
209
Transponder
An electronic device aboard the airplane that enhances an aircraft's identity on an ATC radar screen
210
Tricycle Gear
Two main wheels located on either side of the fuselage and a third wheel, the nosewheel, positioned on the nose of the airplane
211
Tropopause
An area at an average altitude of 36,000 feet which acts as a lid to confine most of the water vapor, and the associated weather, to the troposphere
212
Troposphere
The layer of the atmosphere extending from the surface to an average altitude of about 36,000 feet
213
True Airspeed (TAS)
The speed at which an aircraft is moving relative to the surrounding air
214
True Altitude
The actual height of an object above mean sea level
215
True Course (TC)
The intended or desired direction of flight as measured on a chart clockwise from true north
216
True Heading (TH)
The direction the longitudinal axis of the airplane points with respect to tru north. True heading is equal to true course plus or minus any wind correction angle
217
Uncontrolled Airport
A non-towered airport where control of VFR traffic is not exercised
218
Uncontrolled Airspace
Airspace disignated as Class G airspace within which air traffic control is not exercised
219
UNICOM
A nongovernment communications facility which may provide airport information at certain airports
220
Usable Fuel
The amount of fuel available during flight
221
Useful Load
The difference between the basic empty weight of the airplane and the maximum weight allowed by teh manufacturer's specification
222
Valley Breeze
An upslope wind flow caused by the heating of the mountain slope which warms the adjacent air
223
Vapor Lock
A condition in which it may be difficult, or impossible, to restart the engine. Vapor lock may occur as a result of running a fuel tank completely dry allowing air to enter the fuel system. On fuel injected engines the fuel may become so hot it vaporizes in the fuel line, not allowing the fuel to reach the cylinders
224
Variation
The angular difference between true north and magnetic north; indicated on charts by isogonic lines
225
VFR Cruising Altitude
When flying above 3,000 feet AGL on magnetic headings from 00 to 1790 you must fly at odd thousand-foot altitudes plus 500 feet and on headings from 1800 to 3590 you are required to fly at even thousand plus 500 feet up to the flight levels
226
Victor Airway
An airway system based on the use of VOR facilities
227
Visual Flight Rules (VFR)
Rules which specify minimum cloud clearance and visibility requirements for flight. The term VFR also is used to define weather conditions and the type of flight plan under which an aircraft is operating
228
Visual Purple
Another term for rhodopsin, the chemical created by the rods that provides a perception of dim light
229
VOR
Ground-based navigational system consisting of very high frequency omnidirectional range (VOR) stations which provide course guidance
230
Warm Front
The boundary between two airmasses where warm air is replacing cold air
231
Warning Area
Airspace of defined dimensions, extending from three nautical miles outward from the coast of the United States, which contains activity that may be hazardous to nonparticipating aircraft
232
Weight
A downward force caused by gravity. Weight opposes lift
233
Wind correction Angle (WCA)
The angular difference between the heading of the airplane and the course
234
Wind Shear
A sudden, drastic shift in wind speed, direction, or both that may occur in the vertical or horizontal plane
235
Wingtip Vortices
Spirals of air created by an airfoil when generating lift. Vortices from medium to heavy aircraft may be extremely hazardous to small aircraft
236
World Aeronautical Chart (WAC)
Similar to a sectional chart, but with a scale ot 1:1,000,000 provides less detail and is best suited for flight planning
237
Zulu Time
A term used in aviation for coordinated universal time (UTC) which places the entire world on one time standard
