Suggest a definition.
These definitions come directly from Federal Aviation Regulations parts
1 and
91, unless noted.
- aircraft - large
- means aircraft of more than
12,500 pounds maximum certificated takeoff weight.
- aircraft - small
- means aircraft of 12,500 pounds
or less, maximum certificated takeoff weight.
- airspeed - calibrated
- Indicated airspeed of an aircraft,
corrected for position and instrument error.
Calibrated airspeed is equal to true airspeed
in standard atmosphere at sea level.
- airspeed - indicated
- 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.
- airspeed - true
- means the airspeed of an
aircraft relative to undisturbed air.
- category - aircraft
- As used with respect
to the certification of aircraft, means a grouping of
aircraft based upon intended use or operating limitations. Examples include:
transport; normal; utility; acrobatic; limited; restricted; and provisional.
- category - pilot certification
- As used with
respect to the certification, ratings, privileges, and limitations of pilots,
means a broad classification of aircraft.
Examples include: airplane; rotorcraft; glider; and lighter-than-air.
- ceiling
- the height above the earth's surface of the
lowest layer of clouds or obscuring phenomena that is reported as
"broken," "overcast" or "obscuration" and not classified as "thin"
or "partial".
- CFI
- means Certificated Flight Instructor.
- class - aircraft
- As used with respect to the
certification of aircraft, means a broad grouping of aircraft having similar
characteristics of propulsion, flight or landing. Examples include: airplane;
rotorcraft; glider; balloon; landplane and seaplane.
- class - pilot certification
- As used with respect
to the certification, ratings, privileges, and limitations of airmen,
means a classification of aircraft within a category having similar
operating characteristics. Examples include: single engine; multiengine;
land; water; gyroplane, helicopter; airship; and free balloon.
- controlled airspace
- means an airspace of
defined dimensions within which air traffic control service is provided to
IFR flights and to VFR flights in accordance with the airspace classification.
Note: Controlled airspace is a generic term that covers Class A,
Class B, Class C, Class D, and Class E airspace.
- crewmember
- means a person assigned to
perform duty in an aircraft during flight time.
- day
- means the period of time between the beginning of morning
civil twilight and the end of evening civil twilight. (Implied
by FAR 1.)
- FAR
- Federal
Aviation Regulations, Title 14 of the U.S. Code of Federal Regulations.
- flight level
- means a level of constant atmospheric pressure
related to a reference datum of 29.92 inches of mercury (1013.25 hPa).
Each is stated in three digits that represent hundreds of feet.
For example, flight level 250 represents a barometric altimeter indication
of 25,000 feet; flight level 255, an indication of 25,500 feet.
- flight plan
- means specified information,
relating to the intended flight of an aircraft, that is filed orally or in
writing with air traffic control.
- flight time
- means pilot time that commences when an
aircraft moves under its own power for the purpose of flight and ends
when the aircraft comes to rest after landing.
- flight time - cross-country
- means flight time on any flight
in which the point of departure is a straight-line distance of 92 km (50 Nmi)
from the point of arrival. FAR 61.1(b)(3)(ii)(B)
The FARs are unclear about whether this means the point of first
arrival or all legs of a round-robin flight, but it appears—and
we log it so—that after the first 50 Nmi leg, all subsequent
legs of the same flight count as cross-country time. We would appreciate
your comments on this point.
- flight time - dual
- means flight time during which a
(CFI) is present. A pilot with the proper certificates and ratings for the aircraft
flown may still log pilot in command time while
flying dual.
- flight time - instrument
- A person may
log instrument time only for that flight time when the person operates
the aircraft solely by reference to instruments under actual or simulated
instrument flight conditions. FAR 61.51(g)
- flight time - pilot in command
- A recreational, private, or commercial pilot may log pilot-in-command time
only for that flight time during which that person (i) is the sole manipulator of the
controls of an aircraft for which the pilot is rated; (ii) is the sole occupant of the
aircraft; or (iii) except for a recreational pilot, is acting as pilot in command of an
aircraft on which more than one pilot is required under the type certification of the
aircraft or the regulations under which the flight is conducted.
A student pilot may log pilot-in-command time when the student pilot (i) is the sole
occupant of the aircraft... (ii) has a current solo flight endorsement as required under
FAR 61.87; and (iii) is undergoing training for a pilot certificate or rating. FAR 61.51(e)
- flight time - solo
- A pilot may log as solo flight time only that flight time
when the pilot is the sole occupant of the aircraft. FAR 61.51(d) A supervised
solo is a solo flight in which a CFI observes
the student from the ground while the student conducts traffic
pattern operations.
- IFR
- Instrument Flight Rules,
FAR 91.167 et seq.
An IFR flight is a flight for
which the pilot files an IFR flight plan and conforms to the appropriate Instrument
Flight Rules. It doesn't mean that the pilot can't see the ground,
or that the flight even requires instruments. However, any time the pilot does not
have a visual reference to the ground, IFR applies. Cf. VFR,
MVFR.
- IFR conditions
- means weather conditions below the
minimum for flight under visual flight rules. (Also called "IMC," for
"Instrument Meterological Conditions.")
- METAR
- A meteorological aviation report, formatted according to
the Federal Meteorological
Handbook.
- MSL
- Altitude above mean sea level.
- MVFR
- Marginal Visual Flight Rules. When visibility and ceilings are
close to, but not below, VFR minimums, pilots can still fly for
certain purposes. Usually pilots can only conduct traffic pattern
operations under MVFR.
- night
- means the time between the end of evening
civil twilight and the beginning of morning civil twilight,
as published in the American Air Almanac, converted to local time.
When referring to logged flight time, night means the time beginning one hour after
sunset and ending one hour before sunrise.
- pilotage
- means navigation by visual reference to landmarks.
- pilot in command
- means the person who (1) has final authority
and responsibility for the operation and safety of the flight; (2) has been designated
as pilot in command before or during the flight; and (3) holds the appropriate category,
class, and type rating, if appropriate, for the conduct of the flight.
- special VFR conditions
- (SVFR) mean meteorological conditions that
are less than those required for basic VFR flight in controlled
airspace and in which some aircraft are permitted flight under visual flight rules.
- standard atmosphere
- The combination of temperature and
pressure used as a universal reference, equal to 1013.25 hPa (29.92 in/Hg) at sea level with
a temperature of 15°C (59°F). (dab)
- speed - best angle of climb
- (noted as VX)
means the speed at which the airplane will climb at the steepest angle. (dab)
- speed - best rate of climb
- (noted as VY)
means the speed at which the airplane will climb at fastest rate. (dab)
- speed - flap extended
- (noted as VFE) means
the highest speed permissible with wing flaps in a prescribed extended position. Corresponds
to the upper limit of the white arc on an airspeed indicator.
- speed - ground
- The speed of an aircraft relative to the ground.
- speed - landing gear extended
- (noted as VLE)
means the maximum speed at which an aircraft can be safely flown with the landing
gear extended.
- speed - landing gear operating
- (noted as VLO)
means the maximum speed at which the landing gear can be safely extended or retracted.
- speed - never exceed
- (noted as VNE)
means the maximum speed at which an aircraft can be safely operated. Corresponds
to the upper limit of the yellow arc, and the red line, on an airspeed indicator. (dab)
- speed - normal operating
- (noted as VNO)
means the maximum structural cruising speed of an aircraft. Corresponds to the upper
limit of the green arc on an airspeed indicator. (dab)
- speed - stall
- (noted as VS0)
means the speed at which the airplane stall with flaps down; i.e., the slowest
indicated airspeed the airplane can fly and still remain airborne. Corresponds
to the lower limit of the white arc on an airspeed indicator. (dab)
- speed - stall - clean
- (noted as VS1)
means the speed at which the airplane stall with flaps (and landing gear) up. (dab)
- traffic pattern
- means the traffic flow that is prescribed for
aircraft landing at, taxiing on, or taking off from, an airport.
- twilight - astronomical
- means that period of time when the center of
the sun's disc is higher than 18° below the horizon. Nautical twilight roughly corresponds
to the period beginning 90 minutes before sunrise and ending 90 minutes after sunset.
During this period, the atmosphere
does not scatter any sunlight, making ground-based visual astronomy possible. (dab)
- twilight - civil
- means that period of time when the center of
the sun's disc is higher than 6° below the horizon. Civil twilight roughly corresponds
to the period beginning one half-hour before sunrise and ending one half-hour after sunset. (dab)
- twilight - nautical
- means that period of time when the center of
the sun's disc is higher than 12° below the horizon. Nautical twilight roughly corresponds
to one hour before sunrise to one hour after sunset. (dab)
- VFR
- Visual Flight Rules. In most classes of airspace, VFR operation
requires a specific minimum visibility and ceiling, and requires
the pilot to maintain specific distances from clouds. Cf. IFR,
MVFR.
- visibility - flight
- means the average forward
horizontal distance, from the cockpit of an aircraft in flight,
at which prominent unlighted objects may be seen and identified by day
and prominent lighted objects may be seen and identified by night.
- visibility - ground
- means prevailing horizontal
visibility near the earth's surface as reported by the United
States National Weather Service or an accredited observer.
Submitted by reader D.B.