1-5
Symbols, Abbreviations, and Terminology
1-5-1
General Airspeed Terminology and Symbols
CAS
Calibrated Airspeed means the indicated airspeed of an aircraft,
corrected for position and instrument error. Calibrated Airspeed
is equal to True Airspeed in standard atmosphere at sea level.
GS
Ground Speed is the speed of an airplane relative to the ground.
IAS
Indicated Airspeed means the speed of an aircraft as shown on
its airspeed indicator.
KCAS
Calibrated Airspeed expressed in knots.
KIAS
Indicated Airspeed expressed in knots. In APEX KIAS is
corrected for position error.
M
Means Mach number. Mach number is the ratio of true airspeed
to the speed of sound.
M
MO
Maximum Operating Limit Speed is the speed limit that may not
be deliberately exceeded in normal flight operations. M is
expressed in Mach number.
TAS
True Airspeed means the airspeed of an airplane relative to
undisturbed air which is the CAS corrected for altitude,
temperature, and compressibility.
V
FE
Maximum Flap Extended Speed is the highest speed
permissible with wing flaps in a prescribed extended position.
V
LE
Maximum Landing Gear Extended Speed is the maximum speed
at which an airplane can be safely flown with the landing gear
extended.
V
LO
Maximum Landing Gear Operating Speed is the maximum
speed at which the landing gear can be safely extended or
retracted.
V
MO
Maximum Operating Speed is the speed limit that may not be
exceed at any time. V is expressed in knots.
V
O
Maximum Operating Maneuvering Airspeed is the maximum
speed at which application of full available aerodynamic control
will not overstress the airplane.
Note
V
O
is defined in accordance with FAR 23 Amendment 45.
V
R
Rotation Speed used for takeoff.
V
S
Stalling Speed or the minimum steady flight speed at which the
airplane is controllable.
V
SO
Stalling Speed or the minimum steady flight speed at which the
airplane is controllable in the landing configuration at maximum
gross weight.
V
S1
Stalling Speed or the Minimum Steady Flight Speed at which the
airplane is controllable in the specified configuration at the
specified weight.
V
X
Best Angle of Climb Speed is the airspeed which delivers the
greatest gain of altitude in the shortest possible horizontal
distance.
Section 1 - General
Symbols, Abbreviations, and Terminology
Pilot's Operating Handbook
Report No: 02406
Issue date: Mar 06, 2020
Page 1-5-1
12-C-A15-00-0105-00A-005A-A
FOR
GENERAL
AND
FAMILIARIZATION
PURPOSES
ONLY
