Aircraft Speeds

GENERAL AIRSPEED TERMINOLOGY AND SYMBOLS
KCAS : Knots Calibrated Airspeed is the indicated airspeed
expressed in knots corrected for position and instrument
error. Knots calibrated airspeed is equal to KTAS in standard
atmosphere at sea level.
KIAS : Knots Indicated Airspeed is the speed shown on the
airspeed indicator and expressed in knots.
KTAS : Knots True Airspeed is the airspeed expressed in knots
relative to undisturbed air which is KCAS corrected for
altitude and temperature.
VA : Maneuvering Speed is the maximum speed at which full or
abrupt control movements may be used.
VFE : Maximum Flap Extended Speed is the highest speed
permissiblewithwing flaps in a prescribed extended position.
VLE : MaximumLanding Gear Extended Speed is themaximum
speed at which an airplane can be safely flown with the
landing gear extended.
VLO : MaximumLandingGearOperating Speed is themaximum
speed at which the landing gear can be safely extended or
retracted.
VMO : Maximum Operating Speed is the speed limit that may not
be deliberately exceeded in normal flight operations.
VR : Rotation Speed is the speed at which rotation is initiated
during takeoff to achieve takeoff safety speed at screen
height.
VSO : Stalling Speed or the minimum steady flight speed at
which the airplane is controllable in the landing configuration.
VS1 : Stalling Speed or the minimum steady flight speed
obtained in a specific configuration.
Vx : Best Angle of Climb Speed is the airspeed which delivers
the greatest gain of altitude in the shortest possible horizontal
distance.
VY : Best Rate of Climb Speed is the airspeed which delivers the
greatest gain in altitude in the shortest possible time.