General Airspeed Terminology and Symbols

Knots Indicated Airspeed

The speed indicated by the pointer on the airspeed indicator

Knots Calibrated Airspeed

Indicated airspeed corrected for both pitot tube and static port position or error and internal airspeed indicator instrument error

Decision Speed

The highest airspeed on the ground at which, as a result of engine failure or other reasons, the pilot is assumed to have made decision to either continue or reject the takeoff

Take-off Safety Speed

The actual speed of 35 feet above the runway surface as demonstrated in flight during single engine takeoff

Gust Penetration Speed

The maximums speed recommended for flight in rough air

Maximum Flap Extended Speed

The highest speed permissible with wing flaps in a specified position

Maximum Operating Speed

The speed that may not be deliberately exceeded at any time

Minimum Control Speed - Single Engine

The lowest speed at which the aircraft is controllable in flight and in the takeoff configuration with one engine operating at maximum power and the propeller of the other engine feathered

Normal Operating Limit and Maximum Structural Cruising Speed

Never Exceed Speed

A speed that should never be exceeded due to the risk of control surface flutter or structural failure

Maneuvering Speed

The maximum speed for maneuvers involving an approach to a stall condition, or full application of one of the primary flight controls

It is equal to the stalling speed of the aircraft at maximum allowable positive G Load

At or below V_p, the aircraft will stall before flight loads exceed design limitations

At speeds above V_p, design flight load limitations will be exceeded before the aircraft stall

Rotation Speed

The speed at which the pilot initiates a change in the attitude of the aircraft with the intention of leaving the ground

Landing Approach

The speed used for final approach and landing, and also the speed upon which the balked  landing rate of climb and gradient of climb performance charts are based upon

Stalling Speed (or minimum steady flight speed)

The lowest speed at which  the aircraft is controllable

Stalling Speed with a specified configuration at a specified weight

Stalling Speed with a specified flap setting that is other than the landing flap setting

Touchdown Speed

It is 1.05 of stall speed for a specified weight and flap configuration

Best Angle of Climb Speed

The speed that results in the greatest gain of altitude over a given horizontal distance forward

Best Rate of Climb Speed

The speed which results in the greatest gain of altitude within a given period of time

Best Rate of Climb Speed - One Engine Inoperative