Description

V-speeds are standard terms used to defineairspeeds important or useful to the operation of all aircraft(including fixed-wing aircraft, gliders, autogiros, helicopters,and dirigibles)
These speeds are derived from data obtained by aircraft designersand manufacturers during flight testing and verified in mostcountries by government flight inspectors during aircrafttype-certification testing.
Using them is considered a best practice to maximize aviationsafety and aircraft performance.
The speeds are specific to a particular model of aircraft, and areexpressed in terms of the aircraft's indicated airspeed, so thatpilots may use them directly, without having to apply correctionfactors.
Proper display of V speeds is an airworthiness requirement fortype-certificated aircraft in most countries.