Aero Academic
Aero Academic
Standardized velocity codes used to identify critical airspeeds for an aircraft, such as best angle-of-climb (Vx) or best rate-of-climb (Vy).
V-speeds are a standardized set of codes, each beginning with V, used across aviation to identify airspeeds significant to the safe operation of an aircraft. They are published in the aircraft's Pilot's Operating Handbook and, for many, marked directly on the airspeed indicator.
Vx is the best angle-of-climb speed — the speed that gains the most altitude over the shortest horizontal distance, used when clearing an obstacle close to the runway. Vy is the best rate-of-climb speed — the speed that gains the most altitude per unit of time, used for a normal climb once clear of obstacles. Vx is slower than Vy, and the two converge at the aircraft's absolute ceiling.
Other frequently tested V-speeds include Vso (stalling speed in the landing configuration), Vfe (maximum flap-extended speed), Vno (maximum structural cruising speed, the top of the green arc), and Vne (never-exceed speed, the red line, which must not be deliberately exceeded in any situation).