V Speeds – the most important speeds in aircraft operations. Vs – stall, Vne – never exceed, Vx and Vy – climb… always remember the correct values for the plane you fly.
Stall (Vs, Vs0)
Vs – stall speed; minimum speed of straight and level flight when aircraft is still controllable. Remeber that banks and G-force increase stall speed (accelerated stall speed is described as Vsacc).
Vs0 – stall speed in landing configuration. Stall speed for straight and level flight with extended flaps and gear. Lower than Vs.
Vs is usually given for Maximum Takeoff Weight – the actual stall speed will be lower. Treat it as a safety margin and do not try your chances at or below Vs.
Maximum speed (Vne, Vfe, VA, Vno)
Vne – never exceed speed. Marked with a red line on your airspeed indicator.
Vfe – maximum flap extended speed. (the end of white arc on airspeed indicator). Check your aircraft manual for information whether it concerns all flaps settings or a specific range of flaps settings. For example Vfe for Cessna 172 is 85 knots (and white arc ends there). But a safe speed for flap extension (the first notch) is 100 or 110 depending on a model. The manual can also specify additional restrictions – for example maximum flaps extended speed may be higher than maximum extension or retraction speed.
VA – design maneuvering speed. The max. speed which allows for a full deflection of control surfaces. Above this speed the G-force caused by a full deflection maneuver may cause structural damage.
Vno – maximum speed for normal operations. The end of green band on airspeed indicator. It’s also the maximum speed in turbulent air.
Climb (Vx & Vy)
Vx – best angle of flight speed. Useful when there are any obstacles on the way. Gives the best altitude gain for the distance traveled.
Vy – best rate of climb speed. The fastest way to climb to desired altitude.
|V1||Takeoff decision speed. Takeoff can not be safely aborted beyond this speed. A multi engine plane should continue the take-off even in an event of engine failure. V1 should be calculated before departure.|
|V2||Takeoff safety speed. The speed which allows for a safe climb with one engine inoperable.|
|VA||Design maneuvering speed. (max. control deflection speed).|
|VB||Design speed for maximum gust intensity.|
|VC||Design cruise speed.|
|VD||Design dive speed.|
|VDF||Demonstrated flight dive speed.|
|VFE||Maximum flap extended speed. (detailed description above).|
|VFTO||Final take-off speed.|
|VH||Maximum speed in level flight at maximum continuous power.|
|VLE||Maximum landing gear extended speed. (max. extension and retraction speed may be lower – VLO).|
|VLO||Maximum landing gear operating speed. (max. extension and retraction speed).|
|VMC||Minimum control speed with one engine inoperable. (red line)|
|Vmcl||Minimum control speed in the landing configuration with one engine inoperative.|
|VMO||Maximum operating limit speed.|
|VMU||Minimum unstick speed.|
|VNE||Never exceed speed.|
|VNO||Maximum structural cruising speed or maximum speed for normal operations.|
|VRef||Landing reference speed / threshold crossing speed.|
|VS0||Stall speed (landing configuration).|
|VS1||Stall speed (specific configuration – for example flaps extended, gear retracted).|
|VSW||Speed at which the stall warning will occur.|
|VX||Best angle of climb speed.|
|VY||Best rate of climb speed.|