CulturAiles-Knowledge-V speeds

The human operator, the least reliable element of an aerodyne, but the most essential...!
(Frank Caron)

Night approach for the RWY13 on the former Hong kong Airport Kai Tak

Beech 1900D with white background clouds

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Aviation V speeds

V1	Critical engine failure recognition speed V1 is the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff with only the remaining engines. Any problems after V1 are treated as inflight emergencies. In the case of a balanced field takeoff, V1 is the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance and the minimum speed at which the takeoff can be continued and achieve the required height above the takeoff surface within the takeoff distance. In this context, V1 is the takeoff decision speed. Other presentation: V1 is the maximum speed where an acyion must occur to stop the airplane on the runway and the minimum speed at which the takeoff can be continued following the recognition of an engine failure and achieve the required height above the takeoff surface.
V1 (MCG) or VMCG	Minimum Control Speed (ground) The speed which correspond to an engine failure at VMCG plus the speed gained during one second following the engine failure. It is the V1 minimum speed.
V2	Take Off safety speed Also called takeoff screen speed, the minimum speed in the second segment of a climb following an engine failure. V2 is the normal engine inoperative initial climb speed. Minimum V2 must be equal to or greater than 1.13 VS 1g and 1.1 VMCA
V2min	Minimum takeoff safety speed
V3	Steady initial climb speed with all engines operating
V4	Steady climb speed with all engines operating to be achieved by 400 ft gross height
VA	Design maneuvering speed (stalling speed at the maximum legal G-force, and hence the maximum speed at which abrupt, full deflection, control inputs will not cause the aircraft to exceed its G-force limit). Maneuvering speed is limited by aircraft structural characteristics.
VB	Design speed for maximum gust intensity
VBE	Best endurance speed The speed that gives the greatest airborne time for fuel consumed. This may be used when there is reason to remain aloft for an extended period, such as waiting for a forecast improvement in weather on the ground.
VBG	Best power-off glide speed The speed that provides maximum lift-to-drag ratio and thus the greatest gliding distance available.
Vc	Design cruising speed
Vclmax	Max coefficient of lift speed
VD	Design diving speed Usually 1.4×VNO.
VDF/MDF	Demonstrated flight diving speed
Vdmin	Minimum drag
Vef	The Callibrated Airspeed at which the critical engine is assumed to fail
VEF	Velocity Engine Failure The speed at which the critical engine is assumed to fail during takeoff.
VF	Design flap speed
VFC/MFC	Maximum speed for stability characteristics
VFE	Maximum flap extended speed Different maximum speeds may be specified for partial flap extension. Top of white arc on many airspeed indicator.
VFEN	Next Flap Extension Speed or Predictive Vfe At Next Flap/Slat Position
VFTO	Final takeoff speed
VH	Maximum speed in level flight with maximum continuous power.
Vimd or Vmd	Minimum drag
Vimp	Minimum power
VLE	Maximum landing gear extended speed The maximum speed at which the aircraft may be flown with the landing gear extended VLE is always higher than VLO
VLO	Maximum landing gear operating speed The maximum speed at which the aircraft may be flying while raising or lowering the gear. VLO is always lower than VLE
VLOF	Lift-off speed
VLS	Lowest Selectable Speed
VM or VMAN	Recommanded Maneuvering Speed
VMAX	Maximum Operating Speed
VMBE	Maximum Brake Energy speed The maximum speed at which the wheel brakes have demonstrated the abilty to absorb the energy required to stop the airplane for the takeoff conditions.
VMC	Minimum control speed with the critical engine inoperative
VMCA	Minimum Control Speed (Air)
VMCG or V1 (MCG)	see V1 (MCG) or VMCG
Vmcl	Minimum control speed, approach and landing
VMD	Minimum Drag
Vme	Maximum endurance
VMIN	Minimum Operating Speed
VMO/MMO	maximum operating limit speed.
Vmp	Minimum power
Vmr	Maximum range
VMU	Minimum unstick speed.
Vnd	Maximum structural cruising speed
VNE	Never-exceed speed Red line and top of yellow arc on many airspeed indicator.
VNO	Maximum structural cruising speed The maximum speed to be used in turbulent conditions or can refer to the velocity of normal operation. This speed is specific to the aircraft model. VNO is specified as the upper limit of the green arc and bottom of yellow arc on many airspeed indicators. The range above VNO is marked on the airspeed indicator as a yellow arc from VNO to the VNE. The yellow arc is a caution, as speeds in this region may add dangerous stress to the aircraft, and are only to be used in smooth air when no turbulence or abrupt control inputs are expected.
Vp	Aquaplaning speed
VR	Rotation speed The speed of an aircraft at which the pilot initiates rotation to obtain the scheduled takeoff performance. It must be greater or equal to the V1 speed. VR >= 1.05 VMCA
Vra	Rough air speed
VREF	Reference landing approach speed Speed (in calm air) at the landing screen height of 50 ft. Often used by pilots as a base from which to calculate speeds to be used during landing, and calculated as a margin over the stall speed. U usually 1.3×VS0.
VS	Stall speed The stalling speed or the minimum steady flight speed at which the airplane is controllable. Usually synonymous with VS1, stall speed in a specified configuration. Bottom of green arc on many airspeed indicator.
VS0	The stalling speed or the minimum steady flight speed in the landing configuration. Bottom of white arc on many airspeed indicator.
VS1	The stalling speed or the minimum steady flight speed obtained in a specific configuration (usually a configuration "clean" of flaps, landing gear and other sources of drag).
Vs1g	One g stall speed
VSR	Reference stall speed
VSR0	Reference stall speed in the landing configuration
VSR1	Reference stall speed in a specific configuration
VSS	Stick Shaker speed
Vsse	Safe single engine speed
VSW	Speed at which onset of natural or artificial stall warning occurs
Vt	Threshold speed
Vtmax	Max threshold speed
VX	Speed for best angle of climb This provides the best altitude gain per unit of horizontal distance, and is usually used for clearing obstacles during takeoff.
VXSE or VXE	Speed for best angle climb with the critical engine inoperative on multi engine aircraft
VY	Speed for best rate of climb This provides the best altitude gain per unit of time.
VYSE or VYE	Speed for best rate of climb with the critical engine inoperative on multi engine aircraft