V-speeds

”V-speeds” är vanliga termer som används för att definiera flygfarter som är viktiga för drift av luftfartyg. Med luftfartyg menar jag till exempel flygplan, segelflygplan, helikoptrar och luftskepp. Dessa farter härleds från data som erhålls av flygplansdesigners och tillverkare under test- flygningar och kontrolleras i de flesta länder av statliga inspektörer under flygplanets typcertifiering. Användningen av V-speeds ses som ett bra sätt att förbättra flygsäkerheten, prestandan och handhavandet av luftfartyget.

Den faktiska hastigheten given av dessa V-speeds är unika för alla flygplansmodeller och de uttrycks i indikerade farter (farten som avläses på fartmätaren i flygplanet) så att piloter kan använda dem direkt, utan att tillämpa korrektionsfaktorer.

Här kommer en tabell med ett antal V-speeds. Det finns fler men dessa är de viktigaste som man kommer i kontakt med mest!

Vspeed Beskrivning
V1 Maximum speed during takeoff at which a pilot can safely stop the aircraft without leaving the runway. This is also the minimum speed that allows the pilot to safely continue (to V2 takeoff) even if a critical engine failure occurs (between V1 and V2).
V2 Takeoff safety speed.
V2min Minimum takeoff safety speed.
V3 Flap retraction speed.
VA Design maneuvering speed, also known as the ”Speed for maximum control deflection.” This is the speed above which it is unwise to make full application of any single flight control (or ”pull to the stops”) as it may generate a force greater than the aircraft’s structural limitations.
VB Design speed for maximum gust intensity.
VC Design cruising speed, also known as the optimum cruise speed, is the most efficient speed in terms of distance, speed and fuel usage.
VD Design diving speed.
VDF Demonstrated flight diving speed.
VEF The speed at which the critical engine is assumed to fail during takeoff.
VF Designed flap speed.
VFC Maximum speed for stability characteristics.
VFE Maximum flap extended speed.
VFTO Final takeoff speed.
VH Maximum speed in level flight at maximum continuous power.
VLE Maximum landing gear extended speed. This is the maximum speed at which it is safe to fly a retractable gear aircraft with the landing gear extended.
VLO Maximum landing gear operating speed. This is the maximum speed at which it is safe to extend or retract the landing gear on a retractable gear aircraft.
VLOF Lift-off speed.
VMC Minimum control speed with the critical engine inoperative.
Vmcg Minimum control speed on the ground – the minimum airspeed at which the aircraft is directionally controllable during acceleration along the runway with one engine inoperative, takeoff power on the operative engine(s), and with nose wheel steering assumed 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.
VR Rotation speed. The speed at which the airplane’s nosewheel leaves the ground.
VRef Landing reference speed or threshold crossing speed.
VS Stall speed or minimum steady flight speed for which the aircraft is still controllable.
VS0 Stall speed or minimum flight speed in landing configuration.
VS1 Stall speed or minimum steady flight speed for which the aircraft is still controllable in a specific configuration.
VSR Reference stall speed.
VSR0 Reference stall speed in landing configuration.
VSR1 Reference stall speed in a specific configuration.
VSW Speed at which the stall warning will occur.
VTOSS Category A rotorcraft takeoff safety speed.
VX Speed that will allow for best angle of climb.
VY Speed that will allow for the best rate of climb.