Aviation runs on a small alphabet of speeds, each written with a capital V and a subscript. They look cryptic, but every one answers a practical question: how slow is too slow, how fast is too fast, when do I lift off, when can I no longer stop. Learn what the V means and which speeds are limits, and the airspeed indicator turns from a dial into a set of instructions.
This is general educational information, not operational, legal, or regulatory advice. Rules differ by authority and change over time. Always verify against current official sources and follow your operator's approved procedures.
What a V-speed is
The V comes from the French vitesse, speed. Each V-speed is a defined speed with a single agreed meaning, and the abbreviations are standardised in regulation, for example 14 CFR 1.2 in the United States and the equivalent EASA certification specifications, so that the same symbol means the same thing on every aircraft. The values, though, are particular to each type and are published in its flight manual, because a stall speed or a never-exceed speed that is right for one aircraft is wrong for another.
A useful split is between limits, speeds you must not exceed, and operating speeds, targets you aim for. Vne is a limit; Vy, the best rate of climb, is an operating speed.
The airspeed indicator's colour code
The fastest way to learn the core speeds is the colour code on a light-aircraft airspeed indicator, set out in the FAA Pilot's Handbook:
- the white arc is the flap operating range, from Vs0 (the stall speed in the landing configuration) up to Vfe (the maximum flap-extended speed);
- the green arc is the normal operating range, from Vs1 (the clean stall speed) up to Vno (the maximum structural cruising speed);
- the yellow arc is a caution range, from Vno up to Vne, to be used only in smooth air;
- the red line marks Vne, the never-exceed speed.
The takeoff and landing speeds
For larger aircraft the FAA Airplane Flying Handbook and SKYbrary add the speeds that frame a takeoff and landing:
- V1, the takeoff decision speed: at or above it there is no longer room to stop on the runway, so the takeoff is continued even with an engine failure;
- Vr, the rotation speed, where the nose is raised to lift off;
- V2, the takeoff safety speed, the minimum speed to climb away safely with an engine failed;
- Vref, the reference landing speed, the target speed crossing the threshold, traditionally about 1.3 times the landing-configuration stall speed.
And the speed many pilots misremember: Va, the design manoeuvring speed, below which full deflection of a single control will not overstress the airframe. Crucially, Va is lower when the aircraft is lighter.
A worked example
Reading a light aircraft's airspeed indicator on a normal circuit: on downwind you are in the green arc, comfortably above the clean stall (the bottom of the green) and below Vno (the top of it). Turning final you select flap and slow into the white arc, staying below Vfe at the top of it so the flaps are not overspeeded, and above Vs0 at the bottom so you do not stall in the landing configuration. You would only enter the yellow arc in smooth air, knowing that the red line, Vne, must never be passed.
The Va point is the one to reason through. If your aircraft's Va is 99 knots at maximum weight, then flown light, with two people instead of four and less fuel, the speed at which an abrupt full control input would overstress the airframe is lower, not higher. A lighter aircraft reaches its limiting load factor sooner, so in turbulence when light, you slow down more, not less.
Common pitfalls
- Know which speeds are limits. Vne, Vfe, Vno and Vlo are limits with consequences; treat them as walls, not suggestions.
- Va falls with weight. The lighter you are, the lower the manoeuvring speed, the opposite of most people's intuition.
- The numbers are yours, not generic. Every figure here is a definition; the actual speeds come from your aircraft's flight manual, so fly those.
In Pilot EFB
Pilot EFB is a study and planning companion for exactly the kind of speed knowledge a checkride and a safe flight demand, and it sits alongside your weather, NOTAMs, flight time and logbook in one offline-first place. It does not hold your aircraft's certified V-speeds or replace the flight manual, so work your numbers from the manual and treat the app as a study aid. Pilot EFB is not a certified Electronic Flight Bag, so treat it as a study and planning aid and brief from your official source of record.