Many English-speaking people think that “V” stands for Velocity, which is generally correct. But another French aviation phrase, “Vitesse” – which means “speed” – is represented by the letter “V” in V-Speed. The FAA requires that aircraft manufacturers provide certain V-speeds to ensure the safest and most efficient flow of air traffic. They are standard aviation terms used to identify the critical operational airspeeds for various phases of flight. V-speeds are valuable tools that help pilots responsibly and effectively operate their aircraft.
V-Speed for Takeoff
- V1 = Takeoff Decision Speed: This refers to the maximum speed at which the pilot can stop the aircraft on the runway in case of a canceled takeoff, after acceleration. The bigger the plane, the higher the V1, since the airspeed depends on weight. However, aircraft weight is not the only factor to consider; there is also the weight of the cargo, the configuration of the airplane, runway slope, wind speed, and temperature (including the presence of rain or ice).
- V2 = Takeoff Safety Speed: If one engine fails (in a multi-engine aircraft) during takeoff, V2 is the speed at which this disabled aircraft can still safely climb. V2 will vary depending on the position of the flaps at the time of the engine malfunction.
- VX = Best Angle of Climb: Vx is the maximum altitude gain in the shortest horizontal distance (knowing this metric is the key to calculating this speed). Pilots use VX to avoid obstacles such as tall buildings or cell phone towers.
- VY = Best Rate of Climb: VY is the speed that provides the maximum altitude gain in the least amount of time, used to clear the airspace as quickly as possible.
V-Speed In Flight
- VNE = Never Exceed: This speed is almost always designated by a heavy red line on the aircraft’s speed indicator. Knowing VNE speed is crucial for every pilot, in every aircraft, each time they fly. Exceeding this airspeed will result in probable structural failure.
- VNO = Safe Structural Cruising Speed: VNO is the top limit of the arc represented in green on the airspeed indicator and shows the maximum speed at which you may safely fly in calm air with no turbulence. If the aircraft begins to drift above VNO and approach VNE, the needle will move into the yellow arc, or “caution range.”
- VA = Design Maneuvering Speed: This is the maximum speed for an aircraft in flight during turbulence or heavy wind gusts. The manufacturer usually determines this speed based on the maximum gross weight of the aircraft. However, the VA changes when the plane is being operated at less than max gross. For this reason, it is a critical safety issue to understand how to calculate this speed based on the actual aircraft weight.
V-Speed During Landing
- VFE = Maximum Flap Extended Speed: When flying with the flaps fully or even partially extended, there is a risk of damaging or even destroying one or multiple flaps if you let your speed get over VFE. Maximum Flap Extended Speed is specific to each flap setting. On an airspeed indicator, VFE is sometimes marked at the top of the white arc.
- VS / VS0 = Stall Speed (Minimum Speed) in Clean/Dirty Landing Configuration: Pilots extend the flaps of the airplane to create an increase in drag, which slows the aircraft in preparation for landing. But how will the pilot know how slowly the aircraft may go before it stalls? VS is the stall speed of the aircraft in clean configuration – while the landing gear and flaps are still up. VS0 is the stall speed of the aircraft in landing configuration, meaning the landing gear and flaps are down (sometimes referred to as dirty configuration).
Where Are These V-Speeds Displayed?
It is an airworthiness regulatory requirement to represent these V-Speeds in the best possible way in the cockpit. Direct display of essential V-Speeds on the flight instrument dial is done to meet this regulatory requirement. On the front of an aircraft’s airspeed indicator, color-coded arcs and lines represent the most regularly utilized and safety-critical airspeeds. Wing flaps are extended at the lower end of the white arc and retracted at the lower end of the green arc, respectively. These are the airplane’s maximum weight stall speeds. When flying in calm air, the airplane may be handled inside the yellow band but only with extreme care to prevent sudden control movements, and the red line represents the VNE, or maximum permitted speed.
There are many other V-speed terms used in aviation. The pilot shorthand list above contains just a few of the most frequently used terminology. If you are interested in learning more about flying, being a pilot, or anything else related to aviation, please contact California Aeronautical University for further information.
Mr. Matthew A. Johnston has over 23 years of experience serving various roles in education and is currently serving as the President of California Aeronautical University. He maintains memberships and is a supporting participant with several aviation promoting and advocacy associations including University Aviation Association (UAA), Regional Airline Association (RAA), AOPA, NBAA, and EAA with the Young Eagles program. He is proud of his collaboration with airlines, aviation businesses and individual aviation professionals who are working with him to develop California Aeronautical University as a leader in educating aviation professionals.