What are V-Speeds?

V-speeds are a set of aircraft speeds that serve as a guide for aircraft operators. They indicate the speeds an aircraft must reach or maintain during several stages of flight for ideal performance and safety. Most aircraft such as, fixed wing planes, helicopters and gliders have their own V-speed standard. Commercial and private pilots are generally required to have a working knowledge of a particular aircraft’s V-speeds before they are given a license to fly that aircraft.

The V in V-speed stands for velocity, and the majority of V-speed charts use knots to indicate aircraft speed. In the case of old aircraft, airspeed is shown using kilometers or miles per hour. For aircraft capable of reaching high speeds, mach numbers are typically used instead.

Aircraft manufacturers and a country’s aviation regulation department are the organizations that normally regulate V-speeds. The individual airspeeds that comprise the whole V-speed set are mostly determined through a series of criteria that measures various aspects of an aircraft’s design and performance.

Several factors are taken into account when setting the V-speeds. The aircraft’s design, the material it is built from, and its maximum and minimum weight are among the most important aspects of airspeed calculation. After the speeds are defined, the manufacturer subjects the aircraft into rigorous testing to determine whether it is operational at the predetermined speed.

A majority of aircraft instruments have a way of helping the pilot monitor how fast the plane is going relative to its V-speed without requiring the pilot to memorize specific speeds. A typical airplane speedometer employs a color coded gauge that signifies when the plane is traveling above, below, or at just the right V-speed for the current flight stage. This is advantageous, as the number of functions performed when flying an aircraft can make it difficult to recall information.

One of the most vital functions of the V-speeds is to inform the pilot of critical speeds under different scenarios. The pilot can usually tell a V-speed’s purpose according to its subscript. For example, V₁ is the speed at which the aircraft is still capable of taking off in the engine fails. This is also the speed, at which the aircraft can brake and not overshoot the runway.

In addition, any V speed subscript that starts with an s like a V_so and a V_sr pertains to the speed in which the plane is at highest risk of stalling. Meanwhile, V_r is the highest speed at which the aircraft can turn. V_ne is the never speed that should never be exceeded, implying that going above this speed would result in structural damage to the aircraft.