# Maneuvering speed

A flight envelope diagram showing VS (Stall speed at 1G), VC (Corner/Maneuvering speed) and VD (Dive speed)

In aviation, the maneuvering speed of an aircraft is an airspeed limitation selected by the designer of the aircraft. At speeds close to, and faster than, the maneuvering speed, full deflection of any flight control surface should not be attempted because of the risk of damage to the aircraft structure.[1]

It has been widely misunderstood that flight below maneuvering speed will provide total protection from structural failure, such as in American Airlines Flight 587. Due to this accident a CFR Final Rule was issued effective October 15, 2010 clarifying this misconception.[2]

The maneuvering speed of an aircraft is shown on a cockpit placard and in the aircraft's flight manual but is not commonly shown on the aircraft's airspeed indicator.

In the context of air combat manoeuvring (ACM), the maneuvering speed is also known as corner speed or cornering speed.[3]

## Design maneuvering speed VA

VA is the design maneuvering speed and is a calibrated airspeed. Maneuvering speed cannot be slower than $V_s \sqrt{n}$ and need not be greater than Vc.[4]

## Maximum operating maneuvering speed VO

Some aircraft have a maximum operating maneuvering speed VO. The concept of maximum operating maneuvering speed was introduced to the USA type-certification standards for light aircraft in 1993.[1][5] The maximum operating maneuvering speed is selected by the aircraft designer and cannot be faster than $V_s \sqrt{n}$, where Vs is the stalling speed of the aircraft, and n is the maximal allowed positive load factor.

At airspeeds slower than $V_s \sqrt{n}$ the aircraft will stall before the structure is subjected to its limiting aerodynamic load. The maneuvering speed or maximum operating maneuvering speed depicted on a cockpit placard is calculated for the maximum weight of the aircraft. Some Pilot's Operating Handbooks also present safe speeds for weights less than the maximum.

The formula used to calculate a safe speed for a lower weight is $\scriptstyle V_A \sqrt{W_2 \over W_1}$, where VA is maneuvering speed (at maximum weight), W2 is actual weight, W1 is maximum weight.[6]