Speed Brake

A speed brake (also called a dive brake or spoiler) is a moveable aerodynamic surface that, when extended, creates additional drag and reduces lift, allowing the aircraft to descend at a higher rate or decelerate without significantly changing pitch attitude.

Speed Brakes in Operations

• Descent management: extend to increase rate of descent when ATC issues a “speed increase” or “cross restriction” at altitude
• Speed control on approach: useful for high-and-fast corrective action
• Landing roll: deployed on touchdown on many aircraft to spoil lift and increase weight on wheels for better braking

Speed Brake Limitations

Speed brake deployment must not exceed the aircraft’s maximum speed brake extension speed (V_SB). Do not extend speed brakes simultaneously with flap extension on aircraft where these are prohibited together. Refer to the POH for aircraft-specific limitations.

Related Terms

See also: V_NE, Landing Roll.