Acceleration Altitude

Acceleration Altitude is the height above ground level at which the pilot reduces pitch angle and begins accelerating from V2 to the en-route climb speed after takeoff.

It is specified in the Standard Instrument Departure (SID) or operator procedures, typically between 800 ft and 1,500 ft AGL. Below acceleration altitude, the priority is obstacle clearance; above it, the aircraft 'cleans up' (retracts flaps/slats) and accelerates.

• Set during departure briefing based on obstacle analysis
• Lower altitudes are used at airports with no significant terrain
• Noise-sensitive airports may have specific acceleration altitude requirements