Absolute Ceiling

What Is an Absolute Ceiling?

The absolute ceiling is the highest altitude at which an aircraft can achieve and sustain level flight, or the highest altitude at which the aircraft can fly without decreasing airspeed or changing altitude. At an aircraft’s absolute ceiling, the engines are operating at their maximum thrust but, due to the thinner air at higher altitudes requiring higher speed to generate enough lift, will only generate lift equal to the weight of the aircraft. At this altitude, the aircraft cannot accelerate without generating excess lift. The absolute ceiling is usually much higher than is standard operating procedure for aircraft, for both technical and economical reasons.