Definition
The rate at which an object's velocity increases as it falls freely toward the Earth under the influence of gravity, in the absence of air resistance. The standard value is approximately 32.2 feet per second per second (9.81 meters per second per second) at sea level.
Plain English
How fast a falling object speeds up as gravity pulls it down. Each second it falls, it gains about another 32 feet per second of speed.
Context Anchor
Seen in discussions of g loading, turns, stalls, aircraft structure, and basic flight physics.
Derivation
From Latin gravitas, meaning 'weight' or 'heaviness', and accelerare, 'to hasten'. Together they describe the speeding-up caused by the Earth's pull.
Why Pilots Care
Aircraft weight, takeoff distance, climb performance, and structural loads are all calculated using this fixed value.
Analogy
If you drop a small object, it does not just move downward; it keeps speeding up as it falls. Gravitational acceleration is the rate of that speeding up.
Grounding Statement
Drop a wrench from a hover: after one second it's falling at about 32 ft/sec; after two seconds, about 64 ft/sec. That steady increase is gravitational acceleration.
Intuition Check
Do not read “acceleration” here as the airplane speeding up forward. In this term, it means the downward speeding-up caused by gravity.
Example Sentence 1
Load factor is expressed in multiples of gravitational acceleration, so a 3 G turn means the aircraft and pilot feel three times their normal weight.
Example Sentence 2
During a turn the pilot feels increased load because lift must overcome both gravitational acceleration and the additional centripetal requirement.