Definition
The reduction in aircraft weight that occurs as fuel is consumed during flight. In weight and balance calculations, fuel burnoff must be accounted for because it changes both the total weight of the aircraft and the location of the center of gravity, since fuel is stored in tanks that sit at specific arms from the reference datum.
Plain English
The weight an airplane loses as it uses up fuel during flight. As fuel burns off, the aircraft gets lighter, and its balance point can shift depending on where the fuel tanks are located.
Context Anchor
Seen in weight-and-balance calculations when checking whether the aircraft will remain within limits at takeoff, during flight, and at landing after fuel has been used.
Why Pilots Care
Failing to account for fuel burnoff can cause the aircraft to exceed center of gravity limits later in flight even if it was legal at takeoff.
Grounding Statement
Picture fuel as weight sitting in the tanks; as the flight continues, that weight is gradually removed from that part of the aircraft.
Intuition Check
Fuel burnoff does not mean fuel is dumped or wasted. It means fuel has been consumed by the engine, and its lost weight must be accounted for in the aircraft’s balance.
Example Sentence 1
After calculating fuel burnoff for the two-hour flight, the pilot confirmed the aircraft would still be within center of gravity limits on landing.
Example Sentence 2
Wing tank fuel burnoff caused a slight aft shift in the center of gravity as the flight progressed.