Definition 1 of 2
Definition
The greatest total weight at which an aircraft is certificated and approved to begin its takeoff roll, including the airframe, engines, fuel, oil, crew, passengers, baggage, and cargo. This limit is established by the manufacturer and published in the aircraft's Type Certificate Data Sheet and Pilot's Operating Handbook, and exceeding it is prohibited by regulation.
Plain English
The heaviest the aircraft is allowed to be when it starts its takeoff. Add up everything on board -- fuel, people, bags, the aircraft itself -- and the total cannot be more than this number.
Context Anchor
Seen during preflight planning, weight-and-balance checks, aircraft limitations, and performance planning before departure.
Derivation
Gross' here means the total weight of everything together, not just the aircraft itself -- the same sense as 'gross income' before deductions. So 'maximum gross takeoff weight' means the highest allowable total weight at the moment of takeoff.
Why Pilots Care
Exceeding this limit reduces climb performance, increases takeoff distance, and can cause structural or control problems.
Intuition Check
“Gross” does not mean unpleasant here; it means total. “Maximum” does not mean a suggested loading goal; it means the upper limit you must not exceed for takeoff.
Example Sentence 1
After loading the bags and topping off the fuel, the pilot recalculated the totals and confirmed the aircraft was 80 pounds under its maximum gross takeoff weight.
Example Sentence 2
High density altitude forced the pilot to reduce fuel load so the airplane would not exceed maximum gross takeoff weight.