Definition
An aircraft powered by two or more engines. In the weight and balance context, multi-engine aircraft are subject to additional loading considerations because engine placement, fuel distribution across multiple tanks, and the position of the center of gravity all affect handling, performance, and controllability — particularly if one engine fails.
Plain English
An airplane with more than one engine. Because it has multiple engines and usually multiple fuel tanks, where the weight sits matters more than in a single-engine airplane.
Context Anchor
Seen in weight and balance, aircraft performance, training, and emergency procedure discussions.
Derivation
“Multi-” comes from the Latin multus, meaning “many.” So “multi-engine” simply means “many engines” — in practice, two or more.
Why Pilots Care
Affects loading limits, performance data, and emergency procedures that single-engine aircraft do not share.
Intuition Check
Do not assume “multi-engine” means the aircraft is automatically safer, faster, or able to climb well on one engine. The term only tells you that the aircraft has two or more engines.
Example Sentence 1
Before flying a multi-engine aircraft as pilot in command, you must hold a multi-engine rating on your pilot certificate.
Example Sentence 2
Multi-engine aircraft require separate performance charts for takeoff with one engine inoperative.