Plain English Meaning
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.
Full 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.
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.