twin-engine aircraft; twin-engine plane
Refers to any aircraft powered by two engines. Common in aviation contexts.
This twin-engine aircraft is suitable for long-distance flights.
多発機 is a broader term for multi-engine aircraft, while 双発機 specifically means two engines.
Compound of 双 (そう, 'pair') + 発 (はつ, 'engine start' or 'departure') + 機 (き, 'machine/aircraft'). The term is transparently derived from its kanji components.