Twinjet

A twinjet or twin jet is a jet aircraft powered by two engines. Such configuration of an aircraft is the most popular today for commercial airliners, for fighters, and many other kinds, because while offering safety from a single engine failure, it is also acceptably fuel-efficient.

Aircraft configurations

As of today, there are three most common configurations of this kind of an airplane. The first has a podded engine mounted beneath, or occasionally above or within, each wing (standard narrow-body and wide-body airliners). The second has one engine mounted on each side of the rear fuselage, close to its empennage (most business jets). In the third configuration, both jet engines are within the fuselage, side-by-side. The third configuration is notable for being used on most fighters since the 1960s, and still continuing, for example in the Su-27 'Flanker', the F-15 Eagle, and the F-22 Raptor.

The first "twinjet" ever to fly was the April 1941-debuted German fighter prototype Heinkel He 280, flying with a pair of nacelled Heinkel HeS 8 axial-flow turbojets.