The number of engines of civil airliners is mainly determined by their design age, passenger capacity and travel requirements. The following are the representative models of different engines and their specific models:
· Shuangfa (2 units): At present, civil aviation is the mainstream with high fuel efficiency. Representative models include Boeing 737 series (installed with CFM56 series), Airbus A320 series (installed with CFM56-5 or V2500), and long-range wide-body passenger aircraft such as Boeing 787 and Airbus A350.
· Sanfa (3 units): It was mainly popular in the late last century and has now been discontinued. The representative models are the McDow DC-10 and the Soviet Union's Tu-154.
· Four shots (4 units): mainly used for long-distance international routes and large passenger aircraft in the past. Representative models include the "Queen of the Air" Boeing 747 series (such as the 747-400 equipped with PW4062, etc.) and the "Air Giant" Airbus A380.
· Special configuration (5/6 units): extremely rare. The representative of the six engines is the ultra-large transport aircraft An-225; the five are usually temporary transportation, such as the Boeing 747 of the airline, which is mounted under the wings of the spare engine for transfer.
In general, double hair is the most mainstream design at present. Four hair is gradually withdrawing from the passenger stage, while three hair has become history.
