Airplane jet engines. These are turbofan engines, a type of jet engine used in passenger aircraft as they are quieter than other types of jet engine. This is the front of the engines where a fan draws in air to power the engine, which itself powers the fan. The exhaust gases emerging from the back of the engines provide thrust and keep the plane airborne. These are Avco-Lycoming ALF-502 turbofan engines seen on a BAe 146 passenger airplane. The aircraft about to land (upper left) is an Airbus A320. Photographed at Manchester Airport, England.