Airplane engines are the power sources that propel aircrafts through the air. Fanjets, also known as turbofan engines, are a type of jet engine that is used in most modern commercial aircrafts. They are characterized by a fan-like structure that helps to reduce fuel consumption and noise levels. MOPEDS, or Multi-Stage Opposed Piston Engines, are a type of reciprocating engine that is used in some smaller aircrafts. They are characterized by their lightweight design and low fuel consumption.