An Auxiliary Power Unit, commonly referred to as APU, is a small turbine engine usually located in the tail section of an aircraft. Unlike the main engines that provide thrust for flight, the APU is designed to provide energy for functions other than propulsion.

The auxiliary power unit (APU) of an Air India Airbus A321 (TV-TVG), located in the tail section, caught fire at Delhi's Indira Gandhi Inte.

An Air India plane's auxiliary power unit caught fire after landing at the Delhi airport on Tuesday afternoon, and all passengers and crew members are safe.