The incident at Jakarta airport renewed concerns about the safety of flying in Indonesia following two major air accidents this year.
The Boeing 737-400 operated by Batavia Air landed safely and none of 138 passengers and six crew members were hurt, said Anton Situmeang, a spokesman for the airline.
Mr Situmeang said the plane, which was due to fly to Pontianak on Borneo island, could have continued its journey safely without the part, which measured 40cm by 50cm.
"But the pilot decided to return to the airport. It was a standard procedure," he said.
Frans Wenas, senior investigator at Indonesia's National Transport Safety Committee, said the broken piece landed near the airport.
Batavia Air is one of several budget carriers to emerge in Indonesia following the liberalisation of the air industry in the late 1990s.
But the country has suffered a string of deadly accidents in recent years, raising questions about aviation safety.
A plane operated by national carrier Garuda crashed while landing at Yogyakarta airport in March, killing 21 people, including five Australians.
In January, 102 people aboard an Adam Air jet were killed when it plunged into the sea off Sulawesi.
