Two mechanics were killed by rotor blades on Thursday when the helicopter they were servicing tilted on its side, an transport ministry official said.
The pilot and mechanics were making last-minute checks on the aircraft before take-off when the accident happened at a military airport about 30 kilometres southwest of the Indonesian capital Jakarta, said transport ministry spokesman Bambang Ervan.
The spinning blades killed the two mechanics instantly while the pilot and another technician in the cockpit were injured, he said
Police said the helicopter belonged to the Pelita Air Service charter company, reported dpa.