A Chetak helicopter of the Indian Air Force toppled while making an emergency landing during a training sortie from Bamrauli near Allahabad on Wednesday.
Both the pilots are safe.
The chopper toppled when the pilots tried a forced landing after it developed a technical snag, sources in IAF said.
The IAF has ordered a court of inquiry (COI) to ascertain the cause of the accident.
The sources said the aircraft toppled while the pilots tried to force land it on an uneven field.
The helicopter was on a routine training sortie from Bamrauli.