NEW DELHI:  Five military personnel were killed and one critically wounded when an Indian Air Force helicopter crashed at Tawang in Arunachal Pradesh this morning, reported NDTV.

The Mi-17 V5 chopper was on an "air maintenance mission" when it crashed around 6 am, according to the Air Force.

A Court of Inquiry has been ordered to establish what caused the crash.

The Mi-17 V5 chopper is the backbone of the Air Force; 48 more have been requisitioned.

Over 100 such helicopters are in service.

The Mi-17 can carry a substantial payload to higher altitudes and has a very powerful engine.