The helicopter was on a routine sortie, when the mishap took palce.
According to the sources, the air crash took place at 8:45 am, about five km from Vishwema helipad, on the borders of the two North Eastern states.
While two bodies of the crash victims were recovered, the third person was yet to be traced, a Defence Spokesperson in Kolkata said.
The spokesperson, however, withheld the identity of the three persons, including two pilots, who were on board.
The crash took place due to bad weather, the spokesperson said.
A search operation was on to locate the third person and a court of inquiry is also ordered.