A search was underway on Saturday for the missing Army personnel who was on board the chopper that crashed in Upper Siang district of Arunachal Pradesh, a defence spokesperson said.
The advanced light helicopter (ALH), carrying five Army personnel including two pilots, was on regular sorties when it crashed at 10.43 am on Friday near Migging, around 25 km south of Tuting.
The Army and the Air Force were searching to locate the mortal remains of the fifth personnel, defence spokesperson Lt Col A S Walia said.
The crash site is extremely challenging in terms of hills with steep gradients and thick jungle, he said.
"The bodies of four Army personnel were recovered on Friday evening from the crash site in a densely wooded mountainous area, around 35 km from the border with China," he said.
The cause of the crash is not yet known and details are being ascertained, the officer said.
"It is reported that the weather was good for flying operations. The pilots had more than 600 combined flying hours on ALH-WSI and over 1,800 service flying hours between them. The aircraft was inducted into service in June 2015," he said.
"Prior to the crash, the Air Traffic Control (ATC) had received a 'May Day' call suggesting a technical or mechanical failure," he said.
"This will form the focus of the Court of Inquiry, which has been immediately constituted to investigate the causes of the accident. Names of the personnel will be released after notification to the next of kin," Lt Col Walia said.
The Army helicopter, also known as HAL Rudra, had taken off from Likabali in Lower Siang district.
The HAL Rudra is an attack helicopter manufactured by Hindustan Aeronautics Limited (HAL) for the Indian Army. It is a weapon system integrated (WSI) Mk-IV variant of the Dhruv advanced light helicopter (ALH) and is the first armed helicopter produced indigenously in India.
This is the second accident involving an Army helicopter in Arunachal Pradesh this month.
A Cheetah helicopter crashed in Tawang district on October 5 and claimed the life of one of its two pilots.
According to records, Arunachal Pradesh has witnessed 13 crashes since 1995, and 47 people were killed in them.
