Pilot disorientation due to weather change led to CDS chopper crash: Court of Inquiry

An unexpected change in weather that disoriented the pilot who then probably hit the aircraft at a surface had led to the December 8, 2021, crash of the Mi-17 V5 with India’s first chief of defence staff, General Bipin Rawat, the tri-services’ Court of Inquiry has found.

Air Force Chief Air Chief Marshal V K Chaudhari, along with the head of the probe committee, Air Marshal Manvendra Singh had briefed Defence Minister Rajnath Singh about the findings on January 5.

The Indian Air Force said on Friday that the Court of Inquiry had submitted its preliminary findings ruling out mechanical failure, sabotage and negligence. “The Court of Inquiry has ruled out mechanical failure, sabotage or negligence as a cause of the accident. The accident was a result of entry into clouds due to unexpected change in weather conditions in the valley,” the IAF said, adding “spatial disorientation of the pilot resulting in controlled flight into terrain or CFIT” was the cause of the crash as per the inquiry report.

Considered one of the primary causes of aircraft crashes globally, CFIT is when an aircraft is considered airworthy—with no negligence on the part of the pilot—hits a surface unintentionally due to the disorientation the pilot.

The air force said the Court of Inquiry had made certain recommendations, “which are being reviewed”.

The tri-services inquiry including one-star officers from the Navy and the Army and headed by Manvendra Singh, who is the senior-most helicopter pilot in the IAF, was instituted soon after the crash. “The inquiry team analysed the Flight Data Recorder and Cockpit Voice Recorder besides questioning all available witnesses to determine the most probable cause of the accident,” said the IAF.

The helicopter was descending to land when it ran into sudden clouds, which resulted in the pilot’s disorientation.

The Mi-17 V5 was carrying Rawat, his wife, Madhulika Rawat, along with 12 other personnel of the armed forces, including Rawat’s senior staff members Brig LS Lidder and Lt Col Harjinder Singh, and IAF officers Wing Commander Prithvi Singh Chauhan, Squadron Leader Kuldeep Singh. While 13 of the 14 passengers died in the crash, Group Captain Varun Singh, who survived it, succumbed to his injuries a week later.

On December 9, Defence Minister Rajnath Singh informed Parliament that the helicopter had taken off from the Sulur airbase at 11.48 am and was expected to land at Wellington by 12.15 pm. The Air Traffic Control at the Sulur airbase lost contact with the helicopter at approximately 12.08 pm.

Local residents had spotted a fire in the forest near Coonoor, Tamil Nadu, and rushed to the spot where they observed the wreckage of the helicopter engulfed in flames, Singh had said. Rawat was on his way to deliver a lecture at the Defence Services Staff College, Wellington in the Nilgiris district. The government is yet to appoint his replacement.