A military chopper had crashed in Tamil Nadu. CDS Bipin Rawat, his wife and other officers were in the chopper

New Delhi: Sudden cloud cover, which led to Controlled Flight Into Terrain (CFIT), has been identified as the reason behind the helicopter crash last month which claimed the lives of 14 people, including India’s first Chief of Defence Staff (CDS) Gen. Bipin Rawat.

Air Chief Marshal V.R. Chaudhari, head of the Indian Air Force, along with Air Marshal Manvendra Singh, Air Officer Commanding-in-Chief of the Training Command, who headed the tri-service inquiry into the crash that took place in the forest near Coonoor in Tamil Nadu, briefed Defence Minister Rajnath Singh on the probe Wednesday.

Defence sources said that the probe has ruled out any technical malfunction, sabotage or any kind of missile attack as reasons for the crash.

The probe looked into multiple aspects of the crash, including examining the helicopter structure, Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR), both of which together are known as the ‘black box’ of an aircraft.

Sources said data from the FDR and the CVR revealed that there was nothing to indicate any kind of disorientation of the pilots — Wing Commander Prithvi Singh Chauhan and Squadron Leader Kuldeep Singh.

“This was a CFIT due to sudden cloud cover which had moved in,” a source said.

The US’ Federal Aviation Administration Safety defines CFIT “as an unintentional collision with terrain (the ground, a mountain, a body of water, or an obstacle) while an aircraft is under positive control”.

It adds that most often, the pilot or crew is unaware of the looming disaster until it is too late, and it most commonly occurs in the approach or landing phase of a flight.