The crash occurred due to “unexpected change” in weather conditions that led to spatial disorientation of the pilot, the IAF said.
The tri-services inquiry into the Mi-17 V5 helicopter that killed Chief of Defence Staff (CDS) Gen. Bipin Rawat and 13 others has submitted its preliminary findings according to which the crash occurred due to “unexpected change” in weather conditions that led to spatial disorientation of the pilot resulting in Controlled Flight into Terrain (CFIT), the Indian Air Force (IAF) said on January 14.
“The Court of Inquiry (CoI) 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. This led to spatial disorientation of the pilot resulting in CFIT,” the IAF said in a statement. “Based on its findings, the CoI has made certain recommendations which are being reviewed.”
The IAF added that 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.
As reported by The Hindu on January 1, the inquiry findings which were sent for legal vetting before being submitted to the Defence Ministry had indicated CFIT as the probable cause of the crash.
The IAF Mi-17V5 helicopter with Gen. Rawat, his wife Madhulika Rawat and 12 others including his staff, the pilots and crew was enroute to the Defence Services Staff College, Wellington from Sulur on December 8 when it crashed in the Nilgris in Tamil Nadu close to the destination. A tri-services inquiry was ordered by the IAF headed by Air Marshal Manvendra Singh, Air Officer Commanding-in-Chief Training Command to investigate the crash.
The U.S. Federal Aviation Administration, 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. “Most often, the pilot or crew is unaware of the looming disaster until it is too late. CFIT most commonly occurs in the approach or landing phase of flight,” an FAA fact sheet states.