The investigation team set up to probe the helicopter crash which killed first Chief of Defence Staff (CDS) General Bipin Rawat, his wife and 12 others briefed Defence Minister Rajnath Singh here on Wednesday.
Bad weather reportedly was the cause for the accident killing all onboard. Technically, it is known as Controlled Flight into Terrain (CIFT) wherein an aircraft unintentionally collides with terrain be it ground, mountain or a tree-top.
The tri-service Court of Inquiry headed by Air Marshal Manvendra Singh, himself an accomplished helicopter pilot and currently Chief of Training Command, and IAF chief VR Chaudhari, apprised Rajnath here about the findings of the investigations.
While there was no official word about the report, sources said the MI-17 helicopter was trapped in a cloud due to weather suddenly turning bad moments before it was to land. The helicopter crashed into a cliff, they said.
The accident took place on December 8, 2021, when General Rawat, his wife Madhulika, his defence adviser Brigadier LS Lidder, staff officer to the Chief of Defence Staff, Lt Colonel Harjinder Singh and decorated pilot Group Captain Varun Singh and others were to land at the Defence Services Staff College (DSSC), Wellington. General Rawat was scheduled to give a lecture there later in the day. The helicopter crew members too were killed in the crash.
The Court of Inquiry investigated all the aspects, including the possibility of malfunction in the helicopter mechanism, any technical or human error leading to the accident. The investigators also examined the black box or flight data recorder and cockpit voice recorder, they added.
The probe team examined all likely scenarios for the crash, including possible human error or whether it was a case of disorientation of crew when the helicopter
was preparing for landing, sources said.
The helicopter crew had not made any distress call to the ground station when it suddenly encountered thick clouds indicating that the pilots were in control of the helicopter. The commander of the flight was Wing Commander Prithvi Singh Chauhan and Squadron Leader Kuldeep Singh was the co-pilot. Both of them were highly skilled pilots with Master Green rating, they said.
The CIFT phenomenon says 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.
Moreover, the CFIT occurs when an airworthy aircraft, while under the complete control of the pilot, is inadvertently flown into terrain, water, or an obstacle.
According to the IATA (International Air Transport Association), the term refers to accidents in which in-flight collisions with terrain, water, or another obstacle occur without indication of loss of control.
The United States Federal Aviation Administration says CFIT is ‘’ ... an unintentional collision with terrain (ground, mountain, body of water, or an obstacle) while an aircraft is under positive control.” The critical distinction in such incidents is the fact the aircraft is under control of the flight crew.