Sources said that the crash occurred after the crew reported a sudden loss of control second before the chopper hurtled to the ground. It is learnt that flight data being studied did not show any obvious reason for the loss of control and the probe team is now examining the transmission system for a possible failure.
Earlier, the indigenous helicopter had undergone comprehensive design review by Netherlands based NLR and had been given a green signal. Recently some changes were made in the transmission system and control rods were changed after instances of material failure came to light.
Sources pointed out that the accident rate of the ALH is 6.5 incidents per lakh hours of flying, saying that for helicopters of this class, the global average is 7.5 incidents per lakh hours. The ALH fleet has flown over 4.5 lakh hours by now and serves in areas ranging from the high seas to high altitude mountain bases.
They added that from 2004 to 2024, there have been nine major accidents involving the fleet, three of which were attributed to human error and three to a technical fault. The reason behind the remaining could not be conclusively determined.
While the air force has the best safety record with the fleet, the coast guard has had the most number of incidents, including a ditching at sea late last year during a complicated Night time rescue attempt. A call on resuming flight operations will be taken jointly by the services and manufacturer HAL.