What happened
Following a routine departure from Trivandrum Airport, the flight proceeded without incident for approximately 35 minutes. Upon receiving clearance from Madras, the aircraft began its descent from a cruising altitude of 27,000 feet. During this phase of flight, a loud explosion occurred in the area of the forward lavatory.
The blast caused immediate and severe consequences for the aircraft's systems, including the loss of cabin lighting and a total failure of electrical and instrument functions. The crew attempted an approach with the landing gear extended but without the use of flaps. The aircraft touched down 2,500 feet beyond the threshold of runway 25 at Madras Airport.
Due to the high speed of the landing and the loss of critical deceleration systems, the aircraft overshot the runway, traveling through a grassy field and across a nullah. After coming to a stop, passengers were evacuated via the front and rear exits. A fire ignited on the starboard side after the aircraft halted, causing significant damage to the starboard wing and resulting in the total destruction of the airframe.
Findings
Investigations determined that the primary event was the detonation of an explosive device located within the forward lavatory. This explosion led to a cascade of system failures, specifically disabling the anti-skid system and reverse thrust capabilities. The combination of these failures and the high touchdown speed prevented the aircraft from stopping within the runway limits, leading to the subsequent overrun and fire. There were 14 injuries reported among the occupants.