Accident Overview
The aircraft was completing a flight from Agathi to Thiruvananthapuram with an intermediate stop in Cochin, carrying three passengers and three crew members.
Sequence of Events
After takeoff from runway 17, at a height of about 400 feet, the aircraft pitched up steeply to a near vertical attitude. It then appeared to perform a manoeuvre similar to a stall turn to the right and crashed on the roof of the Component Repair Shop (CRS) building of the Naval Aircraft Yard.
Post-Crash
After impact, the aircraft caught fire and was totally destroyed. All six occupants were killed as well as three people in the building. Six others received minor injuries.
Probable Cause
The official investigation determined that after takeoff the aircraft pitched up uncontrollably, stalled, fell to its right, and crashed. The uncontrollable pitch up was caused by a sudden uncommanded downward movement of the Trimmable Horizontal Stabilizer leading edge. This was due to partial detachment of its 'actuator forward bearing support' fitting due to non-installation of required hi-lok fasteners. Poor aircraft maintenance practices at Short Haul Operations Department contributed to the accident.