What happened
On 28 June 2022, a Pawan Hans Limited Sikorsky S-76D helicopter, registration VT-PWI, was conducting a crew change flight to the Sagar Kiran oil rig located off the coast of Mumbai. The flight departed Juhu Aerodrome at 0538 UTC with seven passengers and a two-person crew.
During the final approach to the rig, the aircraft entered an uncontrolled flight state. The helicopter performed an aggressive, unintended nose-up maneuver, which was met with a full lowering of the collective by the pilot flying. This sequence triggered a steep, near-zero speed autorotative descent, causing the aircraft to impact the sea.
The investigation
AAIB India investigators analyzed flight data from the Digital Flight Data Recorder (DFDR) and the Cockpit Voice Recorder (CVCO). The inquiry examined the crew's handling of the Automatic Flight Control System (AFCS) and the operational environment at the Sagar Kiran rig.
Investigators also reviewed safety equipment and emergency procedures. It was discovered that the passenger safety briefing video contained errors, specifically misidentating the Emergency Re-Breathing System (ERBS) toggle as the life jacket inflation mechanism. Furthermore, the investigation looked into the serviceability of rescue equipment on the rig and the adequacy of the passenger safety briefing cards provided by the operator.