What happened
On March 9, 1998, at 13:45, an Eurocopter AS 350 helicopter, registered F-GHUM, was preparing for a photography mission from the helideck of a vessel located in Pompierre Bay, Terre de Haut, Les Saintes. The aircraft was positioned on the boat's deck with its rotors turning and the right-side doors removed.
As the pilot applied power to initiate takeoff, the aircraft was still secured to the deck by two forward tie-down ropes that had not been released. This restriction caused the helicopter to pitch forward and then backward before overturning and falling into the sea onto its back. The aircraft subsequently sank to a depth of approximately 35 to 40 meters. During the accident, the pilot and a camera assistant struggled to free themselves from their harnesses. The camera assistant was recovered from the water several minutes later, unconscious, and later succumbed to his injuries. The accident resulted in one death and two injuries, and the aircraft was destroyed.
The investigation
The investigation focused on the sequence of events leading to the loss of control during the takeoff phase. Investigators examined the standard operating procedures for securing the aircraft on the vessel, noting that while four tie-down ropes are typically used during transit, only the two forward ropes are intended to remain attached until the moment of takeoff, at which point they are to be removed by deck personnel. The investigation also reviewed the weather conditions at the time, which included winds from 090° at 15 to 20 knots with gusts up to 30 knots, and visibility exceeding 20 km.
Findings
- The primary cause of the accident was a lack of coordination with the deck personnel, which resulted in the two forward tie-down ropes remaining attached to the aircraft during the application of power for takeoff.
- The physical constraint of the unreleased ropes caused the sudden, uncontrolled pitch and subsequent capsizing of the helicopter.