Departure and Initial Flight
A commercial pilot with 1,936 hours of flight experience departed at 0705 with three passengers for an oil platform in the Gulf of Mexico. Prior to departure, the helicopter was serviced with 50 gallons of fuel, estimated to provide approximately 1 hour and 50 minutes of flying time with no reserve. The pilot reported landing on the first platform at 0829.
Inspection and Refueling Issues
After landing, oil was observed on the side of the fuselage, and the pilot could not see any indication of the transmission oil level. A mechanic determined that the transmission had been over-serviced, and residual oil had caused the streaking. The pilot informed the mechanic that he did not have fuel for a 30-minute ground run. The mechanic suggested a 5-minute run and a 5-minute hover after engine cowlings were in place. A second pilot offered to obtain fuel, but the accident pilot declined, stating he could do it without any problems.
Subsequent Flight and Accident
The second helicopter departed at 1313, leaving the accident pilot and mechanic to complete the engine run and flight to a second oil platform for refueling. The accident pilot reported his departure at 1359 and landing at 1410. As the helicopter approached the platform from the south, it made unusual turns left and right before straightening up toward the heliport. Just before reaching the heliport, witnesses reported the helicopter sounded like it lost power and began dropping rapidly. It descended below the platform's living quarters, and witnesses heard the helicopter contact the platform and fall into the water. The emergency floats did not deploy.
Post-Accident Examination
A visual inspection of the powerplant revealed no obvious abnormalities. The fuel tank and bladder were breached by impact. A small amount (approximately 1 teaspoon) of water/fuel mixture was found in the fuel line between the firewall check-valve and fuel nozzle. The fuel line between the fuel control and firewall check-valve contained no fluid. The fuel filter canister contained a fluid that quickly separated into about a 90/10 water and fuel mixture; laboratory analysis later identified the fluid as saltwater and fuel. The fuel line between the fuel filter and airframe bulkhead contained about 3 tablespoons of mostly water. The engine was disassembled and inspected; both compressor and turbine sections exhibited no abnormalities. The engine accessories (fuel control, power turbine governor, fuel pump, and fuel nozzle) were bench tested with no discrepancies found. Drive and flight control continuity was established to both main and tail rotor systems. In the cockpit cabin, the pilot's seat and shoulder belts were found fastened, while passenger seat and shoulder belts were unfastened. The landing gear emergency float system was found in the unarmed position. The caution panel was examined; two bulbs (fuel pump and engine-out annunciators) had stretched and broken filaments, while the low-rotor annunciator bulb had stretched but not broken filaments.