BELL 206-L4

The commercial pilot was attempting to land his single-engine helicopter on a fixed production platform helipad when the main rotor blades struck the corner of an oil derrick that was partially positioned over the helipad. The pilot lost control and descended inverted into the ocean. The emergency external floats were not inflated, and the helicopter sank. At the time of the accident, a mobile jack-up rig was mated with the fixed production platform. According to the company that owned the production platform, the helipad was closed and all flight operations were being conducted from the jack-up rig’s helipad, which was larger and unobstructed. However, at the time of the accident, the production platform’s helipad was not marked closed and no notice to airman (NOTAM) had been issued to notify pilots that the helipad was closed. There was also nothing in the operator’s flight operations manual that would have restricted the pilot from landing under an obstruction. Other company pilots were aware that this helipad was a flight hazard due to the encroachment of the oil derrick, but it was never reported to management or via the company’s internal safety notification system. A review of company flight manifest records revealed that the pilot had flown to this platform on several occasions, including 2 days before the accident, and landed on the jack-up rig’s helipad. It could not be determined why the pilot decided to land on the smaller and obstructed helipad rather than the jack up rig’s larger helipad just 2 days later. Examination of the helicopter and engine revealed no preimpact mechanical failures or malfunctions that would have precluded normal operation.