Bell 206-L4 N414RL accident near Gulf Of Mexico, GM

Probable cause

The pilot’s improper takeoff technique that allowed the helicopter skid to drift into a helideck light, resulting in a dynamic rollover.

NTSB analysis

The pilot reported that on approach to the offshore oil platform the wind was gusting from the north. During approach to the helideck, he turned the nose of the helicopter to the northeast, so the disembarking passengers were near the stairway. Later, as he attempted to takeoff, the front skids lifted off the helideck and the wind from the north pushed against the helicopter. The skids became stuck on the helideck and the helicopter rolled over. The pilot was unable to regain control of the helicopter as it continued to roll off the helideck. During the uncontrolled descent, the pilot activated the emergency floats and the helicopter impacted the water. The occupants egressed the helicopter and were rescued from the water.

Photos of the helideck revealed the metal safety skirting was damaged and partially separated.

The operator’s chief pilot stated to the Federal Aviation Administration (FAA) inspector that the pilot stated he made his approach from the south and terminated to a hover, rotated the nose right 45° which put the helideck stairs off the right side of the helicopter’s nose. During the subsequent takeoff, the aft right skid of helicopter likely contacted the helideck and helideck light, which resulted in dynamic rollover. He also reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

The operator’s General Operating Manual (GOM) states that platform takeoffs should always begin from a stabilized hover and as into the wind as much as possible.

Postaccident examination of the helicopter revealed damage and witness marks to the aft right skid and did not reveal any preaccident mechanical malfunctions or failures that would have precluded normal operation.

It is likely that the pilot’s improper takeoff technique allowed the helicopter to drift toward the helideck light, then when the skid contacted the light, that acted as a pivot point and resulted in dynamic rollover.

Text from the NTSB. Open the NTSB docket for CEN23LA064 for the full record.