Accident
The pilot reported that after lifting off from the offshore platform, the helicopter reached 60 knots of airspeed and climbed to 200 feet above ground level (AGL) before initiating a left turn. During the turn, the aircraft began to descend and subsequently struck the water.
Witness Accounts
Witnesses located three decks below the helideck observed the helicopter as it departed the helideck in a steep left bank with a nose-down attitude. The aircraft continued in that attitude until it impacted the water. The left front seat passenger confirmed the aircraft's attitude during the descent.
Investigation
Examination of the engine and rotor drive train revealed no evidence of pre-impact failure or malfunction. The pilot did not specify the reason for the nose-down maneuver.