Bird strike possible cause of helicopter crash
The NTSB is focusing on a bird strike as the cause of the Jan. 4 crash of an S76 helicopter in the Gulf of Mexico. The helicopter was transporting Royal Dutch Shell workers to an offshore oil platform in clear weather. The NTSB quickly ruled out most of the more common causes such as fuel starvation or mechanical failure. The reason for the crash puzzled investigators, causing Shell to temporarily ground its entire fleet of S76 helicopters.
The helicopter’s cockpit voice recorder captured a sudden loud bang followed by wind noise. One second later, the power from both engines dropped considerably. According to the NTSB, the theory is that debris struck the throttles, retarding them. Investigators are working to confirm this theory and have sent some of the material found in the cockpit to experts to determine if it came from a bird.
According to the manufacturer, operators sometimes replace the windscreen with a weaker acrylic version to save weight. There is speculation that a letter is forthcoming to warn operators of the increased danger of using these windscreens. Petroleum Helicopters, who operated the helicopter, has not commented.
This model helicopter is very popular with corporate flight departments and oil companies for transporting workers to offshore platforms. If the NTSB confirms the cause as a bird strike, it would have happened two weeks prior the bird strike that forced a US Airways airliner to ditch in New York’s Hudson River.
February 17, 2009