On March 12, 2009, a Sikorsky S-92A helicopter on a flight to the Hibernia oil production platform had a total loss of oil in the transmission’s main gear box. The flight crew descended to 800 feet and headed towards St. John’s. About 35 nautical miles away and during an attempted ditching, the helicopter struck the water in a high rate of descent. One passenger survived with serious injuries; the other 17 occupants of the helicopter died of drowning.
The Transportation Safety Board of Canada conducted an investigation into the incident. The Board just released a report on its findings and recommendations. Here are the highlights.
The Board’s investigation identified the following safety issues:
- Category A rotorcraft certified under the “extremely remote” criteria may not be capable of continued operation for 30 minutes with only residual main gear box lubrication.
- In today’s operating environments, it may now be technically feasible and economically justifiable to produce a helicopter that can operate in excess of 30 minutes following a massive loss of main gear box lubricant.
- Helicopter crews and passengers in Canada remain at risk when helicopters are operated over the sea when it’s in a state that exceeds the capability of their Emergency Flotation Systems.
- Without a supplemental breathing system, occupants have very little time to get out of a submerged or capsized helicopter before breaking their breath-holds in cold water.
The Board made the following recommendations to address the identified safety issues:
- Removal of the “extremely remote” provision from the rule requiring 30 minutes of safe operation following the loss of main gearbox lubricant for all newly constructed Category A transport helicopters and, after a phase-in period, all existing ones.
- Assessment of the adequacy of the 30 minute main gearbox run dry requirement for Category A transport helicopters.
- Prohibition on commercial operation of Category A transport helicopters over water when the state of the sea won’t permit safe ditching and successful evacuation.
- Imposition of a requirement that supplemental underwater breathing apparatus be mandatory for all occupants of helicopters involved in overwater flights who are required to wear a Passenger Transportation Suit System.