Gearbox Oil Pressure Blamed In S-92 Emergency

 - November 1, 2006, 11:33 AM

Pilots of a Sikorsky S-92A from Norway’s Norsk Helikopter put out a Mayday call one day near the end of March, after being warned of a major drop in main rotor gearbox oil pressure while approaching an oil platform. The pilots made an emergency landing on the Veslefrikk B and none of the 19 people on board was hurt.

Norsk commercial director Geir Tynning told AIN that the cause of the pressure drop appeared to be the failure of nonmetallic vespel splines on the drive of one of the externally mounted main rotor gearbox oil pumps. The oil remained inside the gearbox housing. “Until a root cause for the incident is identified,” he said, “a 50-hour inspection [of the oil pumps] has been implemented.”

Tynning confirmed that both of the company’s S-92s had resumed flying for up to eight hours a day. “Feedback from customers and passengers is extremely good, particularly the improved passenger comfort and reduced travel time.”