Commercial, Military

S-92s Gearbox Certification

By Staff Writer | April 7, 2009
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The Globe and Mail, Canada’s second largest daily newspaper, claims to have obtained official documents showing that during its initial design certification process, the Sikorsky S-92’s main rotor gearbox failed to pass the FAA’s standard “run-dry” tests. During the test, the manufacturer must prove that the gearbox can continue operating 30 minutes after running dry of its oil. The Globe and Mail said the documents it has shows the S-92 gearbox seized up prior to 30 minutes, but received FAA certification under a relatively obscure regulation that says the test need not be passed if the manufacturer can show the chance of losing all oil is “extremely remote.” Of the 100 S-92s delivered to date, a loss of gearbox oil has been linked to one emergency landing by the crew of an S-92 in Australia in 2008, and was mentioned in the mayday call made by the pilot of a Cougar Helicopter that crashed on March 12, killing 17 aboard. Industry experts say two oil failures in a fleet of 100 aircraft in the five years since the model’s introduction do not rise to the level of “extremely remote.” Sikorsky says it is not allowed to comment on the report because the accidents are still under investigation. For Related News


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