12 May 2009

S-92 Q and A

While it is stamped for internal use only, CBC has posted an internal questions and answers document prepared for use by the oil company officials and Cougar for use at some meetings being organized with offshore workers prior to the resumption of helicopter flights to the three platforms.

The answers are straightforward and leave out information that is still subject to the Transportation Safety Board investigation of the S-92 crash two months ago.

Some answers stand out, though, like this one about gear box warning indications:

Q79. Has there ever been a Gear Box alarm incident before? How was it handled? Was anything different from this incident? Did it happen with the S-92A? (Questions 112, 45, 277)

A. In the entire global fleet of Sikorsky S-92A helicopters, there have been a
total of five incidences related to three types of gear box issues.  Two (including Cougar’s helicopter) related to filter bowl studs, two related to lube oil pump Vespel spline couplings, and one related to overfilling of lube oil. The change from titanium to steel studs as mandated by FAA directive has been completed. The Vespel spline couplings underwent a design improvement that was previously implemented.

or another on the 30 minute run dry issue:

Q81. There has been comments that the gear box should be able to
run dry for thirty minutes, if this is the case why did this not happen? 
(Question 240)

A. Sikorsky states that there is no “30-minute run dry” regulatory requirement for civilian certified helicopters. The S-92AA main gearbox is fully certified, without waiver or exception, to the latest Federal Aviation Regulations (FARs), including Part 29 through Amendment 47. Sikorsky states that total loss of oil is considered an extremely remote event based on system design. Further,that for all gearbox failure modes that are not deemed as extremely remote, continued safe operation of the S-92A helicopter main gearbox has been demonstrated in excess of three hours running time. In the circumstance of total loss of lubrication, a “Land Immediately” instruction is directed.

-srbp-