Mars
Its my understanding that the S92 does not have true 30 min dry running capability. In order to meet the certification requirements it relies on retaining some oil in the sump by shutting off the external pipework. This fudge clearly only works if
a) the leak is from something other than the main gearbox and
b) the pump(s) are still running.
If there are no pumps working, dry running time is unknown but less than 30 minutes.
In this case it seems that the pumps had not stopped working altogether, as apparently there was still about one tenth of normal pressure showing on the gauge, and with the destination platform being so close they got away with it. With the drive to both pumps presumably slipping, I doubt it would have been long before the wear caused the pumps to stop altogether.
I must say I didn't realise that the pump drive splines were plastic - I suppose this explains how they can wear out on an aircraft with only about 200 hrs since new. Its a bit worrying though!
It will be interesting to see whether the perceived certification fudge that allowed the S92 to enter service without true 30 minute dry running time will come back to haunt SKy sooner than we thought!
RJSquirrel
I believe you are not correct, both pumps lost drive and both spline couplings show severe signs of wear/slippage according to my rumour source. So it could have been a disaster (well at least a ditching) but fortunately circumstances were on their side.
HC
Last edited by HeliComparator; 7th Apr 2005 at 22:13.