Apologies to anyone if I've stepped on toes and whose patience may have been tested, particularly in making the Mods earn their salary
, but it was to seek the truth ie to what standard the box was certified.
HC #1270
Nick Lappos never said that the S92 had 30mins dry running time
At post #62 (20 December 2002) Nick posted a Sikorsky press release "Sikorsky S-92 Awarded FAA Type Certification" which has in part,
Breaking new ground for medium-weight helicopters, the S-92 provides unprecedented levels of safety and reliability. It is the only aircraft in its class certified to the latest specifications for flaw tolerance, bird strike capability and turbine burst protection. In addition to its civil helicopter capabilities, the rotor system and dynamic components are designed to meet the UH-60 BLACK HAWK ballistic tolerance requirements and all gearboxes are capable of running 30 minutes after loss of oil. Corrosion protection meets or exceeds current maritime standards.
So it would seem to me that the box was originally certified to the 30 minute standard, else why would some one of Nicks standing post otherwise. I'm sure he would have had something to say if it was mere hyperbole inserted by marketing as suggested by some. Secondly, I doubt a corporation of Sikorskys stature would put into print something which they know to be false, litigation being what it is. Obviously the original certification would seem to have been overtaken by events. That the box may be having trouble in the field at the moment is but one of the many hiccups that an aircraft can go through in the maturing process.
HC #363
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.
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!
Interesting last para HC.
HC, with respect to earlier comments (now deleted, regarding actions based on sources of information other than contained in the RFM) what I was alluding to is much better said by Nick in his post #964. I've highlighted what I think are the thought provoking elements.
I wrote the S76 checklist, and in the intro paragraph to Chapter 3 gave the pilot the latitude to be more than a sweaty flight-manual reader. The difference between airmanship/wisdom and memorizing flight manuals is the difference between pilots and stick wigglers, IMHO. If the flight manual words say "XXX" and you think you must do it, then do so. However, if the PIC decides to actually try some airmanship, in many cases it would be welcomed.
The ease of saying and preaching (in the ease of a Sunday at the keyboard criticizing your fellow pilot) blind obedience to the flight manual, "land immediately" is often confounded by the actual conditions, and by the fact that the aircraft is still flying nicely, even if a few lights are on. I am reminded of the American Airlines DC10 Chicago engine drop-off accident: In simulator trials afterward, the crews that obeyed the checklist and slowed to Vy (while they were climbing at over 2000 fpm before the slow-down) all died like dogs, those that flew wisely like airmen landed successfully.
I do not know what happened with this specific aircraft, at all, but I am lead to believe from 212man's posts that it did not lose all or most of its oil, rather, it might be that it had an oil leak. Any pilot who ditches a load of passengers with an oil leak (even if he memorized the flight manual in that case) might deserve to be ppruned to death, afterwards.
212man, any comments?
A second illustration of what I mean:
The Air Florida National Airport icing crash occurred because the crew obeyed and believed the EPR gages in spite of the fact that they had no climb and were about to hit the ground. They were gloriously slaved to the checklist and the flight manual, and their slavish unairmanship doomed their passengers. Had they simply pushed the throttles up, they would have climbed. The difference between thinking and memorization might be a problem in some cultures (frankly, I am about to get into PPRuNe trouble here) the typical European attitude that the lords of the flight manual and the CAA know more than mere vassels. This religeous following of every word is more likely to lead to airmanship problems than the attitude that these pubs are guidelines for smart people to follow, but not slave themselves to.
Of course the trick is to know when to be smart and when to be a slave, for the Monday morning quarterbackers will have you for lunch.
The official report into this most unfortunate accident will make for interesting reading, will be lessons aplenty for all I'm sure.
Thank you all for your PMs - you know who you are and I'll not reply individually.