espresso drinker:
The question is surely it's certification should have been revoked after the second fatal accident, or are the steel studs all that was needed to satisfy the 'extremely remote' loop hole added to the certification requirements after the S92 failing the dry run testing?
Well of course the S-92's airworthiness certificate should have been revoked following the Cougar crash! Of course. That's not even in question anymore.
SAC managed to convince the FAA guy (whose name we don't need to mention because everyone already knows who signed-off on it) that the ONLY possible source of a leak of transmission oil would be the lines leading to the oil cooler. Filter won't/can't leak...driveshaft inputs can't leak...the mast seal can't leak...the list goes on!
And the (unnamed) FAA guy said, "Yup, I agree!" But if they were using the S-92 design to justify that "extremely remote" crap, they had no historical base to draw from. If they (SAC) were using an industry-wide base for loss of transmission oil, they STILL were not on solid ground, because such things happen more than
extremely remotely. (Admittedly they don't happen often, but "extremely remote" is a defined term.) SAC took the awkward wording of section 29.927(c)(1) and used it to their financial advantage.
So no, the S-92 does not IN FACT meet the requirements of FAR part-29 when it comes to the transmission. I would venture to say that there is no helicopter in existence that would qualify under that "extremely remote" clause. Why do we care? Because when you design an aircraft that's going to take LOTS of people out over some very inhospitable parts of the earth, then you are -
and should be - held to a higher standard.
We know now that the S-92 transmission cannot withstand a complete loss of oil. Sikorsky admitted that their testing showed (and Cougar proved in the field) that you get "about" ten minutes of run time with no oil. This is undisputed. What's truly disturbing to me is that so few people seem to care. Pilots in particular are so very cavalier about this, as if it's a trivial or inconsequential point. It boggles my already-feeble mind.
What it boils down to is that it would have been economically unfeasible, unrealistic and unreasonable to summarily ground the S-92 fleet and force Sikorsky to redesign the transmission. Passenger safety takes a back seat to money. It's not the first time this has happened in aviation. Shamefully, it probably won't be the last. Personally, I think we owe the paying passengers -
and the pilots who fly them! - more than that...better than that.
I mean, why have rules at all if exemptions and "work-arounds" are allowed and applied so freely?