ppruners,
In all due respect to the point of view of Heli-non-Comparitor, please take care with anything he says about certification in general, or the certification details of any helicopter, especially a Sikorsky one!
g33,
We equivilent safety certified one component. The birdstrike certification must be done with tests, almost nothing else will do. When that TCDS was issued, we discovered that we had tested everything exposed on the aircraft to a fairtheewell, but we "forgot" the main rotor pitch links, which are about 1.5" in diameter, and made of solid titanium. It didn't matter that the bird wouldn't stand a chance against that rod, we had to do some pull tests that the FAA approved, in conjunction with loads measured when bird strikes were made on objects of the same diameter and got the equivilent safety approval. To clean that equivilence up, we started up the bird cannon and shot a pitch link about 2 months ago. This was approved on the last issue of the TCDS, which should be posted shortly with that equivilent safety removed.
Other than that one test, the original approval was gained by shooting everything, tail drive shaft covers, tail rotor pitch mechanism, rotor fairings, engine lips, main blade tips and tail rotors. The extensive comparison of test data to analysis was a real research project, and we learned a lot! The bird hits with the force of a 4 Kg sledge hammer at 80 knots, so the upper fairing and drive shaft covers are built as if they were ballistically tolerant.
Regarding window size, we sized ours by taking a Sikorsky engineer who weighs 300 lbs (21 stone - 136 Kg!!) and dressing him in a standard immersion suit, then having him crawl through the openings we proposed. The windows on the S-92 pass this test, and are all push out type. The films of this fellow popping out of the window are a sight to behold! Some rather large Norwegian Union guys also duplicated the test (probably because Heli-non-Comparitor had talked to them) and they were tickled pink with the S-92 windows, which is one of the many reasons why they will be looking out of them on their own S-92's very shortly!