Originally Posted by
Miles Gustaph
It is this fundamental inability to control the aviation operating environment in its totality that separates us from other disciplines. I have talked with mechanical engineers who are critical of the aviation industry and its perceived inability to produce gearboxes that never fail. Ask them to explain how they would manufacture a gearbox that is a primary part of a large, variable load path, is subjected to a horrible amount of vibration and doesn’t weigh as much as a truck. And if it goes wrong could kill a dozen plus people, I haven't heard a credible answer yet.
Miles, well said, but I'll add a different angle to this point. Even fixed wing design and production folks often don't "get" how helicopter design and production and operation is orders of magnitude more complex/difficult. (Per pound, it's about 10x as expensive to create a helicopter than a fixed wing aircraft). The continual interaction in all three axes of loads, on the flight controlling surfaces and on the airframe, as well as the vibration problem to sort out, complicates achieving MTBF goals.
Wear and fatigue are facts of life. Where the commercial market finds itself bumping into sharp edges is in seeking to increase MTBF for major dynamic components while also chasing that weight reduction problem. If you have to change the main transmission every 500 hours, as opposed to every 2500 hours, has a big impact on how well your transport service operates, or if it even survives. Designing and maintaining in good health the critical systems is a never ending effort.
The other matter, and IMO the critical matter in a mature aircraft, is how the system is set up to warn the operator of impending failure or in many ways present wear and tear as "graceful degradation." What makes this accident such a shock to the system is the few seconds of warning and then
it all came apart on a fairly mature aircraft design.
Monitoring of dynamic component health and usable signs of things wearing out: that's were accident prevention may learn something valuable when this accident is fully understood.