I have nothing but the highest respect for the professional work airline mechanics do. But this whole another set of eyes argument doesn't hold water in my view. Many other airlines have gotten rid of mechanic R & D and they are not suffering because of it. Will there be a learning curve? Absolutely. It'll take people time to learn the new function. Just like it would for de-icing or something else. The second set of eyes argument is nowhere near enough justification to have mechanics performing R & D when the costs are astronomical.
You cannot just simply blame the company for allowing it. Mechanics doing R & D was born of the regulated era, when airlines passed along their costs to the consumer. That is where all the featherbedding comes from. Unions knew they could get away with inflating their contracts with such inefficiency (to fatten the rolls, so to speak), because airline managements would simply petition the CAB (prior to DOT) for fare increases to cover it. That was how the game was played. But once de-regulation hit, airlines were restricted in their ability to pass along cost to the consumer because airlines were now forced to compete against each other for revenue at the lowest possible cost. But unions held onto these sacred cows because getting rid of them meant lots of job losses. I can certainly understand that. But we're in a completely different time now. Things have changed forever. Either rules like this need to go, or the airlines in question will go. It's that simple. There is simply no tolerance for that kind of inefficiency anymore. The depressed revenue stream won't support it. I sympathize with anyone whose job would be lost because of it, but these are things kinds of things that simply must be changed if your airline is to have a future.
But please do not hang onto the safety will be compromised argument. There are plenty of airlines that do R & D without mechanics and their safety records have not suffered. As I stated earlier, with any new function, there will be a learning curve. But I seriously doubt US Airways safety record is going to suffer.