I wouldnt trust a repair on plastic.They think they know what time X will be on these airframes.I’d hate to be the one that finds that out the hard way.
To play devil’s advocate. I remember when everyone at the gun show said the same thing about the Glock. Something along the lines of “cheap plastic piece of crap”. Everyone is making plastic guns now..... I wonder why?
I used to work in aerospace. Airliners made from aluminum alloys have a definite fatigue life. Past a certain number of cycles, they’re no longer trustworthy without extensive inspections and/or overhaul (to include re-skinning or replacement of structural members). I’m not that familiar with carbon fiber composites, but I’ve heard that properly designed and fabricated composites are stronger by weight than steel, and have have better fatigue life than aluminum alloys. I’m sure the 787 structures have been extensively tested at the coupon, and airframe level to validate predicted life; that’s how we did it in the rocket engine business. I would be more than willing to fly on a 787 versus an old plane. Remember the Aloha Airline 737 that turned into an open top airplane? That’s metal fatigue in action.
There is no highway in the sky. But I would be a heck of a lot more confident in a high-cycle carbon fiber structure than I would in a high-cycle aluminum structure. Composites may have issues, but aluminum metal fatigue is a known and even bigger issue.
The big thing about composites is build quality. I trust Boeing to get this right.