Weight & Hull strength variations between models

[Anticept]

Actually I think aluminium is harder to fix. Putting in a patch plate is easy, but to form, bend, and plan a real repair layout takes a lot of math and skill. If you screw up, you generally have to start over.

 

Composites take longer and are more sensitive to incompetence (because a bad layup is difficult to distinguish from a good one), but it is very forgiving in that you usually do not have to redo everything.

 

The exception is if you are using a minimalist composite construction in a major repair or alteration (meaning using the minimum amount of material for the design). You have to use tensile calculus and a powerful computer to run the math then. People don't really do minimalist design except in competitive environments because it requires high levels of engineering knowledge, and skill to construct it.

[Doug G.]

No wonder most airplanes are made from aluminum. That stuff is easy to fix.

It wasn't always the case. There has always been a debate about the most effective British fighter - Spitfire or Hurricane. One off the factors was that the Spifire was made of metal and had more downtime because of the difficulty of the repairs. The Hurricane on the other hand was plywood and there were more woodworkers than metal workers so there was less downtime.