Mike, I had a little run in with a railroad crossing arm with our ladder. The result was that I had to completely remove it and take it to a propeller shop (they were the only ones around here who could weld aluminum) to have it fixed. That exercise taught me a couple of things about my ladder:
1. It is pretty flimsy. I'd never consider using it repeatedly.
2. The method of fastening it to the rear fiberglass cap on our MH is marginal at best. When I put it back on, I increased the size of the screws and used good caulk at all of the contact points. It is one heck of a lot more stable than it was. As a sailboat guy who as done many repairs and fastened a lot of load bearing hardware to sailboats, I can tell that there is no real way that I can see fasten the ladder properly. To do that would require backing plates under the screws. I don't think that the material in the rear cap of our RV would hold up well against the kind of reinforcement that would be needed - the fiberglass is just too thin.
Your situation may be very different.
2000 Georgie Boy Landau 36' DP
2005 Saturn Vue toad