A couple of years ago I had a situation on a flight from Seattle to Ketchikan. About a half hour out the flight was aborted and returned to Seattle. We dumped the fuel and the landed to lots of flashing lights on the runway.
After a few hours of wrenching on the plane and a test flight they gave us a different one. The results from this as far as any compensation was ZERO.
Good luck getting anything more than the letter.