This is very pertinent. Boeing designs its landing gear to shear off under excessive vertical loads; this is far safer than having it break the wing spar, as apparently happens on the MD-11. I think this goes back to when McDonnell took over Douglas; McDonnell had never designed anything except military planes, and if they met specifications then everyone was happy. Boeing, Douglas, and Lockheed, however, had learned that when designing airliners you made it as safe as you could, period. The regulations were regarded as just the starting point. I am convinced that many of the problems with the DC-10/MD-11 come from the fact that the military people at McDonnell were in control of the company, and the Douglas people who really knew how to build an airliner were not listened to.