John wrote:
Don't forget, on July 19, 1989 Captain Al Haynes crash landed a DC10 in Sioux City, IA. 185 of the 296 souls on board survived. The failure that caused the crash was "mathematically impossible". Please let me disagree with the last sentence. I think, when "engineers" route the hydraulic lines from both systems so close together that one incident could destroy both systems, that's not '"mathematically" impossible,' it's a probability just waiting for its chance. Ditto the engine that fell off at Chicago, severing both hydraulic systems that kept the flaps deployed on that side. Bad engineering, for sure. In the Hudson River case, everything was done right. (We could abuse the engineers who claim that modern engines are so reliable that only two are necessary because the chance that both would fail is infinitesimal. A four engine plane would probably have kept at least one engine running and let them land on an airport. Engineering decisions have consequences.) Whether you attribute the excellent touchdown that kept one engine from prematurely scooping water, flipping and breaking up the plane to luck or God, I'm sure glad it worked out so well. Ed
