4 ms·United Airlines Flight 93.by Cushman 16y agoUnited Airlines Flight 93.arst 16y agoWas the cockpit door on UA93 reinforced? I can't recall ever hearing/reading that.tptacek 16y agoThe cockpit doors on UA93 were not reinforced.Cushman 16y agoI'm assuming "in the history of air travel" means "ever" not "since we started reinforcing them."