What is it that tends to flip over DC10/MD11s, or at least break the wing on hard landings? We have this, the Martinair crash in 92, FedEx in 97 and a couple of others, I believe. NTSB once expressed concern about certification standards for landing gear, and the fact that this type, as well 757/767, accounts for a gear failure mode in the rearward direction, but not in the upward, which may have a role in the gear on hard landings snapping off the wing. So what's the culprit, some tendency in these planes to lure pilots into over-hard landings, or an inadquate gear failure mode, or a combination?