The gear doors are opened, too, and if memory serves right, that LTU 757 pictured above had a loss of hydraulic and thus the gear doors remained open. Probably that TMA A310 pictured above has the hydraulics checked?
But I'm not an expert, maybe you should better ask that question on the tech/ops forum.
TechRep From , joined Dec 1969, posts, RR: Reply 5, posted (11 years 7 months 2 weeks 3 days 9 hours ago) and read 956 times:
The gear doors cycle back to close when the gear are extended or retracted, so they will not be a factor on landings. On the ground a bypass handle is pulled allowing the gear doors to be opened. Typically, hydraulics is re-applied and the bypass handle is then closed and the doors will slam back shut. On the larger aircraft B747 and DC-10 if your brave enough, you can ride the gear doors up in lieu of no ladder being present. I never felt comfortable doing it but I have.
TechRep From , joined Dec 1969, posts, RR: Reply 6, posted (11 years 7 months 2 weeks 3 days 9 hours ago) and read 948 times:
I forgot to mention in some emergency situations from loss of hydraulic fluid, depending on aircraft, the gear would be allowed to be extended but the main gear doors to conserve fluid resources will not retract back to faired position. So in that case a hard touch down could impact the main gear doors. If an airplane is seen with the gear doors down on approach or while taxiing, then there is some cause for concern.
Klaus From Germany, joined Jul 2001, 21346 posts, RR: 54 Reply 9, posted (11 years 7 months 2 weeks 3 days 2 hours ago) and read 874 times:
Wouldn´t it be a serious design error to have the gear doors big enough to impact the runway on a firm touchdown? After all, ripped-off gear doors might cause additional damage to the aircraft in an already difficult situation...
Klaus From Germany, joined Jul 2001, 21346 posts, RR: 54 Reply 11, posted (11 years 7 months 2 weeks 3 days 1 hour ago) and read 849 times:
When hydraulic lines get damaged in the process (when the doors go, so might the actuators), secondary damage could be possible. Possibly affecting the brake lines. Or leaking hyd fluid being spilled on the hot brakes (possible fire hazard).
I just don´t think an airframe designer could afford to take risks like that. My guess is the doors wouldn´t touch the runway as long as the landing gear doesn´t break. (That would have to include surviving complete tyre blowouts without impact.)
Does somebody have any actual evidence one or the other way? I´m just guessing here...
TechRep From , joined Dec 1969, posts, RR: Reply 13, posted (11 years 7 months 2 weeks 3 days ago) and read 817 times:
If the doors are impacting the ground that hard hydraulic power is of little concern at that point. The design causes the doors to naturally go to the closed position when they impact the ground, if in fact they even can. They will drag maybe but they will tend to bounce up not shear off. The DC9 family, was what I had in mind, they have a brass/bronze stop to cushion impact when they are opened on the ground.