The a340 can fly with the centre gear inhibited, as the only function it carries is for increasing the MRW of the aircraft. With the gear in the stowed position, it has basically the same structural weight limitations as the A330.
In fact, in case of a gear extension failure with one of the main bogies, it is advised that the pilots do a gravity extension, as the centre gear remains in the wheel well in that instance. The gear cannot support any shock weight, and to have it down with one of the main gears up can cause more damage than it does to prevent it. Happened to a VS
340 a while back, this has.
correct me if i am wrong but wasnt that the center gear of a CX A340?
i have seen pictures of one without the main central gear assembly.
There are more specifics to that incident, but I really shouldn't be talking about that here. However, the aircraft is back in service, with no problems whatsoever.