|Quoting Air2gxs (Reply 7):|
The oleos are already at full extension when the enter the gear well. Thus, when the gear is extended there should be no noise from shock strut (oleo) extension.
|Quoting Tdscanuck (Reply 10):|
There are a (very) few airliners that can retract the oleos prior to stowage for space reasons
The A330 / A340 has a gear shortening mechanism on the wing gears. The external crank mechanism for this can be seen just ahead of the rear wing landing gear trunnion point in this photo.
What you both say is true however. The pressurised nitrogen and landing gear fluid are housed in a "shock cartridge" that is free to slide up and down inside the main landing gear casting. Thus, when the A330 / A340 wing landing gear retracts, the crank pulls the sliding shock cartridge into the main landing gear casting via a mechanical linkage internal to the landing gear casting. The sliding shock catridge in turn pulls the inner cylinder, bogie beam and hence wheel and brake assemblies towards the main gear casting as well. The end effect is a physical shortening of the wing landing gear.
The internal mechanism is so arranged that upon extension of the wing gear, an overcentre lock is formed inside and against the wing gear main casting upon full lengthening of the gear. This overcentre mechanism locks the sliding shock cartridge inside the main gear casting, and allows it to take the landing shock as well as the weight of the aircraft.
I not too sure about this one. I am quite cetrain that the A342 / A343 centre post does not shorten. I am reasonably sure that this is the same case with the A345 / A346 centre gear as well.
One point of interest seems to be that all Airbus oleos are of the double chamber design, which supposedly gives smoother absorption of landing shocks.