http://www.airliners.net/photo/KLM--...06M/1116891/L/
Please click on the link above and have a look at the 747 Body and Wing Gear. It gives a good view of the main landing gear arrangement on the 747. The forward pairs with the higher degree of
"tilt" are the
Wing Gear, and the inner ones with
less tilt are the
Body Gear.
While taxiing, with the Body Gear steering switch on, the Body Gear
pivots left and right opposite to the Nose Landing Gear, so if the nose gear turns right, the Body gear turns left, like a hook and ladder fire truck. If one were to land with one set of Wing Gear not extended, then any turns to that side
could result in the engine cowling making contact with the runway or taxiway.
If the crew did a tower fly by and the tower said the gear was down then that is one thing, but the gear indication should have clearly shown that that gear truck was NOT down and locked. The problem is that the crew took for granted that the morons in the Jeddah tower
know what the gear should/would look like when it is fully extended, apparently not in this case.
The gear tilts when airborne, and gear tilt has several functions "as we all know right", thru the gear tilt switches. But a tilted gear requires a smaller gear well than an untilted gear, so less space needed for a tilted gear when in the wheel well. Rember, do not retract an untilted gear, the landing gear handle is blocked preventing the handle from being selected to the up position when the gear "is not tilted" , then once further troubleshooting and QRH/Checklist's are followed to acertain that the gear is tilted, the Gear Handle blocker could be moved to allow the handle to be selected up.
This crew was lucky that the inboard engine on the malfunctioning gear side did not become an expensive icecream scoop.
