Landing gear issues.

For those of you who aren't passingly familiar with what this is all
about ... someone was trying to turn AirBus' great big, brand-new,
A380 aircraft a little too sharply (we don't know whether under it's
own power, or while it was under tow).

AirBus elected NOT to make their main landing gear system (four
separate gear with four wheels apiece) steerable. Why? You save a
considerable amount of weight -- not to mention some serious extra
cost -- by not doing so. There is a trade-off, however ...

When you have non-steerable gear that are configured like they are on
this aircraft, you have scuffing/skidding going on whenever you turn
the aircraft. This isn't an unusual design for a wheeled vehicle,
though.

For instance, a dual-axle semi-trailer does the same thing
when it's being maneuvered sharply within a warehouse parking lot.
What makes the A380 so special, is the incredible amount of weight on
each huge tire, in conjunction with the widely-spaced gear. In
concert, these two aspects considerably magnify the inherent problem
to the point where the asphalt (not just the rubber tire) is taking
it in the shorts ... not to mention the stress and overload that's
happening to the entire structure between the tire and the gear
attaching points in the wing structure. !

Note the apparent bending of the gear in one of the shots! No, Mildred,
that is NOT a good thing to be happening to your aircraft's main landing
gear. Unless they're making everything out of rubber, those stress loads
have GOT to be off the scale!

As new-aircraft design problems go, this will likely prove to be a
very expensive one for AirBus to deal with. It's either that, or the
aircraft will only be able to operate in and out of airports that have
the extra fifty-acres it will need to get safely turned-around. It'll
be interesting to see how they solve this one.

Note: SLAC member Captain Jim Theobald informs us that the main gear on a
Boeing B-747 tracks the nose gear so it doesn’t have the above problem.

Click on Pictures to Enlarge