Thrust reversers

[skyking]

ground loop is not really a cartwheel, it is a spin on the ground that usually involves a wingtip down on the pavement/grass. When it's all done the plane is usually travelling in more or less the same direction after 360 degrees of revolution, missing some parts and pieces.
Tailwheel airplanes are more prone to a ground loop. The center of mass is aft of the main wheels, and has both a desire and propensity for changing that role
The drag of the tires, coupled with a poorly controlled yawing moment leads to a skid, touching of a wingtip, bending of the gear leg on the down-skid side, and then it typically gets straightened out again.
Many of the early tailwheel trainers had a multi-spar wing design, utilizing a small spar outboard called a jack spar. This piece took all the damage and was more easily repaired/replaced.

 

[LTC8K6]

Gents,

Vmcg is why. Vmcg = Velocity, Minimum Control, Ground

A failure of an outboard thrust reverse mechanism would create a yawing moment greatly in excess of the aircrafts' control surfaces and/or nosewheel steering to maintain control.

In short, a failure would cause the aircraft to veer off the runway and potentially ground loop.

Other aircraft that have outboard reverse typically have a derating mechanism to restrict total thrust available below a certain speed.

Hope that helps...

Signed,
An aerospace engineer, and a pilot...

The A380 designers would have taken that into account though, if they decided that it needed the outboard reversers, so that can't be the reason they aren't present, imo. There's no technical problem preventing the A380 from having outboard reversers as far as I have read.

FOD, and weight and expense savings, and the fact that no reversers are necessary at all, are the primary reasons, imo.

 

[LTC8K6]

http://cdn-www.airliners.net/aviation-photos/photos/1/2/1/2569121.jpg

There is an A380 in the rain using reverse thrust. You can see again that the rain is being pushed forwards.

 

[Humpy]

This thread wasn't anything like what I hoped it was going to be like based on just the title.