Plane to jetway: Can I have my door back?
 

At DFW Wednesday morning, inbound AA 777 rolled back 200 ft (really? isn't that a typo?) just before passengers started deplaning. You know where the door isn't now.
Sky Talk: American 777 loses door at D/FW

Follow the link and find another forum that has a resident idiot posting rubbish.

But the photos are interesting.

Parking brake? Whatever happened to chocks? :confused:

TV news story says wheel chocks were not set, and plane rolled back 200 feet while passengers were disembarking, snapping off the door against the jet bridge. Amazing that no one was hurt.
See: Door Flies Off American Airlines Plane

Rolled backwards 200 feet? I guess that's a ramp that is really a ramp!

I have had one occasion when the chocks slipped on a greasy ramp after the brakes had been released! Fortunately we noticed as we were conducting post flight checks etc and were able to reapply the brakes before the a/c had rolled a short distance. Luckily there was no damage other than the workload of filing an occurrence report at the end of a very long day!

What sort of incline does this ramp have that it would cause an aircraft at (presumably) a complete stop to roll backwards 200 feet?

Even though a wheel or axle may seem to be completely rigid, there is an awful lot of torsional energy stored in one that is braked to a stop -- especially if the final braking was severe. My guess is that this energy was held in by the final braking, and was only released when pressure in the hydraulic system bled away after the engines were shut down. It probably took a couple of minutes before enough force to overcome the static friction of the tires was accumulated, but after it did, the roll began.

OK, I'll bite. I can visualize the torsional energy thing. But when the brakes are released the torsional energy would actually make the aircraft go forward until it is dissipated, not backwards. So either its the rocking out of snow effect (where going forward against an incline makes it easier to go backward etc.) or its more simple - its on a wicked slope and they forgot to chock the airplane. I go for simple.

P

I'm not sure I understand the 'torsional energy' idea. Blown downwind perhaps?

I find the '200 ft' roll a bit implausible too. Wouldn't someone have noticed? :confused:

What was the "off-blocks" time Captain???:}

parking brake malfunction
 

DGS is used at DFW gates. No guideman required so chocks not installed until ground handlers show up. Parking brake valve malfunction and A/C rolled backwards. I imagine some procedures will change.

jj

I remember when there were lots of competent mechanics waiting for a plane to park...and that chocks in was a signal from the ground crew...then and only then would you release the parking brakes...even then it was a gentle process and if there was any roll, bam the brakes were back on.

My good friend checking out in a DC10 at the same airline as a captain released the handle before the brake and it rolled into the jetbridge. He had been in the right seat so he forgot about how to properly set the brake.
**** HAPPENS.

A couple of questions for the Euro crews that use the parking systems which I've seen in places like Madrid,

Is there a requirement for a member of the ramp crew to man some sort of a stop signal button as an aircraft approaches the gate? Is there also a requirement to chock an aircraft after parking with the auto system? Is an aircraft allowed to park using the auto system without any ramp personnel being present at all?

Yes it would. And the release would have to be sudden to generate an impulse strong enough to set the aircraft rolling. A slow bleed-off of brake pressure and the aircraft would simply ease forward a distance commensurate with the amount the axle was twisted. I would guess mere centimetres.

I thought that all you experts out there would realise that most parking bays are built on an upslope of about 2%.

Why?

It makes it so much easier for the tug to push the aircraft back and it also makes it easier for those aircraft that are capable of doing so to power back by using reverse thrust without using a tug.

This has been discussed many times in the past on pprune (wake up those of you who are sat at the back of the class).

Where? The UK?

Maybe at some brand new well designed terminals in the US, certainly none that I can think of. I think with lowest bidder contracts, we're lucky of the slope is +/-2% in any direction :rolleyes:

Everywhere I go around europe the operator won't connect the jetbridge until the chocks are in place

Silvertop

clearly the lously ground crew were having a fag :mad: