757 flying on the ground?

[Guest A32X]

Sirs,Please read this article;http://news.bbc.co.uk/1/hi/world/europe/3143237.stmDoes anyone know what light was on in the cockpit?BTW - Does PIC767 model the light? ;)Regards,

[Guest Mark McG]

Sensationalist Guff.

[Guest ACA856_at_work3]

Reading some of the replies....guff is an understatement. People really are sheep when they travel. I can't believe 13 people were stupid enough to think that their lives were in danger.I guess I am biased being an aviation freak. Last I heard, the odds of being in an airline incident were 1 in 27 million, and even then you would have a 1 in 3 chance of surviving an incident. I beleive the numbers were...if you flew in a different plane everydat, 24 hours a day, for 27,000 years...you would have a 1 in 3 chance....and the people cross the road without looking everyday are the same people who refused to get on that plane.Rob.

[Guest A32X]

Some people are scared of flying as it is; the situation must not have helped them. I can believe 13 people did not travel.Anyone know what the exact fault was?

[Guest ACA856_at_work3]

Ian Riddell will post a picutre and description shortly :-), but my guess is it is some kind of micro switch that determines if there is weight on the wheels or not, thus determines if the aircraft is in the air or not....it's not like the engine was falling off or something. People will drive with their lights burnt out on a dark road...but they won't get on a plane the Captain tells them is safe. It is just irrational...so is the fear of flying I suppose.Rob.

[Guest A32X]

So if the aircraft had to abort its take off run it wouldn't be able to depoly the reversers becuase the aircraft thought there was no weight on the wheels? Also, I'm guessing you could retract the gear on the ground too?Was it just a faulty light in the cockpit?Regards,

[Guest ACA856_at_work3]

...and reversers are not part of the MEL as far as I know (depends on gross weight and airports involved I suppose).Ian Riddell is the man to answer your other questions. I know 767/757's fly with reversers INOP more often that you think. My buddy at Flight Ops ACA lives and dies by the MEL. He says their 767's are getting old and used a lot. Galley configs also cause him a lot of grief. A lot of their 767's will go to charter ops until they fall apart. Their 747's are gone by October 1st, or so I hear. :-( When you see aircraft land with no roof (Aloha 737), or no belly (United 747), then one tends not to worry so much about a bulb :-) The United pilot said "I did not land that plane, God did". A little hairy on that one I suppose. The cargo door blew off and cause a bit of fuss.Rob.

[Guest A32X]

Can someone post a MEL? (Minimum equipment list right?)

[Guest obk]

Guy's...Read the news topic again, it was the light that was faulty...not the air/ground logic.

[Guest Mark McG]

A32X,http://www.pprune.org/forums/showthread.php?threadid=98938This may be a more appropriate thread for you to get the answers you are looking for.

[Guest Gixxer_54]

"It indicated that the aircraft was airborne when it was still on the ground." (said then englishman!)not very informitive if you REALLY wanna know what light it is. i never knew they had a light for that ;)http://img.villagephotos.com/p/2003-8/328522/siggyav1.JPG

[Guest ilh]

Come on! How else would the pilot know they were on the ground if there wasn't a light?Lee Hetherington (KBED)

[ACA857]

LMAO!

[Guest]

Well, i have the 757 MEL in front of me and there is nothing relating to the air ground logic system that can be MEL'd and as far as gear indicator lights, if there is a fault in one of the gear position indicators, the MEL has a long process of testing the aircraft while siting at the gate, involving opening the gear doors and performing tests in the E/E compartment. I have never heard or hope that no commercial pilot would ever taxi really fast and then slam on the brakes to redistribute the luggage, especially with passengers on board. At northwest, the pilots are not even allowed to reset a circuit breaker or replace a light bulb, maintinence does that. A commercial pilot is not a test pilot, and from my experience with most line pilots, they do not have nearly enough training or expertise to fix any problem like the one explained. I almost don't doubt the passngers that got off. If my flight crew acted like that, i would not want to get back on either, and I am an instructor in the aircraft.My 2 cents

[Guest Ian_Riddell]

"Read the news topic again, it was the light that was faulty...not the air/ground logic."Before I comment on this one, I must say that I am highly un-qualified to do so. Not only do I not have any engineer licences on a 757, I haven't been near one! Whilst I have been near a 767 many times, I only have a Radio "ticket", not a full Avionics licence. On this point, the pilot probably had as much authority to clear the aircraft for flight as I did ;-)I'm having difficulty figuring out what the reports are talking about (basically it's all rumours and innuendo at the moment). It may not have been a light as such, but an EICAS msg(?). I don't know about the 757, but on the 767, there are a number of EICAS Status and Advisory msgs related to the Air-Ground system (if that is what the problem was). It may have seemed like a minor "indication" problem to an unqualified person, but a can of worms with serious consequences to a person with more knowledge on the subject.On 767's and similar aircraft, the Air-Ground System basically runs the entire aircraft :-) It has inputs to probably up to 100 aircraft systems/subsystems. That is not to say that the (mentioned on some sites) nose gear part of the Air-Ground system inputs into all of these. There may only be a few systems affected by the nose gear "proximity sensors". Irrespective, in my 767 Maintenance Manual, I don't see "taxying at high speed and braking hard to shift cargo" listed as a remedy for Air-Ground sensing problems :-) Who is to say that there wasn't a serious W&B problem causing the nose to rise in the air, making the aircraft think it was taking off? Just looking at the air-ground target/sensor setup on the nosegear of a 767 (and assuming the 757 is the same) you would have to wonder just how tail-heavy it would have had to have been to generate particular air-ground EICAS messages (especially the "AIR/GND SYS" EICAS Advisory message on later 767's).On each gear, there is a duplicate air-ground sensing system (for redundancy). In the pic below, I've marked one of the nose gear air-ground sensors (and associated target):http://members.ozemail.com.au/~b744er/767/...ProxSwitch1.jpgIf the lower half of the strut extends (as it does on takeoff), the shiny chrome bit gets longer and the linkages aft of the strut position themselves so that the target moves towards the sensor. From memory, the target has to be pretty close to the sensor before anything happens (i.e. lots of extension). If the nose gear strut really was extended to a great degree, you may even have problems controlling the steering of the aircraft on takeoff. If the strut extension was due to W&B, you would also have to worry about tailstrike and controllability in the air.The consequences of having the aircraft think it is in the air when it is not... and vice versa... vary depending on the system. Having a reverser deploy in the air (a-la-Lauda) may be far worse than having a reverser not deploy on the ground. Having a fault with the air-ground system may combine with other faults to cause even greater problems (e.g. Cargo doors unlatching and being torn off, causing death and injury... a-la-United).Anyway, that's all the speculation I'm going to do today... other than speculate on how much pressure the pilot was under to get the aircaft back home (or to the nearest airport where proper maintenance could have been carried out). Probably lots. Whether it was due to costcutting or something else, I can't say, but I wouldn't have liked to have been in his/her shoes.My 2c's worth.Cheers.Ian.P.S. Something I would have liked to have know was how much braking did the pilot do? Was there any danger of overheating the tyres/brakes? Was there sufficient cooling time allowed between aborted takeoffs?