markboston
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A380 Electrical Harnesses

Sat Jun 17, 2006 2:37 am

I have been reading that installation of "electrical harnesses" is delaying production of the A380.

Can someone explain what an electrical harness is?

Is this problem considered to be a manufacturing/assembly problem or a design problem?
 
aogdesk
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RE: A380 Electrical Harnesses

Sat Jun 17, 2006 2:53 am

I'm sure a knowledgeable someone will jump in soon with a detailed description of the situation facing the 380, but I can tell you that wiring harnesses are simply bundles of wires that have to be routed throughout the airframe and engine to handle the electric and electronic loads of systems and components. I believe I read that the 380 has about 200 MILES of wiring, hence difficulties....
 
AvionicMech
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RE: A380 Electrical Harnesses

Sat Jun 17, 2006 7:42 am

I have spoken to a few people who have worked as contractors on the A380 and they have mentioned that they had lots of problems with wiring turning up from suppliers with very bad connections on the crimped on them.

Also they have said that some of the people working there have no aircraft experience and have no idea about aircraft wiring. For example they had one person who put a red pin into a blue hole of a plug and therefore as soon as it was connected the pin pushed out etc etc.
 
474218
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RE: A380 Electrical Harnesses

Sat Jun 17, 2006 8:01 am

Quoting Markboston (Thread starter):
Can someone explain what an electrical harness is?

Look under the hood (bonnet) of your car. See the wires that are all taped together running all over the place. Those are wire harnesses. Now, assume a car that is 250 feet long and 20 feet wide and you may understand why they are having trouble getting everything sorted out.
 
fr8mech
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RE: A380 Electrical Harnesses

Sat Jun 17, 2006 9:32 am

There isn't just one wire harness, there are hundreds, maybe thousands on an aircraft the size of the A380.

Harnesses look simply but can be incredibly complex. Some wire harnesses may be only a few wires or the may be made up of hundred of wires. Each wire must be labeled with its wire number and part number.

A single harness may have several other harnesses that branch off and form there own 'main' harness for that particular location.

On top of all the wiring and connectors each wire must be reflected in the wiring diagram/wire list. The wiring diagram will show the wires as connected in relation to other wires in the system. The wire list will have the wire, bundle number and its terminations.

Like I said, they can be rather complex.
When seconds count...the police are minutes away.
 
Bobster2
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RE: A380 Electrical Harnesses

Sat Jun 17, 2006 11:36 am

Why wasn't the problem known when they built the first A380's? It seems that the first few planes were assembled OK and then something went to heck after that.
"I tell you this, no eternal reward will forgive us now for wasting the dawn." Jim Morrison
 
fr8mech
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RE: A380 Electrical Harnesses

Sat Jun 17, 2006 10:11 pm

We don't KNOW that they were OK. We know that the aircraft flew and went through testing. We don't know anything about the gripes that were developed during the flights.

Now, let's take the leap: if the problems with the systems were known, and were substantial, but under reported by Airbus; what is their responsibility or liability to their customers and shareholders?

At what point should Airbus report problems with the test aircraft? Remember, a wire harness problem does not necessarily mean a chapter 24 (electrical) problem. Any chapter can be effected. How long and how may problems did it take to narrow it down to wiring through-out the aircraft, if that's the problem?
When seconds count...the police are minutes away.
 
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HAWK21M
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RE: A380 Electrical Harnesses

Sun Jun 18, 2006 12:02 am

A Collection/Bunch/Group of Electrical Wires.
regds
MEL
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esgg
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RE: A380 Electrical Harnesses

Sun Jun 18, 2006 12:37 am

I am working in the automotive industry an when designing a new model, the car is first built in an 3D-cad program. I.E. everything is mounted as it would be in the real word, except that it is made in a computer. That test reveals a lot of collisions between different structural elements and piping, cable harnesses etc. I suppose this is done also with a complex thing as an airplane. But remember that an airplane is far far more complex than a car.

On the other hand, a PTO (pre series try out) is often built manually and the problems solved as they appear. The final product that later will be built, has always a number of solutions that differ from the PTO.
It is a very common problem that the solution on a problem is clear, but the subcontractor that is delivering the actual component fails to meet the specifications. As earlier mentioned:

Quoting AvionicMech (Reply 2):
Also they have said that some of the people working there have no aircraft experience and have no idea about aircraft wiring.
 
fr8mech
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RE: A380 Electrical Harnesses

Sun Jun 18, 2006 1:56 am

Quoting AvionicMech (Reply 2):
Also they have said that some of the people working there have no aircraft experience and have no idea about aircraft wiring.

The people building up the harnesses don't have to know anything about aircraft. They have to know how to follow the specs and they have to know wiring. Mistakes coming out of a vendor are a QC/QA issue.
When seconds count...the police are minutes away.
 
Matt72033
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RE: A380 Electrical Harnesses

Sun Jun 18, 2006 5:00 am

Quoting Markboston (Thread starter):
I have been reading that installation of "electrical harnesses" is delaying production of the A380.

well i heard it wasnt so much the installing of the wires.....but the discovery of a few looms within the aircraft that have been cut.....possibly sabotaged!
 
3DPlanes
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RE: A380 Electrical Harnesses

Sun Jun 18, 2006 11:56 am

Quoting Matt72033 (Reply 10):
well i heard it wasnt so much the installing of the wires.....but the discovery of a few looms within the aircraft that have been cut.....possibly sabotaged!

But that wouldn't explain why they've had to delay their production ramp up so much... Instead of 24 planes next year, it's down to 9 (or numbers similar to those). A cut harness or two (or even a bunch) shouldn't cause that kind of an impact.

An interesting, though non-technical, theory I've read about involves dropping the stock prices in order to devalue the buy out of BAe. Then, once that's done, announce that a "fix" has been developed at Farnborough. Seems awfully risky though, especially given their apparent troubles with the A350. I am curious what kind of problem - just coming to light now, only a few months before the first delivery - would cause such a major impact on production numbers?

I'm guessing that some sort of problem was found, one possible fix (possibly only one) was started on, and now at a very late stage found not to work, with no alternative solution...

-3DPlanes
"Simplicate and add lightness." - Ed Heinemann
 
Matt72033
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RE: A380 Electrical Harnesses

Sun Jun 18, 2006 3:53 pm

Quoting 3DPlanes (Reply 11):
A cut harness or two (or even a bunch) shouldn't cause that kind of an impact.

unless it proved a lot of test data un-useable now? i dont know, i was just saying what i heard!
 
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HAWK21M
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RE: A380 Electrical Harnesses

Mon Jun 19, 2006 2:13 am

Quoting ESGG (Reply 8):
. I suppose this is done also with a complex thing as an airplane.

Remember the B777.

Quoting Matt72033 (Reply 10):
.....but the discovery of a few looms within the aircraft that have been cut.....possibly sabotaged!

That if true is a very serious Occurance.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
northseatiger
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RE: A380 Electrical Harnesses

Mon Jun 19, 2006 7:07 pm

Quoting Fr8Mech (Reply 9):
The people building up the harnesses don't have to know anything about aircraft. They have to know how to follow the specs and they have to know wiring. Mistakes coming out of a vendor are a QC/QA issue.

True if they are at a company physically making the wiring, but if they are at the factory installing the looms to the aircraft then they should have experience or this is where problems can occur, incorrect routing, incorrect attatchment i.e tye-wrapping on to the wrong piece of a/c. Seen it before.
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manzoori
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RE: A380 Electrical Harnesses

Mon Jun 19, 2006 11:17 pm

An interesting item I read elsewhere (can't remember where but probably the Civ Av forum) speculated the wiring changes were down to a switch from Copper to Aluminium wiring. This will potentially save a tonne in weight but in order to keep the same resistance levels the Aluminium wiring has to go up several gauges.

Consequently where the wiring passes through bulkheads etc the existing holes are no longer big enough to accomodate the bigger (but lighter) wiring and that's where the changes are coming from.

To further add to the speculation, I've also read that this has been announced now to drive down EADS shares and reduce the payout to BAE Systems. Once they've been bought out, a miracle fix is rolled out recovering leadtimes... again, pure speculation!  Wink

Cheers!

Rez
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MechEngineer
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RE: A380 Electrical Harnesses

Mon Jun 19, 2006 11:51 pm

As far as I am informed from Hamburg, the delay with the A380 wiring isn't because of the basic aircraft systems, but the optional cabin interior equipment (IFE and seat controls in First and business class, for example).

Seems that all those airlines that are paying tons of money for their kingsize airliner want their very own special systems design in the cabin, and Airbus are simply swamped with work because of it.
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aogdesk
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RE: A380 Electrical Harnesses

Tue Jun 20, 2006 12:36 am

I've heard of the same issue with other systems such as certain airlines wanting to have 02 delivered to EVERY seat, a feature that was not in the original plans.
 
kaddyuk
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RE: A380 Electrical Harnesses

Tue Jun 20, 2006 6:52 am

Quoting Aogdesk (Reply 17):
such as certain airlines wanting to have 02 delivered to EVERY seat, a feature that was not in the original plans.

Oxy Generators do a better job with less weight penalties & complications...  Smile
Whoever said "laughter is the best medicine" never had Gonorrhea
 
nitrohelper
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 3:24 am

Good day to all, it is now 3 + months since the last tech talk about what really doesn't fit, or "line-up" with the Harnesses. Are there any of you Busguys around here that know what the current best story is on the WhaleJet and it's problem with "sparks & smoke"? flamed 
What is the fix and why a year to repair? Is it design, production,or vendors?
I guess the 350XYZ rev.06 will have a new CAD supplier and operators as "lessons" learned. scratchchin 

Quoting MechEngineer (Reply 16):
As far as I am informed from Hamburg, the delay with the A380 wiring isn't because of the basic aircraft systems,
 
MrChips
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 4:35 am

Quoting Manzoori (Reply 15):
An interesting item I read elsewhere (can't remember where but probably the Civ Av forum) speculated the wiring changes were down to a switch from Copper to Aluminium wiring. This will potentially save a tonne in weight but in order to keep the same resistance levels the Aluminium wiring has to go up several gauges.

Consequently where the wiring passes through bulkheads etc the existing holes are no longer big enough to accomodate the bigger (but lighter) wiring and that's where the changes are coming from.

This is the generally accepted theory as to the cause of the wiring problem. The reason for the huge production delays is twofold:

1) All the places where the wiring harness passes through bulkheads, panels, etc. need to be larger to accomodate the larger wires. This means there is considerable engineering work on any part of the strucutre that the wiring passes through, as making larger holes in anything will compromise the strength of the original design.

2) There will need to be considerable testing done on the EMF emission characteristics of the new wiring harness. I would imagine that Airbus has an "iron bird" for the A380, and no doubt the new wiring is already well on its way through the testing program.
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Dougloid
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 4:55 am

The main bundle in the MD11 is about as big around as your thigh. I'm guessing the A380 bundle is the size of Roseann Barr's thighs-pre mod, of course.

I think the problem's more fundamental than won't fit-it's a "no damned way" situation.

Which explains that the prototype has got wire running every which way scabbed on to keep it flying.
What they've decided to do, as near as i can figure out, is stop the line, rip out everything, and start from scratch. They've got hulls built and stacking up in the factory.

And if this means ripping out a lot and starting from scratch, there's going to be structure involved which explains the time delay. Reworking pass throughs in floor beams, anyone?

Ask any fool who ever used aluminum wire in a residential wiring job what he thought of it ten years later....
If you believe in coincidence, you haven't looked close enough-Joe Leaphorn
 
LMP737
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 8:14 am

Quoting Dougloid (Reply 21):
Ask any fool who ever used aluminum wire in a residential wiring job what he thought of it ten years later

This is slighty off topic but I know that during the 70's a lot of homes in Orange County, Ca were built using aluminum wiring. And around a hundred house fires were atributed to it.
Never take financial advice from co-workers.
 
nitrohelper
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 8:43 am

I'm sure the floor beams didn't have any extra space,or thickness to play with!
Thanks for the update, big big headaches for sure, hope a year will get it.
I've had similar space problems with building Hospitals, but they didn't have to fly when we were done!
 
777236ER
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 9:56 am

This is nothing more (or less) than an engineering fuck up.

If Airbus are switching from Cu to Al wiring, then you really have to question the logic. Whilst this may save considerable weight, is the A380 so far above weight targets that it's justified to delay the programme for a year (incuring massive costs and huge penalties) just to save a few tonnes?

I really can't believe Airbus went into any sort of serious production with weight problems hanging over them, and I really don't think they underestimated the size of harnesses, so what's actually going on here?

This is another pointer to me that Airbus developed the A380 slightly too soon. As it is, they're bringing out an aircraft with lots of GLARE and Al-Li, but limited use of carbon composites, engines that have SFC values and MX costs comparable to 777 engines, but not 787 engines, and they're stuck using technology that will be out of date when the first A380 is delivered.

Why didn't Airbus use ethernet on the A380? The technology was pretty mature even in the mid-90s, it would have saved a lot of weight and prevented these problems. It's not like Airbus to shy away from avionics technology, so why wasn't that route pursued?
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Dougloid
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 12:45 pm

Quoting 777236ER (Reply 24):
This is nothing more (or less) than an engineering fuck up.

Not only is it an engineering fuckup, but it is a bottled in bond, 100 proof deluxe fuckup with all the trimmings, cast of thousands, worthy of Cecil B. DeMille and suitable for Her Majesty in Buckingham Palace no less.

But there is something fundamentally wrong with the picture that I haven't entirly figured out yet.

It bespeaks a total lack of communication between the factory floor and the engineering department, because if they were talking to each other the problem never would have gotten this far. It would have been detected two or three years ago and cured.

The flopping sound you hear in Toulouse is W. Edwards Deming rolling over in his grave at about 700 rpm.

I can tell you with complete assurance this never would have happened at Douglas. Engineering was there shipside with the authority to cut EOs and make whatever changes were necessary to proceed, and we as QA and production had direct access to all levels of engineering by picking up the phone. Plus, our engineering was there on site in Long Beach. We could always find them in the Ivory Tower.

See, nobody there from the production side ever lost sight of the fact that we were in the business of making airplanes and if we didn't make them we'd all be out of jobs. I may criticize their goofy management but this was one they would have caught early on and fixed it.
If you believe in coincidence, you haven't looked close enough-Joe Leaphorn
 
sonic67
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 2:16 pm

Quoting Bobster2 (Reply 5):
Why wasn't the problem known when they built the first A380's? It seems that the first few planes were assembled OK and then something went to heck after that.

The first few A380 to take flight didn't have a full interior plus all the wiring to go with it. Airbus decide to switch to Aluminium wiring to solve some of the weight issues but by doing this they caused them self some major headaches and delays to go with it.
 
saintsman
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 3:51 pm

I once worked on a new wing design. To save money they only designed one wing, the theory being that the other wing was built opposite hand. (this is a common way of designing things). However, the designers did not realise that they couldn't design the electrics the same way because although the mechanical structures could be manufactured left and right hand, the components installed to the wing weren't handed.

So for example, if a component had a plug connector on its left hand side it would still be on the left hand side when fitted to the other wing. They had designed the wiring to fit on the left hand side but on the other wing it was designed to fit the right hand side (opposite hand).

Designers are clever people but sometimes they miss the bleedin' obvious!!
 
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Starlionblue
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 8:34 pm

Quoting Dougloid (Reply 25):

The flopping sound you hear in Toulouse is W. Edwards Deming rolling over in his grave at about 700 rpm.

This reminds me of the Dilbert cartoon: "Our new plan is to extract electrical power from the spinning corpse of our former CEO as he senses our current business practices."
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Pihero
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 8:57 pm

Quoting Dougloid (Reply 25):
I can tell you with complete assurance this never would have happened at Douglas. Engineering was there shipside with the authority to cut EOs and make whatever changes were necessary to proceed, and we as QA and production had direct access to all levels of engineering by picking up the phone. Plus, our engineering was there on site in Long Beach. We could always find them in the Ivory Tower.

Never happened at Douglas....?
Yet they built airplanes with doors carrying a major design defect,
hydraulic systems that were backward and without any plug protection., control cable routing that were vulnerable under weak cabin floor...Really impressive engineering !

[Edited 2006-10-12 14:04:34]

[Edited 2006-10-12 14:06:11]
Contrail designer
 
Pihero
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 9:00 pm

Quoting Dougloid (Reply 25):
Not only is it an engineering fuckup, but it is a bottled in bond, 100 proof deluxe fuckup with all the trimmings, cast of thousands, worthy of Cecil B. DeMille and suitable for Her Majesty in Buckingham Palace no less.

And you conveniently forget that an MD 11 was lost to a fire caused by Douglas approved electrical harnesses for the IFE.
A bit of restraint seems to be in order from your side, Douggie !
Contrail designer
 
Dougloid
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 10:54 pm

Quoting Pihero (Reply 29):
Never happened at Douglas....?
Yet they built airplanes with doors carrying a major design defect,
hydraulic systems that were backward and without any plug protection., control cable routing that were vulnerable under weak cabin floor...Really impressive engineering !

the point i was trying to make is that this sourt of a production engineering fuckup wouldn't have happened there because the engineering, QA and production people worked well together-something that is not happening at Airbus these days for reasons that are unknown.

I figured someone would drag out and dust off every old skeleton from the last forty years and I'm not going to plow old ground-the subject's much too complicated. But:

The major design defect in the door was building a door that could be buggered shut by an illiterate cargo handler.

The hydraulic systems you talk of whould never have been an issue if: AA hadn't buggered the engine mount on the one they augered in in Chi-town and Wyman Gordon, General Electric, and the UAL maintenance people did not ignore a flaw in the fan disk forging that led to its ultimate failure and the total destruction of everything in the tail of the DC10 that crashed in Sioux City. It is problematic whether either aircraft would have survived in any event.

As to Swissair 111 a/k/a 448 (which I worked on quite a bit as it was the second MD11 built) the problem's much too complex to dispense with a one liner such as you toss around (and a lot different than you seem to imply) but in the interests of accuracy here are the conclusions Transport Canada drew. I'm not even sure where and when the IFE system was installed either.

It seems that the fire started in the cockpit and the crew had no integrated fire fighting plan or training. That's right, the investigation concluded that the crew had no plan to locate and fight a fire.

Findings as to Causes and Contributing Factors
Aircraft certification standards for material flammability were inadequate in that they allowed the use of materials that could be ignited and sustain or propagate fire. Consequently, flammable material propagated a fire that started above the ceiling on the right side of the cockpit near the cockpit rear wall. The fire spread and intensified rapidly to the extent that it degraded aircraft systems and the cockpit environment, and ultimately led to the loss of control of the aircraft.


Metallized polyethylene terephthalate (MPET)–type cover material on the thermal acoustic insulation blankets used in the aircraft was flammable. The cover material was most likely the first material to ignite, and constituted the largest portion of the combustible materials that contributed to the propagation and intensity of the fire.


Once ignited, other types of thermal acoustic insulation cover materials exhibit flame propagation characteristics similar to MPET-covered insulation blankets and do not meet the proposed revised flammability test criteria. Metallized polyvinyl fluoride–type cover material was installed in HB-IWF and was involved in the in-flight fire.


Silicone elastomeric end caps, hook-and-loop fasteners, foams, adhesives, and thermal acoustic insulation splicing tapes contributed to the propagation and intensity of the fire.


The type of circuit breakers (CB) used in the aircraft were similar to those in general aircraft use, and were not capable of protecting against all types of wire arcing events. The fire most likely started from a wire arcing event.


A segment of in-flight entertainment network (IFEN) power supply unit cable (1-3791) exhibited a region of resolidified copper on one wire that was caused by an arcing event. This resolidified copper was determined to be located near manufacturing station 383, in the area where the fire most likely originated. This arc was likely associated with the fire initiation event; however, it could not be determined whether this arced wire was the lead event.


There were no built-in smoke and fire detection and suppression devices in the area where the fire started and propagated, nor were they required by regulation. The lack of such devices delayed the identification of the existence of the fire, and allowed the fire to propagate unchecked until it became uncontrollable.


There was a reliance on sight and smell to detect and differentiate between odour or smoke from different potential sources. This reliance resulted in the misidentification of the initial odour and smoke as originating from an air conditioning source.


There was no integrated in-flight firefighting plan in place for the accident aircraft, nor was such a plan required by regulation. Therefore, the aircraft crew did not have procedures or training directing them to aggressively attempt to locate and eliminate the source of the smoke, and to expedite their preparations for a possible emergency landing. In the absence of such a firefighting plan, they concentrated on preparing the aircraft for the diversion and landing.


There is no requirement that a fire-induced failure be considered when completing the system safety analysis required for certification. The fire-related failure of silicone elastomeric end caps installed on air conditioning ducts resulted in the addition of a continuous supply of conditioned air that contributed to the propagation and intensity of the fire.


The loss of primary flight displays and lack of outside visual references forced the pilots to be reliant on the standby instruments for at least some portion of the last minutes of the flight. In the deteriorating cockpit environment, the positioning and small size of these instruments would have made it difficult for the pilots to transition to their use, and to continue to maintain the proper spatial orientation of the aircraft.
If you believe in coincidence, you haven't looked close enough-Joe Leaphorn
 
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zeke
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 11:10 pm

Quoting 777236ER (Reply 24):
Why didn't Airbus use ethernet on the A380? The technology was pretty mature even in the mid-90s, it would have saved a lot of weight and prevented these problems. It's not like Airbus to shy away from avionics technology, so why wasn't that route pursued?

Airbus has used a more advanced version of ethernet called ADFX (Avionics Full Duplex Switched Ethernet) on the 380 along with fibre optic data distribution system for the IFE. Its not the same as normal ethernet, it is fully duplex.

The aircraft has five ADFX domains. A hardware based firewall prevents access from the cabin domain to the avionics domains (which include the flight control, cockpit, fuel and LG and energy domains). All domains feature software based firewalls. Data from the avionics domain is fed to into the cabin domain for your moving map outside air temperature etc.

The IFE domain uses Gigabit-Ethernet to every seat with a storage capacity of 6 TByte with PowerPC-CPUs running each seat. The passenger cabin also has wireless networking in the cabin using leaky coax running through the cabin, with holes above each seat

Power supply is running on 115V AC, with a variable frequency from 400 to 800 Hz. The amount of power being consumed for avionics is 16 kW, galley 240 kW, IFE 60 kW and cabin lights 15 kW (a lot considering the reading lights are LEDs). Passenger seats come with a universal 100 W power supply (110 VAC) and universal socket.

The 747 was a great achievement in its day, however the demands of passengers these days is they want all the bells and whistles of modern IFE, which includes a heap of electronics. From what I understand Airbus could roll out 380s with current 747/777 standard of interiors (which is reasonably "dumb" and dated, i.e. bit like trying to keep a kid entertained by providing a book when they want an xbox and 200 channels of tv), but customers want the new gear as the aircraft is not only providing more space, it is value adding to a passengers journey.

Airbus has stuffed up big time, from what it looks like not having standardised/compatable versions of CAD across their design and manufacturing centers. From what I understand, they have all the pieces of the puzzle, they just got to get the instructions on how to put it all together.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
LMP737
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RE: A380 Electrical Harnesses

Thu Oct 12, 2006 11:26 pm

Quoting Pihero (Reply 30):
And you conveniently forget that an MD 11 was lost to a fire caused by Douglas approved electrical harnesses for the IFE.

< http://www.swissair111.org/sbaReport.pdf >
Never take financial advice from co-workers.
 
777236ER
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 3:02 am

Quoting Zeke (Reply 32):
The 747 was a great achievement in its day, however the demands of passengers these days is they want all the bells and whistles of modern IFE, which includes a heap of electronics. From what I understand Airbus could roll out 380s with current 747/777 standard of interiors (which is reasonably "dumb" and dated, i.e. bit like trying to keep a kid entertained by providing a book when they want an xbox and 200 channels of tv), but customers want the new gear as the aircraft is not only providing more space, it is value adding to a passengers journey.

I find this hard to believe.

Are Airbus sacrificing more than a year of production time, and spending millions (billions?) of Euros appeasing pissed off customers, harming other (more important) Airbus programmes and destroying all hopes of A380 profittability in the next decade, simply because customers want more fancy IFE? I doubt that very much.

Airlines can quite happily install on-demand IFE, including phones and large screens, on 747-400 aircraft - and aircraft that wasn't designed for it. Why should it take so long to make the A380 IFE-ready?

Airbus dropped a big bollock on this one. It's not as simple as 'customers want IFE'.
Your bone's got a little machine
 
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Starlionblue
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 3:23 am

Quoting 777236ER (Reply 34):

Airbus dropped a big bollock on this one. It's not as simple as 'customers want IFE'.

Sounds more like "customers want IFE" and Airbus screwed up the implementation.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
KELPkid
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 3:24 am

Quoting Zeke (Reply 32):
Its not the same as normal ethernet, it is fully duplex.

With all due respect, normal ethernet in the year 2006 (the twisted-pair variety, anyways-there is also several fiber optic versions which are also full-duplex) comes in two common flavors: 100 Mbps, full duplex and 1000 Mbps full duplex. The kicker is that both of these specifications have cable runs limited to 100 meters...this is where you could easily run into trouble in a large aircraft.

Half-duplex (what we call in the Information Technology wold "collision-domain") has pretty much gone the way of the dodo bird. If I see a hub anywhere on my network, it's history, because I can buy a consumer-level switch for not much money to take it's place  Smile (as well as much-improved data throughput!)

You probably would not want to use standard Cat 5 cabling for your installation if you were doing 100 Mbps-you would have two unused wiring pairs that the aircraft would be unnecessarily carrying around.

Also, ethernet is designed for a more centralized network topology: it works the best when the server is located at a central point (i.e. nice fast switch), with individual cable runs to each client (not that there aren't other network topologies that can be used with Ethernet  Wink ). Any place you don't have individual cable runs, you are sharing bandwidth, which is especially detrimental to streaming video and audio (such as an IFE system would be using...). The cabling to accomplish this (an individual wire to every seat) would be pretty high.
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
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Starlionblue
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 3:28 am

Quoting KELPkid (Reply 36):
If I see a hub anywhere on my network, it's history, because I can buy a consumer-level switch for not much money to take it's place Smile (as well as much-improved data throughput!)

Ironically the switch will probably be cheaper. Same with Access Points and Wireless Routers. The Router includes the AP and is still cheaper.

Long live the market  Wink
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Lemurs
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 3:30 am

Quoting 777236ER (Reply 34):
Airlines can quite happily install on-demand IFE, including phones and large screens, on 747-400 aircraft - and aircraft that wasn't designed for it. Why should it take so long to make the A380 IFE-ready?

The 747 is an entirely different creature though. It is still an previous generation, fly-by-cables airplane. The avionics required for normal operation of the airplane are much less complex, the signaling on the electronics/sensors that ARE there are much simpler, the IFE installations are not the same generation as the A380...it is just a different creature. You can't compare the two and say: "Since one works, it's obvious the other should work as well, just as easily." It's a logical fallicy.

You can be sure Boeing is sweating the details on the 787 wiring right now like nobody's business to make sure this doesn't happen to them. I guarantee you there is no one responsible for that part of the project right now thinking: "Well this is a much smaller airplane than the 747, so it will obviously be easier to manage. Ignore the fact that we'll be routing around half a megawatt of power while providing powered window shades, AVOD, wireless, etc..."
There are 10 kinds of people in the world; those who understand binary, and those that don't.
 
Lemurs
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 3:42 am

ADFX is a little more complex than just Full Duplex Ethernet. It has to be, because of the application. Ethernet is less than ideal for any kind of mission critical time-sensitive application because you don't have deterministic timing. If I am not mistaken, part of the ADFX standard is building in failover redundancy (required redundant switches and cables) as well as protocol extensions to allow for deterministic timing. So it lets them use off-the-shelf technology with "software" extensions to get the performance the application requires...without compromising the hard-limit timing needs of an airplane. It's a fantastic idea really.

Realtime computing is very demanding in a highly specific way...it's the biggest reason you don't really see crossover in the OS markets for such things. Windows Embedded or Linux can do these jobs, but they can't guarantee absolute behavior based on timings like WindRiver does...and WindRiver is so centered on being realtime responsive, it would make a terrible general purpose OS. This is why WindRiver dominates most airplane and manufacturing computers, behind the scenes.
There are 10 kinds of people in the world; those who understand binary, and those that don't.
 
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Starlionblue
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 5:12 am

Quoting Lemurs (Reply 39):
Realtime computing is very demanding in a highly specific way...it's the biggest reason you don't really see crossover in the OS markets for such things. Windows Embedded or Linux can do these jobs, but they can't guarantee absolute behavior based on timings like WindRiver does...and WindRiver is so centered on being realtime responsive, it would make a terrible general purpose OS. This is why WindRiver dominates most airplane and manufacturing computers, behind the scenes.

The Windows and Linux schedulers are pretty much round robin with some priorities. However, neither operating system has a built in scheduler that allows the dynamic setting of priorities. Sure, you can use "nice" in Linux or change priorities in the Windows Task Manager, but those are static solutions.

Third party solutions such as Aurema's ARMTech can add such capabilities to Windows and Linux, allowing guaranteed CPU allocations for defined processes/users/etc.. when those allocations are needed. However while this may "fix" the CPU issue, there is still no guarantee that other components in the system will respond in a predictable fashion. So you may have the instructions ready but the hard drive is busy.

"Enterprise class" operating systems such as zOS, AIX, Solaris, HP/UX have these capabilities built in as a matter of course. Incidentally, many such embedded capabilities, such as the Solaris Resource Manager, were also written by Aurema.

Flight Management Computers are built with every process having its own virtual OS. Thus the process is isolated from other faults and performance is predictable and "guaranteed".
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
WingedMigrator
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 10:55 am

Quoting MrChips (Reply 20):
This is the generally accepted theory as to the cause of the wiring problem.

I haven't seen any real evidence of aluminum wiring being at the root of the problem. That decision was made before production got very far. From reporting in Flight International, it seems it was mostly a configuration management disaster.

Quoting 777236ER (Reply 24):
As it is, they're bringing out an aircraft with lots of GLARE and Al-Li, but limited use of carbon composites, engines that have SFC values and MX costs comparable to 777 engines, but not 787 engines, and they're stuck using technology that will be out of date when the first A380 is delivered.

You might be interested to know that the A380 has 6 times more CFRP than it has GLARE (by mass) and that it contains more CFRP (again by mass) than a 787. Also, GE has said the SFC spread between the GEnx and the GP7200 is four percent.
 
nitrohelper
Posts: 406
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RE: A380 Electrical Harnesses

Fri Oct 13, 2006 10:26 pm

Quoting 777236ER (Reply 34):
Airlines can quite happily install on-demand IFE, including phones and large screens, on 747-400 aircraft -

I wasn't thinking about the 747 when trying to picture the harnesses and route paths on the 380, but now this raises more questions about the WhaleJet that can't swallow extra wires in its tummy!
Did the 747 have empty space designed for future systems, or did the Busfolks just
set a new record for FUBAR ?  blush  Yes , I know the two levels of seats, but this is new design with CAD "stuff" that engineers could only dream about in the 60's.
Are ropes&pulleys that much smaller than fly by wires?  scratchchin 
I still would like to hear from the busworkers just what they are doing to the existing Whalejets these days.  confused  Please no PR people need reply.
 
baroque
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RE: A380 Electrical Harnesses

Sat Oct 14, 2006 12:11 am

Quoting Dougloid (Reply 31):
The major design defect in the door was building a door that could be buggered shut by an illiterate cargo handler.

As I recall from reading Dest Disaster in 1977 (so forgive me if my memory has failed) but the design was assessed as faulty by Convair who had to build it because they knew of the potential problem. The memos pointing this out were suppressed because there was a contract negotiation coming up and Convair did not want to upset Douglas.

That could be relevant in the present case if some Airbus engineers did in fact spot the problem (whatever it is), but had their opinions suppressed. I have no idea whether this did or did not happen, but "modern" management does seem to be prone to shooting messengers. If that has been done, it might explain some of the delays while the suppressors got out from under their unhappy ways.

Quoting WingedMigrator (Reply 41):
You might be interested to know that the A380 has 6 times more CFRP than it has GLARE (by mass) and that it contains more CFRP (again by mass) than a 787. Also, GE has said the SFC spread between the GEnx and the GP7200 is four percent.

Hmm, nothing like a few figures to bring a bit of context into an argument. It also indicates why there may be no great rush to change to better Trents during the cooling off period, new ones might not be that much better.
 
Okie
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RE: A380 Electrical Harnesses

Sat Oct 14, 2006 1:13 am

Quoting Dougloid (Reply 25):
But there is something fundamentally wrong with the picture that I haven't entirly figured out yet.

It does not take a whole lot of mistakes early on in a design process to skew the end result. It does not matter if they are supplier related, engineering related, corporate culture related, ego related, QA related, just plain incompetence or all the above. In most cases problems tend to be multiplicative and not additive especially if introduced early on in the design process and not corrected.

Many issues that are listed here are possibilities, we may never know the total scope.

"Fundamentally", Airbus let this part of the project get way to far out of hand before assigning additional talent/resources to resolve issues with the problem.

I do not want to get into the A vs B deal here, as they both build fine aircraft. Somewhere along the line Airbus let this part of the project get away from them.

Okie
 
777236ER
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RE: A380 Electrical Harnesses

Sat Oct 14, 2006 2:56 am

Quoting WingedMigrator (Reply 41):

You might be interested to know that the A380 has 6 times more CFRP than it has GLARE (by mass) and that it contains more CFRP (again by mass) than a 787

Well, the major parts of the A380 which use CFRP and other thermosets are the horizontal stabiliser, rear pressure bulkhead, landing gear doors, some flood beams, wing ribs, the centre wing box, vertical stabiliser and unpressurised bits of the fuselage.

The 787, on the other hand, uses CFRP for wing skins and spars, the wing box, the entire fuselage and stabilisers.

The A380 is still a metal aircraft with composite bits, whereas the 787 is certainly a composite aircraft with metal bits.

It can be a bit misleading talking about composites in terms of mass, because they are just so light. The 787 is only 50% composite by mass, yet composites make up the vast bulk of the structure.
Your bone's got a little machine
 
WingedMigrator
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RE: A380 Electrical Harnesses

Sat Oct 14, 2006 11:55 am

Quoting Baroque (Reply 43):
Hmm, nothing like a few figures to bring a bit of context into an argument.

 Smile I forgot to toss in these harness-related figures that Streiff mentioned in a recent speech:

530 km of wiring
100,000 individual wires
40,300 connectors
 
nitrohelper
Posts: 406
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RE: A380 Electrical Harnesses

Sat Oct 14, 2006 9:58 pm

Quoting WingedMigrator (Reply 46):
40,300 connectors

After thinking about that number for a few minutes, mixed with alum.wires, and going through bulkheads on their way to terminations somewhere, I give alot of credit to the person at an Airbus meeting that said we have to Stop Now!
20/20 hindsight says they did the right thing, But the tapes from the Board meetings must be very good listening. I was the messenger of several "problems" to our nine member board, never got shot, but felt wounded a few times!
Anybody know if they are going to all copper wire ?
 
baroque
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RE: A380 Electrical Harnesses

Sun Oct 15, 2006 12:29 am

Quoting Nitrohelper (Reply 47):
I was the messenger of several "problems" to our nine member board, never got shot, but felt wounded a few times!

Dear Messenger

See if you can get a few Airbus members of your fraternity to tell us if there have been any casualties lately!!

Pegasus
 
dvautier
Posts: 56
Joined: Tue Oct 03, 2006 8:28 am

RE: A380 Electrical Harnesses

Wed Oct 18, 2006 4:34 am

Quoting WingedMigrator (Reply 46):
530 km of wiring
100,000 individual wires
40,300 connectors

How are you defining connection? A wire has two connections. If it goes through a bulkhead is it considered another wire on the circuit? If the circuit goes from A to B through non-pressurized or cargo areas then the wire type and separation may change. Are you considering that another wire or the same wire?

the information is confusing. Seems to me there are many more connections here? Or are they considered disconnects, or terminals, or terminations?
 smirk 

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