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Air Transat A330 Incident.  
User currently offlineMischadee From Sweden, joined Apr 2004, 271 posts, RR: 0
Posted (9 years 5 months 2 weeks 1 day 17 hours ago) and read 4455 times:

Hi all you fellow geeks Wink (That is what I'm called anyway)

Yesterday I saw a documentary about the Air Transat A330 that ran out of gas right in the middle of the Atlantic and had to glide to the Azores.

What puzzles me is that they said that they also lost all electrical systems. The only electric they could use was generated by a small wind driven propeller that was dropped from the bottom of the aircraft. I thought that the APU could generate electric when the engines weren't working? Or maybe that is only on the ground, I don't know? They also said that they had trouble slowing the aircraft down since they couldn't use the spoilers and the flaps. Is it supposed to work this way, it sounds crazy that you can't use spoilers or flaps when you lost all your engines?

Can someone clear this up for me. Was the information I got from the documentary correct?

Mischa.


ARNiboy
11 replies: All unread, jump to last
 
User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 1, posted (9 years 5 months 2 weeks 1 day 17 hours ago) and read 4444 times:

APU runs one fuel. No fuel = no APU.

The ram air turbine can only supply a certain amount of power, so only the most critical systems will be running. Flaps and spoilers probably don't belong in that category. Brakes, elevators, rudder and ailerons would be considered critical.

Staffan


User currently offlineOkie From United States of America, joined Jul 2003, 3047 posts, RR: 3
Reply 2, posted (9 years 5 months 2 weeks 1 day 17 hours ago) and read 4436 times:

Quoting Mischadee (Thread starter):



Quoting Mischadee (Thread starter):
The only electric they could use was generated by a small wind driven propeller that was dropped from the bottom of the aircraft.

Called Ram Air Turbine (RAT) Only provides emergency power for the aircraft not all systems are available. Some provide electric only, some provide hydraulic depending on the aircraft.

Quoting Mischadee (Thread starter):
I thought that the APU could generate electric when the engines weren't working? Or maybe that is only on the ground,

The APU gets its fuel from one of the main tanks and does not have a separate fuel tank. Also only some APU's can be started in flight depending on the design of the aircraft.

Quoting Mischadee (Thread starter):
They also said that they had trouble slowing the aircraft down since they couldn't use the spoilers and the flaps. Is it supposed to work this way, it sounds crazy that you can't use spoilers or flaps when you lost all your engines?

Only basic services are provided when operating with the RAT in emergency mode not many functions other that basic flying controls are available.

Okie


User currently offlineB747FE From Hong Kong, joined Jun 2004, 230 posts, RR: 4
Reply 3, posted (9 years 5 months 2 weeks 1 day 16 hours ago) and read 4415 times:

As far as I know, an engine out visual approach was carried out by Air Transat crew. Without Engine Driven Pumps, the Green Hydraulic System was powered by the Ram Air Turbine. In that configuration the Emergency Generator only provide 3.5 to 5.5 KVA, depending on the airspeed, and supplies only AC/DC essential buses and Essential TR.
Only spoiler surfaces # 1 and # 5 are available, and the priority is for the primary flight controls.
APU is in-flight certified, fed from engine # 2 collector box left inner tank, which I guess was empty.

Regards,
B747FE.



"Flying is more than a sport and more than a job; flying is pure passion and desire, which fill a lifetime"
User currently offlineFinningleyMech From United Kingdom, joined Sep 2004, 27 posts, RR: 0
Reply 4, posted (9 years 5 months 2 weeks 1 day 14 hours ago) and read 4344 times:

Hi there, I have the accident investigating report next to me right now, which I was given for human factors training.

The A330 had recently had an engine change in which an engine that had been modified was fitted in place of an un-modded engine. This resulted in incompatible parts being fitted to the new engine, i.e. parts from the older (in terms of updates/modifications) engine. Mainly a Fuel line which the Mx had to forcably bend to fit behind some hydraulic lines. The resulting contact and vibration of the two lines resulted in an 1 1/2 inch crack forming in the fuel line. When the aircraft started to loose fuel they crew referred to the aircrafts procedures handbook and decided it was a computer malfunction and transferred fuel from the engine that was not leaking to the engine that was leaking fuel. This resulted in both engines flaming out, basically running out of fuel. This meant that the Ram Air Turbine (RAT) was deployed to give a small amount of electrical power to run the aircrafts navigation instruments.

As you said the aircraft struggled to slow down as a no flaps landing was performed. The overspeed landing resulted in major damage to the main gear of the aircraft.

You ma be interested to know that earlier in the flight, the crew were directed to divert from their flight plan slightly by ATC slightly due to busy ATC in another area. If the Aircraft had not diverted then it would be very likely that an over water ditching would have had to take place, and the likelihood of survivors being very low indeed.

As I said I have the report here if you have any other questions.

Hope this helps.
Kieron



Unofficial A.net Finningley Rep
User currently offlineMischadee From Sweden, joined Apr 2004, 271 posts, RR: 0
Reply 5, posted (9 years 5 months 2 weeks 1 day 13 hours ago) and read 4313 times:

Thanks for the answers guys.

I must say that even though the pilots came out as heroes for being able to glide land the plane in my opinion they made some serious mistakes. In my point of view it seemed like they just ignored the computer warnings, I mean the computers are there for a reason.

Mischa.



ARNiboy
User currently offline777WT From United States of America, joined Jan 2005, 877 posts, RR: 1
Reply 6, posted (9 years 5 months 2 weeks 1 day 13 hours ago) and read 4305 times:

Quoting FinningleyMech (Reply 4):
Hi there, I have the accident investigating report next to me right now, which I was given for human factors training.

The A330 had recently had an engine change in which an engine that had been modified was fitted in place of an un-modded engine. This resulted in incompatible parts being fitted to the new engine, i.e. parts from the older (in terms of updates/modifications) engine. Mainly a Fuel line which the Mx had to forcably bend to fit behind some hydraulic lines. The resulting contact and vibration of the two lines resulted in an 1 1/2 inch crack forming in the fuel line. When the aircraft started to loose fuel they crew referred to the aircrafts procedures handbook and decided it was a computer malfunction and transferred fuel from the engine that was not leaking to the engine that was leaking fuel. This resulted in both engines flaming out, basically running out of fuel. This meant that the Ram Air Turbine (RAT) was deployed to give a small amount of electrical power to run the aircrafts navigation instruments.

As you said the aircraft struggled to slow down as a no flaps landing was performed. The overspeed landing resulted in major damage to the main gear of the aircraft.

You ma be interested to know that earlier in the flight, the crew were directed to divert from their flight plan slightly by ATC slightly due to busy ATC in another area. If the Aircraft had not diverted then it would be very likely that an over water ditching would have had to take place, and the likelihood of survivors being very low indeed.

As I said I have the report here if you have any other questions.

Hope this helps.
Kieron

Correct. I saw the video as well. At the end of the video, they mentioned the company report is confidential of what the pilots were talking about that flight and their actions and it said the report will not be released to the public. I would like to know what was in it and why.

All I know the pilots kept their job, put on probation and had to go for remedical in fuel management training.

That and the AA Flight 587 report (forgot the name but it started with a 'B') that the president of AA read and was shocked by it, they destroyed the report so it wouldn't fall into other hands.
Somehow another copy of the AA report surfaced and MD was in court with AA over the DC10, when MD brought up the issue of that report demanding it to be released, the supervisor mechanic of that DC10 committed sudicide by running his car in the garage inhaling carbon monoxide, then AA agreeded to a settlement with MD when MD let the AA report slide in favor of the settlement.


User currently offlineBuckFifty From Canada, joined Oct 2001, 1316 posts, RR: 20
Reply 7, posted (9 years 5 months 2 weeks 1 day 10 hours ago) and read 4206 times:

I must say that even though the pilots came out as heroes for being able to glide land the plane in my opinion they made some serious mistakes. In my point of view it seemed like they just ignored the computer warnings, I mean the computers are there for a reason.

The computers do lie sometimes. In fact, they do it quite frequently on the Airbus, spurious warnings happen all the time. However, it is the crew's job to interpret the multitude of information in their grasp, and develop a satisfactory response to the problem. It is here that the crew ultimately failed.

Yet there are no real warnings to how a leak occurs, the computers cannot locate leaks and warn the crew. All there is at hand is the multitude of fuel calculations one must partake as part of the cruise to ensure that everything is normal.

In our emergency procedures, it talks about 'suspected' leaks, not 'actual', and how to deal with them. Interpreting the information at hand is crucial. There is no warning that pops up and says 'ENGINE TWO LEAK'. Instead, the initial indications they had were an unusual oil level indication for the #2 engine, and a fuel imbalance advisory on the EW/D.

It all seems so easy afterward to assume the correct crew actions, and now that we know, it does make a difference for our future analysis for the same kind of incident. But at the time, the crew must have been under a lot of pressure to find the problem, and fly the aircraft at the same time. Should it have happened? It's easy to say of course not, though it really shouldn't have. I just feel that they haven't received the adequate training, which is also the fault of the company that employed them (not to mention the engineering blunder that started this whole ordeal.)


User currently offlineHAWK21M From India, joined Jan 2001, 31684 posts, RR: 56
Reply 8, posted (9 years 5 months 2 weeks 1 day ago) and read 4078 times:

Quoting 777WT (Reply 6):
they mentioned the company report is confidential of what the pilots were talking about that flight and their actions and it said the report will not be released to the public. I would like to know what was in it and why.

Was there any Official Investigation in to the same,what were their exact findings.Any Links.
regds
MEL



Think of the brighter side!
User currently offlineDAirbus From United States of America, joined Nov 2003, 593 posts, RR: 2
Reply 9, posted (9 years 5 months 2 weeks 20 hours ago) and read 4043 times:
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Here is a link to the official accident report by the Portugese authorities.

http://www.gpiaa-portugal-report.com/


There are some interesting automation and human factors issues that arise from this accident. I have added two excerpts from the report below. The first one gives an idea of the thought processes by the pilots:

The crew stated that because there were no other signs of a fuel loss, other than the lower than expected quantity of fuel on board, and because there had been no other ECAM warnings or cautions both pilots believed that the problem was a computer fault. They also stated that although they had used the term “fuel leak” on many occasions during the occurrence, a logical link to considering the FUEL LEAK check and the possibility that the fuel leak existed did not occur until the aircraft indicated fuel quantity was about 7 tons.

The crew stated that they continued to believe that the low quantity indications were caused by some type of computer error, and continued with this belief up to and beyond the flameout of the right engine.



The second excerpt deals with the human factors issue and the pitfalls of automation:

The FCMC in the A330 is based upon a management by exception philosophy; the operators are effectively relieved from the active tasks of managing fuel transfers, as all functions are handled by the FCMC. Only those messages considered important are communicated to the crew through the ECAM.

The A330 FCMC system was not designed to consider the type of fuel leak that occurred during this flight. As a result, after the FCMC did what it could do to maintain a fuel level of 4 tons in the right tank and when it was no longer able to maintain that level, it advised the crew that there was an imbalance. Specifically, the FCMC, no longer able to deal with the fuel leak through its pre-programmed fuel balancing, shed the task to the crew. This shedding took the form of a fuel imbalance ADV.

With Management by exception, it is not uncommon to have what have been referred to as “automation surprises”. Although information may be available to crews, this information is not necessarily observable. Observability, in this context, refers to the cognitive work that is required to extract useful information. It results from the interplay between a human user knowing when
to look for what information, at what point in time, and the structure of the automated system and how it supports attention guidance.

The challenge is for automation to not merely provide additional data but to reduce the cognitive effort required to locate, integrate, and interpret those data. For this occurrence, the low level of system observability was manifested in two ways:

• The sudden presentation of apparently anomalous and incredulous information; and

• A representation of the system state that does not readily lead the crew to identify and rectify the problem.



What I got after reading the accident report is that many pilots are trained to let the automation work and not to expect notification of every action that is taking place behind the scenes. Basically the idea is if you need to take some action, the aircraft will let you know. Since there was nothing flashing at the crew specifically saying "FUEL LEAK" with the accompaning warning lights, they had a difficult time finding out exactly what was going on until they had lost all their fuel. What is also interesting is that after the accident Airbus issued a service bulletin with instructions on how to modify the A330 Flight Warning Computer to display a warning message when the fuel used according to the FMC flight plan difers from the Fuel on Board by more than 3,500KG or 7,700 lbs. Such a warning would of alerted the AirTransat crew to the fuel leak earlier before all fuel was lost.



Regards

DAirbus



"I love mankind. It's people I can't stand." - Charles Shultz
User currently offlineAvionicMech From United Kingdom, joined Jan 2005, 315 posts, RR: 3
Reply 10, posted (9 years 5 months 2 weeks 16 hours ago) and read 3988 times:

Quoting BuckFifty (Reply 7):
There is no warning that pops up and says 'ENGINE TWO LEAK'

Well there is sort of, but not fuel its bleed air, ie. DUCT LEAK.  Wink


User currently offlineBio15 From Colombia, joined Mar 2001, 1089 posts, RR: 7
Reply 11, posted (9 years 5 months 2 weeks 15 hours ago) and read 4005 times:

Quoting BuckFifty (Reply 7):
The computers do lie sometimes. In fact, they do it quite frequently on the Airbus, spurious warnings happen all the time. However, it is the crew's job to interpret the multitude of information in their grasp, and develop a satisfactory response to the problem. It is here that the crew ultimately failed.

That doesn't sound right, computers lie frequently on the Airbus aircraft? I wouldn't think they lie frequently on any civilian transport aircraft at all. If this is happening, isn't there a serious issue to be dealt with?

Alfredo


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