Spanair accident at Madrid
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circuit breakers
The information came from a block diag and from post #2003, mermoz92,although they refer to the possibility that breakers feeding the RAT heater breaker may have been switched of as per maint man to ensure isolation.If these were not reset other functions would be unpowered including tows.
I must try to read your Graph thoroughly after assembling the tiles,to see if it is possible to establish if RL2-5 was faulty or if alternatively there is any evidence that the sensor logic feeding the relay was erroneously causing it to be de-energized.
Apologies to the winged fraternity for boring technicalities.
I must try to read your Graph thoroughly after assembling the tiles,to see if it is possible to establish if RL2-5 was faulty or if alternatively there is any evidence that the sensor logic feeding the relay was erroneously causing it to be de-energized.
Apologies to the winged fraternity for boring technicalities.
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For that and other reasons I do not believe at all it was for "commercial reasons" that some airlines (not only Spanair) "stuck" to the original McDonell recommendation of checking TOWS in the first flight of the day and then whenever pilots entered a "new" cockpit or where absent from an "old" one for a long time.
They know TOWS don't fail that often nor are they too hard or expensive to fix (relatively quite a simple system).
They know it SAVES them money. They know it only takes 2 seconds to test them.
But somewhere, the person translating/writing the SOPs for Spanair (and other airliners) never heard of Boeing LATER recommendations to change that to "check the TOWS before each and every takeoff-period".
Nor did the FAA or EASA or any other regulatory body in the world make such a recommendation mandatory.
I'm pretty sure should there have been better communication between Boeing and Spanair (or the other operators which SOPs still didn't include the updated procedure), I'm pretty sure it would've been adopted.
In fact, Spanair adopted it a few days after the accident, before any recommendations or directives were out.
I do not know what communication channel failed there. I don't know if it is each individual airline job to constantly bombard Boeing with:
-"Have you changed anything from our SOP"?
-"Have you changed anything from our SOP"?
-"Have you changed anything from our SOP"?
Or if it is Boeing's job to query each operator flying their airplanes:
-"Have you included recommendation update YYY-XXX?"
-"Have you included recommendation update XXX-YYZ?"
-"Have you included recommendation update AAA-BBB?"
Or if all Boeing has to do is fax EASA/FAA/each country's authority and say:
"Remember procedure XXX-XXX? Well, it was wrong. We found a better one. Please tell everybody to use YYY-ZZZZ instead. This is the only communication we will send out."
And then pass the ball to each country regulatory body to oversee the update and compliance.
Spanair claims they were never told about the update in procedure and therefore never included it. Their SOPs were the ones they thought were recommended by the manufacturer and approved by Spanish and European regulatory agencies and of course would've passed FAA ones too. Other airliners flying at the time in Europe used the same standard procedure.
So who do we "blame"? Obviously all of them have some "fault" in the subject, but who is the main culprit? The way it is now, it seems they all thought they were doing the right thing. Except, maybe, Aviación Civil or perhaps FAA/EASA?
They know TOWS don't fail that often nor are they too hard or expensive to fix (relatively quite a simple system).
They know it SAVES them money. They know it only takes 2 seconds to test them.
But somewhere, the person translating/writing the SOPs for Spanair (and other airliners) never heard of Boeing LATER recommendations to change that to "check the TOWS before each and every takeoff-period".
Nor did the FAA or EASA or any other regulatory body in the world make such a recommendation mandatory.
I'm pretty sure should there have been better communication between Boeing and Spanair (or the other operators which SOPs still didn't include the updated procedure), I'm pretty sure it would've been adopted.
In fact, Spanair adopted it a few days after the accident, before any recommendations or directives were out.
I do not know what communication channel failed there. I don't know if it is each individual airline job to constantly bombard Boeing with:
-"Have you changed anything from our SOP"?
-"Have you changed anything from our SOP"?
-"Have you changed anything from our SOP"?
Or if it is Boeing's job to query each operator flying their airplanes:
-"Have you included recommendation update YYY-XXX?"
-"Have you included recommendation update XXX-YYZ?"
-"Have you included recommendation update AAA-BBB?"
Or if all Boeing has to do is fax EASA/FAA/each country's authority and say:
"Remember procedure XXX-XXX? Well, it was wrong. We found a better one. Please tell everybody to use YYY-ZZZZ instead. This is the only communication we will send out."
And then pass the ball to each country regulatory body to oversee the update and compliance.
Spanair claims they were never told about the update in procedure and therefore never included it. Their SOPs were the ones they thought were recommended by the manufacturer and approved by Spanish and European regulatory agencies and of course would've passed FAA ones too. Other airliners flying at the time in Europe used the same standard procedure.
So who do we "blame"? Obviously all of them have some "fault" in the subject, but who is the main culprit? The way it is now, it seems they all thought they were doing the right thing. Except, maybe, Aviación Civil or perhaps FAA/EASA?
Last edited by justme69; 10th Nov 2008 at 20:50.
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Oh, no, I understand the recommendation.
I also know the first one was made AFTER the accident in Detroit, and it was not the original, approved procedure.
I also know that many operators claim they NEVER WERE NOTIFIED of the recommendation. Plenty of them flying around up until very recently. As you very well say, for over 20 years since it was made.
I know Boeing CLAIMS they notified it to all operators that AT THAT TIME were using MD-80's. I also know that Spanair (and others) didn't exist at that time and started their operations AFTER the recommendation was sent out.
I'm also curious if Boeing recommended individual types, or better yet, ALL their planes, not only those with a generic "similar TOWS design" referring to the MD-80 series (other types have suffered similar accidents/incidents).
I wanted to know how it was possible that Spanair "inherited" an approved SOP that didn't include it and, apparently, nobody told them.
And why this recommendation wasn't "approved" and mandated by the FAA or ANY similar international bodies at all.
Until a week ago.
I also know the first one was made AFTER the accident in Detroit, and it was not the original, approved procedure.
I also know that many operators claim they NEVER WERE NOTIFIED of the recommendation. Plenty of them flying around up until very recently. As you very well say, for over 20 years since it was made.
I know Boeing CLAIMS they notified it to all operators that AT THAT TIME were using MD-80's. I also know that Spanair (and others) didn't exist at that time and started their operations AFTER the recommendation was sent out.
I'm also curious if Boeing recommended individual types, or better yet, ALL their planes, not only those with a generic "similar TOWS design" referring to the MD-80 series (other types have suffered similar accidents/incidents).
I wanted to know how it was possible that Spanair "inherited" an approved SOP that didn't include it and, apparently, nobody told them.
And why this recommendation wasn't "approved" and mandated by the FAA or ANY similar international bodies at all.
Until a week ago.
Last edited by justme69; 10th Nov 2008 at 22:26.
Please bear with me, I do know anything about the aircraft and it's systems, what I do know has been gleaned from this thread. It is not clear how the engineers disabled the RAT heater, from the diagrams posted earlier if it was disabled from the ccb this should have have not affected the other services from the relay R2-5. Much has been made of the aircraft being "in flying mode" causing the heater to be on, surely if the sensors thought that the aircraft was flying the TOWS was redundant as it was already "in the air".
If the procedure to check the TOWS before each TO was considered to be essential this should have been in the Flight Manual, if not, it cannot be considered to be mandatory.
Having been involved in the compilation of MEL's, they are considered to be a guide to acceptable deferred defects (ADD's) where for instance if an engine oil pressure guage is u/s:- as long as there is an alternative indication of low oil pressure, such as a low pressure warning light, it is acceptable to fly until a replacement guage can be installed, the reasons for the fatal flight appeared to be acceptable as icing was not to be expected during the flight.
If the procedure to check the TOWS before each TO was considered to be essential this should have been in the Flight Manual, if not, it cannot be considered to be mandatory.
Having been involved in the compilation of MEL's, they are considered to be a guide to acceptable deferred defects (ADD's) where for instance if an engine oil pressure guage is u/s:- as long as there is an alternative indication of low oil pressure, such as a low pressure warning light, it is acceptable to fly until a replacement guage can be installed, the reasons for the fatal flight appeared to be acceptable as icing was not to be expected during the flight.
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Oldlae, it has been said many times already: R2-5 failed stuck in air position causing rat heater to go on, and disabling TOWS.
Maintenance did not diagnose that, only remedy was to cut heater via CCB as MEL allows.
Maintenance did not diagnose that, only remedy was to cut heater via CCB as MEL allows.
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el,
Without wanting to sound like a stuck record, the aircraft was dispatched in accordance with the MEL. If you are dispatching an aircraft in accordance with the MEL, you are not carrying out any troubleshooting. You are deferring that action to a time that is more reasonably practicable. If the MEL says go, then go. If there is any ambiguity, then write a better MEL.
But on the counter to that, this appears to be an intermittent defect. If it s an intermittent defect, then the TOWS would have failed numerous times as well. Why was this not spotted by the various flight crews before when carrying out a TOWS check?
Without wanting to sound like a stuck record, the aircraft was dispatched in accordance with the MEL. If you are dispatching an aircraft in accordance with the MEL, you are not carrying out any troubleshooting. You are deferring that action to a time that is more reasonably practicable. If the MEL says go, then go. If there is any ambiguity, then write a better MEL.
But on the counter to that, this appears to be an intermittent defect. If it s an intermittent defect, then the TOWS would have failed numerous times as well. Why was this not spotted by the various flight crews before when carrying out a TOWS check?
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Intermitent means it comes and goes. They had several intermitent failures in the days prior to the accident involving the rat overtemp. Since the R2-5 relay controlled both rat heater and TOWS the TOWS would have failed too if checked at that time. It was the only relay of the eight or so that failed, controlled by the L nose gear oleo switch. The other relays on the same oleo circuit worked fine. The only way the rat heater can get power is through the R2-5 relay. Many mechanics must have missed the connection that the only way that could happen is if the relay was in de-energized air mode. The MEL they used was for an inop RAT heater. Obviously the heater was working fine but shouldn't have been powered on the ground. MEL's have to be read very carefully to make sure what you are doing is the intent of the MEL.
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The MEL should not be a crossword and should not need any careful reading. However, in practice they do and that is wrong. The conclusions from this investigation will hopefully lead to some changes, but that might be too late for the engineers being investigated and definitely for those crew and passengers who lost their lives.
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If you are dispatching an aircraft in accordance with the MEL, you are not carrying out any troubleshooting.
I'm fine with that.
My point is that when maintenance is called for any reason, cannot simply act robotically for the purpose on complying with a MEL, as the human brain is supposed to be engaged all the time - except perhaps when tragic errors are made like in this case.
Any engineer or technician knows that when a device supposed to be OFF automatically, remains ON instead , the problem CANNOT be in the device itself, instead SURELY is in the switch or logic powering such device.
If you think anyway that maintenance actions have been 100% correct (no case to respond), then consequenly these cannot even be a concurrent cause.
I just happen to think otherwise.
I'm fine with that.
My point is that when maintenance is called for any reason, cannot simply act robotically for the purpose on complying with a MEL, as the human brain is supposed to be engaged all the time - except perhaps when tragic errors are made like in this case.
Any engineer or technician knows that when a device supposed to be OFF automatically, remains ON instead , the problem CANNOT be in the device itself, instead SURELY is in the switch or logic powering such device.
If you think anyway that maintenance actions have been 100% correct (no case to respond), then consequenly these cannot even be a concurrent cause.
I just happen to think otherwise.
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"Any engineer or technician knows that when a device supposed to be OFF automatically, remains ON instead , the problem CANNOT be in the device itself, instead SURELY is in the switch or logic powering such device."
Yes, and after a few minutes this engineer decides to solve the problem by disabling the heater.
After more than 2 months and nearly 2500 posts it is very easy to say "the engineer should have known that the TOWS could be affected too" - but could he really?
Yes, and after a few minutes this engineer decides to solve the problem by disabling the heater.
After more than 2 months and nearly 2500 posts it is very easy to say "the engineer should have known that the TOWS could be affected too" - but could he really?
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Afm & Fom
Hello,
A fax or a telex by Boeing about about a critical operational item was an emergency action ... that required "follow-up".
And the normal way to make sure that everybody, present and future, will be provided with the correct information was to include that recommandation either in the Aircraft Flight Manual (FAA approved) or in the FOM (Boeing advisory stuff). Or to make it a service bulletin (Boeing responsibility) or an AD (FAA responsibility).
AD and AFM revision if it is considered as a modification required for the continuous airworthiness of the aircraft.
SB and FOM if it is considered just as a Boeing recommandation.
If Boeing did not proceed like that, they are at fault for not disseminating a critical information along the standard channels. Then neither the national authorithies, nor the company would be kept accountable for not taking into account a 20 years old sheet of paper that doesn't fit in the standard information package that comes with an aircraft, and that is meant to be updated as often necessary.
By the way, it was reported somewhere that Spannair had recently undergone an audit by Boeing, with honors.
So ?
Originally Posted by justme69
I also know that many operators claim they NEVER WERE NOTIFIED of the recommendation. Plenty of them flying around up until very recently. As you very well say, for over 20 years since it was made.
I know Boeing CLAIMS they notified it to all operators that AT THAT TIME were using MD-80's. I also know that Spanair (and others) didn't exist at that time and started their operations AFTER the recommendation was sent out.
I know Boeing CLAIMS they notified it to all operators that AT THAT TIME were using MD-80's. I also know that Spanair (and others) didn't exist at that time and started their operations AFTER the recommendation was sent out.
And the normal way to make sure that everybody, present and future, will be provided with the correct information was to include that recommandation either in the Aircraft Flight Manual (FAA approved) or in the FOM (Boeing advisory stuff). Or to make it a service bulletin (Boeing responsibility) or an AD (FAA responsibility).
AD and AFM revision if it is considered as a modification required for the continuous airworthiness of the aircraft.
SB and FOM if it is considered just as a Boeing recommandation.
If Boeing did not proceed like that, they are at fault for not disseminating a critical information along the standard channels. Then neither the national authorithies, nor the company would be kept accountable for not taking into account a 20 years old sheet of paper that doesn't fit in the standard information package that comes with an aircraft, and that is meant to be updated as often necessary.
By the way, it was reported somewhere that Spannair had recently undergone an audit by Boeing, with honors.
So ?
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MUC089, note I never said (and I don't think neither) that "the engineer should have known that the TOWS could be affected too".
I think that just taking on the problem with an "electrical mindset" would have guaranteed focus to be about the power circuit and not the RAT heater itself, even without knowing or remembering about the relation with TOWS, it would have been enough.
Note I say that having the most respect toward Engineers category (I'm one, but in a different industry) and with the most compassion for specific individual involved.
From the preliminary report I see that he may have been present at the A/C for 15 minutes the most, perhaps less. That can not be enough time to correctly address (even just identify) "strange" or intermittent problems. I think it was also reasonable for the Cap.n to accept the actions taken without questioning on the rationale (to each own his job) and just go for second T/O.
I think that just taking on the problem with an "electrical mindset" would have guaranteed focus to be about the power circuit and not the RAT heater itself, even without knowing or remembering about the relation with TOWS, it would have been enough.
Note I say that having the most respect toward Engineers category (I'm one, but in a different industry) and with the most compassion for specific individual involved.
From the preliminary report I see that he may have been present at the A/C for 15 minutes the most, perhaps less. That can not be enough time to correctly address (even just identify) "strange" or intermittent problems. I think it was also reasonable for the Cap.n to accept the actions taken without questioning on the rationale (to each own his job) and just go for second T/O.
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MEL
I have heard an old timer reporting to the dispatch :
"There are 42 open items in the Hold Items List (old termninology). I cannot cope with so many defects. I do not accept that aircraft."
And the aircraft was towed back to the hangar ...
There is a provision in the MEL's : final responsibility to accept flying with the defects lies in the captain judgement.
This means that the captain has to carefully analyse each reported defect, and the possible cumulative effects of multiple defects.
Yes, the captain is supposed to know the aircraft systems in depth ... and to have good judgement.
"There are 42 open items in the Hold Items List (old termninology). I cannot cope with so many defects. I do not accept that aircraft."
And the aircraft was towed back to the hangar ...
There is a provision in the MEL's : final responsibility to accept flying with the defects lies in the captain judgement.
This means that the captain has to carefully analyse each reported defect, and the possible cumulative effects of multiple defects.
Yes, the captain is supposed to know the aircraft systems in depth ... and to have good judgement.
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system study, analysis and touble shooting
Eight years ago, nearing the end of my flying career, I was finaly thaught how to study a "system" in an aircraft ...
1. Look at the main "power" part of the system : where is the power coming from, what are the normal and abnormal flowspaths of power (power could be electrical, hydraulic, pneumatic ... or even "manual")
2. Look at the controlling circuit(s) : how is the power activated, regulated, diverted, cancelled ...
3. Look at the indictors circuit(s)
4. Look at interaction with other systems ...
This is a very usefull way to simplify system diagrams! Just use 3 colors to "mark" the diagrams line and components ...
A good way do diagnose troubles ...
So quick in the Spannair RAT cause!
a) we have power ... so the power circuit is ok (there are no dedicated indicators, but we can feel the heat, use the aircraft ammeters, or a technician ammeter/voltmeter/ohmmeter standard tool).
b) So the problem must lies within the controlling circuit. What is the controlling circuit made off? That infamous relay!
Bingo!
c) How can we make sure ? See what other system are controlled by this relay ... So easy to test the TOWS ... Double Bingo!
1. Look at the main "power" part of the system : where is the power coming from, what are the normal and abnormal flowspaths of power (power could be electrical, hydraulic, pneumatic ... or even "manual")
2. Look at the controlling circuit(s) : how is the power activated, regulated, diverted, cancelled ...
3. Look at the indictors circuit(s)
4. Look at interaction with other systems ...
This is a very usefull way to simplify system diagrams! Just use 3 colors to "mark" the diagrams line and components ...
A good way do diagnose troubles ...
So quick in the Spannair RAT cause!
a) we have power ... so the power circuit is ok (there are no dedicated indicators, but we can feel the heat, use the aircraft ammeters, or a technician ammeter/voltmeter/ohmmeter standard tool).
b) So the problem must lies within the controlling circuit. What is the controlling circuit made off? That infamous relay!
Bingo!
c) How can we make sure ? See what other system are controlled by this relay ... So easy to test the TOWS ... Double Bingo!
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Bis47,
I do not believe anybody is calling into question the engineers troubleshooting skills, because in all probability no troubleshooting was carried out. You are trained to dispatch an aircraft in a safe and timely manner. If it is on the deck for a number of hours, you would start troubleshooting, If you are called to an aircraft that has returned to stand, you go to the MEL. If you cannot find a relevant section in the MEL for the defective item that you have, it means that it is either an non airworthiness item or it is a no dispatch.
It appears that the fault was diagnosed as a heater problem and action was taken just for that and the RAT heater CB was tripped. As I have said before, if any changes are made to any procedure after the investigation has finished, then the problem does not lie with the engineers. If all the procedures remain the same, then the judge will be stating that the level of knowledge and training of the engineers involved should have been enough for them to understand that the problem was that a relay was in the wrong sense, so causing the RAT heater to be on when it should be off and that the use and understanding of the MEL was incorrect.
I do not believe anybody is calling into question the engineers troubleshooting skills, because in all probability no troubleshooting was carried out. You are trained to dispatch an aircraft in a safe and timely manner. If it is on the deck for a number of hours, you would start troubleshooting, If you are called to an aircraft that has returned to stand, you go to the MEL. If you cannot find a relevant section in the MEL for the defective item that you have, it means that it is either an non airworthiness item or it is a no dispatch.
It appears that the fault was diagnosed as a heater problem and action was taken just for that and the RAT heater CB was tripped. As I have said before, if any changes are made to any procedure after the investigation has finished, then the problem does not lie with the engineers. If all the procedures remain the same, then the judge will be stating that the level of knowledge and training of the engineers involved should have been enough for them to understand that the problem was that a relay was in the wrong sense, so causing the RAT heater to be on when it should be off and that the use and understanding of the MEL was incorrect.
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Yes, that is exactly it. No troubleshooting, not bad troubleshooting. You could stop this ever happening again and take MEL's off of the aircraft.
If the Captain had not noticed the RAT heater was heating on the ground, would the aircraft still have crashed?
If the Captain had not noticed the RAT heater was heating on the ground, would the aircraft still have crashed?
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Bis47,
If you are called to an aircraft that has returned to stand, you go to the MEL. If you cannot find a relevant section in the MEL for the defective item that you have, it means that it is either an non airworthiness item or it is a no dispatch.
It appears that the fault was diagnosed as a heater problem ...
If you are called to an aircraft that has returned to stand, you go to the MEL. If you cannot find a relevant section in the MEL for the defective item that you have, it means that it is either an non airworthiness item or it is a no dispatch.
It appears that the fault was diagnosed as a heater problem ...
I wonder, did they test the heater, and did it pass ?
Should it be a reasonable expectation for engineer to realise that if a heating element heats up when it isn't supposed to, then the heater is not broken (which is what the MEL deals with), something else is broken ?
We don't need to get as far as whether we can expect the engineer (at the stand) to realise this is a air-ground sensing fault (although some might, if they've seen it before), just to get as far as realising that something other than the heater is broken.