SAS Q400 gear collaps CPH 27/10
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Dehavilland Canada & now BBD, have an excellent reputation for making some of the finest Canadian turbo prop aircraft
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have an excellent reputation for making some of the finest Canadian turbo prop aircraft worldwide.
Re-word: these Canadian built turbo props are recognized as some of the finest regional aircraft worldwide.
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Flaps2billion:
Here is the link to the 3 prelim. reports so far on the third accident: http://www.hcl.dk/sw152431.asp
Pick your favourite length
Here is the link to the 3 prelim. reports so far on the third accident: http://www.hcl.dk/sw152431.asp
Pick your favourite length
So far 18 SAS Dash8-400's
have been checked. In 16 of them the before mentioned Hydraulic filter was either defect or missing and in 2 cases an O ring was found in the hydraulic fluid.
http://www.berlingske.dk/article/200...ark/701240007/
http://www.berlingske.dk/article/200...ark/701240007/
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"...have been checked. In 16 of them the before mentioned Hydraulic filter was either defect or missing and in 2 cases an O ring was found in the hydraulic fluid."
Miraculix,
Many thanks for that post. I'm assuming that the above is a summary of the newspaper article in the link? (Oh if only I hadn't skipped Danish classes in school). Sounds very embarrassing.
When you say two o-ring particles - I wonder does that mean two in addition to the crash-landed plane, or does that figure include the crash-lander?
A missing filter is rather a poor show but, from my limited knowledge of hydraulics, many systems can tolerate quite a considerable amount of sludge and, to a limited degree, could tolerate a missing filter (providing there are no large bodies like o-ring particles). A defective or completely blocked filter is another matter and, unless there is some sort of fail-safe or emergency bypass, or a complete alternative B system, could result in no pressure getting through to an effective component.
Wonder where the additional 0-ring particles were found? In the actuator where they possibly originated, in a filter, or swishing around in the general body of fluid?
Where the air is rarified, we'll just glide, starry-eyed ...
Miraculix,
Many thanks for that post. I'm assuming that the above is a summary of the newspaper article in the link? (Oh if only I hadn't skipped Danish classes in school). Sounds very embarrassing.
When you say two o-ring particles - I wonder does that mean two in addition to the crash-landed plane, or does that figure include the crash-lander?
A missing filter is rather a poor show but, from my limited knowledge of hydraulics, many systems can tolerate quite a considerable amount of sludge and, to a limited degree, could tolerate a missing filter (providing there are no large bodies like o-ring particles). A defective or completely blocked filter is another matter and, unless there is some sort of fail-safe or emergency bypass, or a complete alternative B system, could result in no pressure getting through to an effective component.
Wonder where the additional 0-ring particles were found? In the actuator where they possibly originated, in a filter, or swishing around in the general body of fluid?
Where the air is rarified, we'll just glide, starry-eyed ...
It dos'nt specify if the o-ring in the "crashlander" is in the tally.
My own translation, please don't smack me for faults...
SAS flew dangerous planes for years
27 aircraft had dangerous, but hidden designflaws.
First SAS found corrosion in 25 out of 27 Dash8 aircraft. Now a new inspection shows, that something was wrong with a filter in the landinggear. Writes danish newspaper Politikken.
SAS has for years been flying around with 27 Dash8 aircraft, that had serious, but hidden designflaws. After two emergency landings in september last year it was revealed, that 25 out of 27 aircraft had corrosion in the landinggear.
Now a new inspection from SAS reveales, that also the hydraulic system in the landinggear on most planes was flawed. So far 18 of the 27 aircraft has been inspected and 16 of these has had either defect or totally missing filters.
I a minimum of two cases an o-ring was in the hydraulic system. SAS had no chance of finding the corrosion or the flawed filters. The corrosion was in a piston, that should only be inspected after about 10 years use - SAS recieved their aircraft in 2000.
The European agency, EASA, that type approves the aircraft flying in Europe, was on january 10 this year notified by mail with documentation that, SAS had found defect filters en almost all inspected aircraft.
The notification came from Statens luftfartsvæsen (SLV) (the Danish CAA), that at the moment is in charge of the three scandinavian countries overseeing SAS.
SLV had, before SAS found the many falts, assesed, that there was a designflaw.
Allready then EASA said after a meeting with among others the Dash8 constructor, Canadian Bombardier, that the crash on 27 october i Copenhagen Kastrup was a unique fault and therefore was of no importance to other Dash8's.
Now in almost all inspected SAS aircraft defect filters has been found. But EASA is not changing their view. Allready on january 11, the day after the mail from SLV, the technical director of EASA answered in a mail, that:"the found faults will only be critical in a combination with maintanance faults".
EASA still decline, that its a designflaw, but at the same time adds:"Bombardier is designing a new filter".
SLV is standing fast on its view that its a designflaw.
"the scandinavian CAA's are not on par with the view of EASA" says Per Veingberg, technical director of SLV to Politikken. He says the crash on 27 october, was caused by the defect filter, that was flawed in design. SAS does not want to comment the new inspection and it was not possible to get in contact with Bombadier.
My own translation, please don't smack me for faults...
SAS flew dangerous planes for years
27 aircraft had dangerous, but hidden designflaws.
First SAS found corrosion in 25 out of 27 Dash8 aircraft. Now a new inspection shows, that something was wrong with a filter in the landinggear. Writes danish newspaper Politikken.
SAS has for years been flying around with 27 Dash8 aircraft, that had serious, but hidden designflaws. After two emergency landings in september last year it was revealed, that 25 out of 27 aircraft had corrosion in the landinggear.
Now a new inspection from SAS reveales, that also the hydraulic system in the landinggear on most planes was flawed. So far 18 of the 27 aircraft has been inspected and 16 of these has had either defect or totally missing filters.
I a minimum of two cases an o-ring was in the hydraulic system. SAS had no chance of finding the corrosion or the flawed filters. The corrosion was in a piston, that should only be inspected after about 10 years use - SAS recieved their aircraft in 2000.
The European agency, EASA, that type approves the aircraft flying in Europe, was on january 10 this year notified by mail with documentation that, SAS had found defect filters en almost all inspected aircraft.
The notification came from Statens luftfartsvæsen (SLV) (the Danish CAA), that at the moment is in charge of the three scandinavian countries overseeing SAS.
SLV had, before SAS found the many falts, assesed, that there was a designflaw.
Allready then EASA said after a meeting with among others the Dash8 constructor, Canadian Bombardier, that the crash on 27 october i Copenhagen Kastrup was a unique fault and therefore was of no importance to other Dash8's.
Now in almost all inspected SAS aircraft defect filters has been found. But EASA is not changing their view. Allready on january 11, the day after the mail from SLV, the technical director of EASA answered in a mail, that:"the found faults will only be critical in a combination with maintanance faults".
EASA still decline, that its a designflaw, but at the same time adds:"Bombardier is designing a new filter".
SLV is standing fast on its view that its a designflaw.
"the scandinavian CAA's are not on par with the view of EASA" says Per Veingberg, technical director of SLV to Politikken. He says the crash on 27 october, was caused by the defect filter, that was flawed in design. SAS does not want to comment the new inspection and it was not possible to get in contact with Bombadier.
Last edited by Miraculix; 24th Jan 2008 at 17:07. Reason: SPELLING!!!
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Miraculix,
Brilliant translation. No smacks.
Seems the local Aviation Authority is backing up SAS against the opinions of the Easa. That will be an interesting turf war to watch. Lot of self-serving interpretation going there, methinks.
Wonder if any other airline flying the type experienced the same level of problems? For example, corroded pistons are often a function of contaminants in the fluid, mostly water, which is a common contamination due to moisture precipitating out of air in the system. Routine maintenance should deal with it.
The final report into those incidents will be interesting to read.
Brilliant translation. No smacks.
Seems the local Aviation Authority is backing up SAS against the opinions of the Easa. That will be an interesting turf war to watch. Lot of self-serving interpretation going there, methinks.
Wonder if any other airline flying the type experienced the same level of problems? For example, corroded pistons are often a function of contaminants in the fluid, mostly water, which is a common contamination due to moisture precipitating out of air in the system. Routine maintenance should deal with it.
The final report into those incidents will be interesting to read.
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Perhaps not the most perfect aircraft in aviation history but I doubt if such a basic bog-standard system as the Q400's hydraulics would have passed certification on both sides of the Atlantic if items like filters, and maintenance intervals, were not up to scratch. Makes you think.
They certainly had a design-and/or-maintenance problem with the actuator rod threads but again we must wait for the final report to see if there wasn't a mitigating factor. Absolutely ignorant of things like de-icing fluids but have seen suggestions (which may have been self-serving on someone's part) that this may have been cused by a particular type of fluid which reacted poorly with the u/c.
They certainly had a design-and/or-maintenance problem with the actuator rod threads but again we must wait for the final report to see if there wasn't a mitigating factor. Absolutely ignorant of things like de-icing fluids but have seen suggestions (which may have been self-serving on someone's part) that this may have been cused by a particular type of fluid which reacted poorly with the u/c.
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SAS has for years been flying around with 27 Dash8 aircraft, that had serious, but hidden designflaws
Since when would a faulty filter constitute as a major design flaw?
I a minimum of two cases an o-ring was in the hydraulic system. SAS had no chance of finding the corrosion or the flawed filters. The corrosion was in a piston, that should only be inspected after about 10 years use - SAS recieved their aircraft in 2000.
They mention nothing about where the corrosion came from?
After looking at the facts, I do believe that the faulty filter may have been a reason for the third. Maybe something during the inspections triggered it?? Who knows??
But this article tries to blame the first two on BBD with no substance at all! Corrosion? Where did the corrosion come from & how? Why no other airline?
the technical director of EASA answered in a mail, that:"the found faults will only be critical in a combination with maintanance faults".
"the scandinavian CAA's are not on par with the view of EASA"
SAS flew dangerous planes for years
I found this article extremely shameful! Without any final report, they already come to a conclusion! Is this the way news is presented to people in Denmark?
They try to link the first two accidents with the third without any proper reasoning!
Transport Canada does not do this, the FAA does not do this & the media on our side of the pond does not make loaded statements without a final report. At least they use words like suspect or possible!
The Q400 is still manufactured the same way! Does this mean that Flybe, Horizon, ANA, Austrian, Porter, Frontier.... have flying dangerous airplanes?
This is how you ruin reputations! The average reader who is not into aviation won't know better. They can easily be fooled by loaded statements!
In my 15 years of flying pros.....I have never seen something this ridiculous!
Is the SLV looking for the truth or are they trying to defend SAS?
Anyways, let's cut the talk & see what the final report says!
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Flaps2billion wrote:
"After looking at the facts, I do believe that the faulty filter may have been a reason for the third. Maybe something during the inspections triggered it?? Who knows??"
Actually the interim report report from the official Danish investigation suggests the o-ring fragment was probably introduced into the actuator with the swap-over when they replaced a corroded u/c actuator with a similar, but perhaps not identical, part used to open the front nose-wheel door. So it was (inadvertantly) put directly in the business end of the system and could not have otherwise passed through the system. Don't know the layout of the system but perhaps a filter, even if present, might not have been in the right place to catch it.
See: http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf
"After looking at the facts, I do believe that the faulty filter may have been a reason for the third. Maybe something during the inspections triggered it?? Who knows??"
Actually the interim report report from the official Danish investigation suggests the o-ring fragment was probably introduced into the actuator with the swap-over when they replaced a corroded u/c actuator with a similar, but perhaps not identical, part used to open the front nose-wheel door. So it was (inadvertantly) put directly in the business end of the system and could not have otherwise passed through the system. Don't know the layout of the system but perhaps a filter, even if present, might not have been in the right place to catch it.
See: http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf
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Actually I'm perhaps jumping to conclusions in my last post when I say the replaced actuator was corroded. All we really know is that one, part of the system to open the wheel bay doors, was replaced and that replacement introduced the o-ring fragment which ultimately blocked an orifice in a downstream component which prevented the undercarriage extending.
http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf
http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf
I read in today´s ATW Daily News concerning the main landing gear:
SAS technical Dpt has found problems in 63 % of the SSV valves on the grounded Q400s.
"The SSV valve has a construction error and is currently being modified by the supplier", SAS concluded.
I take it SAS means Goodrich is modifying the valve design. While this probably is not "a major design flaw in the aircraft", surely this, if true, means that not everything can be blamed on SAS maintenance?
SAS technical Dpt has found problems in 63 % of the SSV valves on the grounded Q400s.
"The SSV valve has a construction error and is currently being modified by the supplier", SAS concluded.
I take it SAS means Goodrich is modifying the valve design. While this probably is not "a major design flaw in the aircraft", surely this, if true, means that not everything can be blamed on SAS maintenance?
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flaps2billion:
Are you serious??? Talk about a loaded statement.... 
the media on our side of the pond does not make loaded statements without a final report. At least they use words like suspect or possible!
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I take it SAS means Goodrich is modifying the valve design. While this probably is not "a major design flaw in the aircraft", surely this, if true, means that not everything can be blamed on SAS maintenance?
But to make statments such as, "SAS flew dangerous planes for years", without any final report is wrong!
If I were a BBD employee working on the Q400, I would be super upset! Remeber that Goodrich makes the landing gears, not BBD.
So far SAS is the only one complaining, makes you wonder?
Are you serious??? Talk about a loaded statement....
Does anybody know where I can find the writer's email address for the article? Sorry don't know the language...
Breaking through the chit-chat here ......
I think several of us would be interested to know what has happened to the aircraft, because this may give a hint about their future.
Are they stored by SAS and Wideroe ? Notes elsewhere say they have gone from their initial parking points. Have they returned to North America ?
Also what has happened to the three involved in the landing incidents ? Have they been repaired, broken up for scrap, or stored damaged pending a decision ?
I think several of us would be interested to know what has happened to the aircraft, because this may give a hint about their future.
Are they stored by SAS and Wideroe ? Notes elsewhere say they have gone from their initial parking points. Have they returned to North America ?
Also what has happened to the three involved in the landing incidents ? Have they been repaired, broken up for scrap, or stored damaged pending a decision ?