SAS Q400 gear collaps CPH 27/10
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As I read the EASA comment, they are addressing the Scandinavian authorities, not SAS. The Scandi CAA's grounded the Q400's due to safety concerns after the 3rd accident, and no other CAA followed this, thus being "temporarily out of line with the rest of the 31 EASA member nations."
The critiscism is at authority-level, not directed at SAS, as far as I'm concerned. And EASA would have no business at all interfering with or commenting on SAS' commercial descisions.
The critiscism is at authority-level, not directed at SAS, as far as I'm concerned. And EASA would have no business at all interfering with or commenting on SAS' commercial descisions.
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MP:
You're right, that the O-ring shouldn't be there. And I'm sure that you have read the 3rd prelim report at http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf.
IMO you're a bit to quick to write off Bombardiers responsability. Apparently there is a history of the filterelement with the particular O-ring attached, which can
We probably agree, that thats not supposed to happen in the first place. I'm not so convinced, that Bombardier can't be blamed for anything, at this point. So I'm saying: it's too early to say, that is probably due to "poor maintenance procedures" (unless we talk about about "maintenance procedures" in its broadest way, including the manufacturer and their actions)
But the investigation will shed more light on this, I'm sure.
You're right, that the O-ring shouldn't be there. And I'm sure that you have read the 3rd prelim report at http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf.
IMO you're a bit to quick to write off Bombardiers responsability. Apparently there is a history of the filterelement with the particular O-ring attached, which can
collapse and migrate into the landing gear hydraulic system.
But the investigation will shed more light on this, I'm sure.
Severe CAVOK : Apparently there is a history of the filterelement with the particular O-ring attached, which can
Quote:
collapse and migrate into the landing gear hydraulic system.
Quote:
collapse and migrate into the landing gear hydraulic system.
A review of the aircraft’s hydraulic system concluded that the rogue O-Ring could not have traveled from the SSV to its final location in the right main landing gear retraction/extension actuator restrictor valve.
Not a bad read, I think it was the butler in the kitchen with a candle stick, but I'm happy to wait for the final report to find out
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Do you dear to land the Dash?
http://www.dr.dk/spil/dashncrash/
IMHO is the D8-400 a dead bird at least in Scandinavia, due to media. This has nothing to do with any resolution from Bombardier/operators to construction- or maintenance problems.
http://www.dr.dk/spil/dashncrash/
IMHO is the D8-400 a dead bird at least in Scandinavia, due to media. This has nothing to do with any resolution from Bombardier/operators to construction- or maintenance problems.
gramlin
Had some fun with that, but even a "god" landing ends in a dash or should I say crash.
And yes the withdrawel of the dash from SAS inventory is all down to SAS having to do something. The public in scandinavia has endured the dash from the beginning and it seems 7 years of unreliability and 3 bellylandings is what it takes.
But before the rest of the world belittles scandinavians, remember they were the guinypigs from the start and don't forget all the returns, aborted takeoffs, delays and whatnot because of: A/C generator fails, cargofire warnings, door open warnings, stuck flaps, com fails, powerplant messages, gear problems, stuck deicer boot valves and the list goes on and on and on..........
Rumor says that the dash -400 caused 70% of all firebrigade callouts i Copenhagen, so they can relax now after 7 hard years.
I think the dash is about to become an ok plane and I'm shure in another 7 years time it might even be great.
And yes the withdrawel of the dash from SAS inventory is all down to SAS having to do something. The public in scandinavia has endured the dash from the beginning and it seems 7 years of unreliability and 3 bellylandings is what it takes.
But before the rest of the world belittles scandinavians, remember they were the guinypigs from the start and don't forget all the returns, aborted takeoffs, delays and whatnot because of: A/C generator fails, cargofire warnings, door open warnings, stuck flaps, com fails, powerplant messages, gear problems, stuck deicer boot valves and the list goes on and on and on..........
Rumor says that the dash -400 caused 70% of all firebrigade callouts i Copenhagen, so they can relax now after 7 hard years.
I think the dash is about to become an ok plane and I'm shure in another 7 years time it might even be great.
Last edited by Miraculix; 6th Nov 2007 at 09:41.
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This little game shows exactly why SAS had to ditch the dash.
Last edited by DK_FCI; 6th Nov 2007 at 12:57.
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Opaerator Message from Bombardier
The following message is being sent to all Bombardier Aerospace Regional Aircraft Q400 Operators and Bombardier Aerospace Regional Aircraft Field Service Representatives.
DISCUSSION:
As a result of the information contained in the preliminary report, attached below, Operators are advised that should a Solenoid Sequence Valve (SSV) or Mechanical Sequence Valve (MSV) be replaced, care should be taken to ensure that FOD is not collected and transferred during the replacement of serviceable unit/s.
Although highly improbable that the transfer of such FOD would have a major impact on the hydraulic system, under special circumstances the migration of such FOD could cause the landing gear system to malfunction.
Operators are encouraged to ensure that only official documentation is used when changing components, that unions and fixtures on the SSV and MSV are not swapped out with alternative components without thorough care and cleaning, and only if following approved, documented procedures.
Under normal circumstances, FOD will be captured by the existing filters and valves but unapproved procedures without care can bypass these safeguards.
DISCUSSION:
As a result of the information contained in the preliminary report, attached below, Operators are advised that should a Solenoid Sequence Valve (SSV) or Mechanical Sequence Valve (MSV) be replaced, care should be taken to ensure that FOD is not collected and transferred during the replacement of serviceable unit/s.
Although highly improbable that the transfer of such FOD would have a major impact on the hydraulic system, under special circumstances the migration of such FOD could cause the landing gear system to malfunction.
Operators are encouraged to ensure that only official documentation is used when changing components, that unions and fixtures on the SSV and MSV are not swapped out with alternative components without thorough care and cleaning, and only if following approved, documented procedures.
Under normal circumstances, FOD will be captured by the existing filters and valves but unapproved procedures without care can bypass these safeguards.
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I have done my reserach and apparently SAS has had some troubles within it's maintanence dep. before......
SAS Q400 accident probe points to maintenance error
By David Kaminski-Morrow
Danish investigators are indicating that a maintenance error led to the landing-gear actuator blockage which led a Scandinavian Airlines Bombardier Q400 to conduct a gear-up landing at Copenhagen last month.
It follows their discovery that an O-ring from a newly-replaced door valve caused the blockage of a restrictor valve in the actuator assembly. The blockage prevented the right-hand landing-gear deploying.
The subsequent gear-up landing was the third suffered by a Scandinavian Airlines Q400 since early September and the carrier opted to remove the entire fleet permanently from service.
But while the underlying reasons for the first two accidents, which resulted from actuator corrosion, have yet to be determined, Danish investigation agency HCL is suggesting that a maintenance error contributed to the third.
The finding lends support to claims from manufacturer Bombardier that there is no inherent problem with the aircraft.
HCL says that in-depth analysis of the Q400’s hydraulic system shows that the O-ring “could not have travelled” from the solenoid valve to the actuator because certain components, such as the mechanical sequence valve, would prevent passage.
But it points out that the right main landing-gear’s solenoid valve was replaced on 16 October and the mechanical sequence valve was replaced on 22 October – just five days before the Copenhagen accident.
Scandinavian Airlines replaced a number of landing-gear components on its entire fleet after the first two gear-up events, at Aalborg and Vilnius, on 9 and 12 September.
HCL says that, during replacement of the mechanical sequence valve, the rogue O-ring could have “unknowingly been transferred…by maintenance personnel” from one side of the valve to the other.
If this was the case, it says, the O-ring would have been able to travel through the hydraulic lines towards the landing-gear actuator. HCL states that the investigation is continuing and the organisation has yet to reach final conclusions.
But Bombardier says that the Danish evidence “clearly support” its view that the Q400 is “safe and reliable”. The manufacturer has been forced to defend the Q400 in the wake of the three closely-spaced Scandinavian Airlines accidents and the carrier’s decision to axe the type.
“We have unwavering confidence in the Q400 aircraft and we stand by our product,” says Bombardier Regional Aircraft president Steven Ridolfi.
“We are concerned about the impact negative comments might have had on Bombardier and the Q400 turboprop’s reputation and we will do all that is necessary to protect our brand and, by association, the reputation of our Q400 aircraft customers.”
By David Kaminski-Morrow
Danish investigators are indicating that a maintenance error led to the landing-gear actuator blockage which led a Scandinavian Airlines Bombardier Q400 to conduct a gear-up landing at Copenhagen last month.
It follows their discovery that an O-ring from a newly-replaced door valve caused the blockage of a restrictor valve in the actuator assembly. The blockage prevented the right-hand landing-gear deploying.
The subsequent gear-up landing was the third suffered by a Scandinavian Airlines Q400 since early September and the carrier opted to remove the entire fleet permanently from service.
But while the underlying reasons for the first two accidents, which resulted from actuator corrosion, have yet to be determined, Danish investigation agency HCL is suggesting that a maintenance error contributed to the third.
The finding lends support to claims from manufacturer Bombardier that there is no inherent problem with the aircraft.
HCL says that in-depth analysis of the Q400’s hydraulic system shows that the O-ring “could not have travelled” from the solenoid valve to the actuator because certain components, such as the mechanical sequence valve, would prevent passage.
But it points out that the right main landing-gear’s solenoid valve was replaced on 16 October and the mechanical sequence valve was replaced on 22 October – just five days before the Copenhagen accident.
Scandinavian Airlines replaced a number of landing-gear components on its entire fleet after the first two gear-up events, at Aalborg and Vilnius, on 9 and 12 September.
HCL says that, during replacement of the mechanical sequence valve, the rogue O-ring could have “unknowingly been transferred…by maintenance personnel” from one side of the valve to the other.
If this was the case, it says, the O-ring would have been able to travel through the hydraulic lines towards the landing-gear actuator. HCL states that the investigation is continuing and the organisation has yet to reach final conclusions.
But Bombardier says that the Danish evidence “clearly support” its view that the Q400 is “safe and reliable”. The manufacturer has been forced to defend the Q400 in the wake of the three closely-spaced Scandinavian Airlines accidents and the carrier’s decision to axe the type.
“We have unwavering confidence in the Q400 aircraft and we stand by our product,” says Bombardier Regional Aircraft president Steven Ridolfi.
“We are concerned about the impact negative comments might have had on Bombardier and the Q400 turboprop’s reputation and we will do all that is necessary to protect our brand and, by association, the reputation of our Q400 aircraft customers.”
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Anyway, that quote comes from flight international and I think it sums up what a lot of us thought. I guess all we can really do now is wait for the official report to confirm it and hopefully have a mature discussion on the rights and wrongs of SAS, EASA, Bombardiers and every other DHC8-Q400 operators reaction to the events.
Link to article
Link to article
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Interesting personal account of the Sept 10th incident in Aalborg. Especially the bit (Page 2) about the crew asking the poor guy to swap seats with an SAS pilot who was in direct line of fire from the props.
http://www.pda-online.org/documents/...gCrash0907.pdf
http://www.pda-online.org/documents/...gCrash0907.pdf
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Read the story again, jewitt.
They put the pilot next to the emergency exit, that's pretty much standard procedure. He is trained on emergency procedures, and is the best choice for this position.
The crew moved the passengers away from the right prop area, a decision which most likely saved lives.
They put the pilot next to the emergency exit, that's pretty much standard procedure. He is trained on emergency procedures, and is the best choice for this position.
The crew moved the passengers away from the right prop area, a decision which most likely saved lives.
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ManaAdaSystem: I'm not saying it is wrong to put an experienced person (pilot) at the exit row. But if it were me, I would have politely refused to move in-line with the propellors, even on the left side. Surely there is a case to re-look at the safety of these types of propellor. I know that the outer skin is reinforced on some prop aircraft. I seem to recall one design that doesn't have windows on that particular seat row. Surely the technology already exists. The Kevlar used in bullet proof vests for example. Lightweight and strong enough to stop pieces of composite propellor.
jewitts
Are you trying a windup here? Noone was sitting in line with the props! I say again NOONE was sitting in line with the props!
If you read the report, people was moved away from the prop area, but where fragment from the prop goes is anybody's guess.
If you read the report, people was moved away from the prop area, but where fragment from the prop goes is anybody's guess.
Well if you wrapped the kevlar belt arround the fuselage for a fair distance forward and aft of the props, then when a prop failed the belt would still be there with the prop blade stuck in it, but the fuselage would be crushed almost all the way arround by the deflecting belt, not good for flyback purposes.
Give a thought to the prop trajectory and tumble as well. It reminds me of a bolo, it can't miss creating a 180 degree swath or more of damage.
Give a thought to the prop trajectory and tumble as well. It reminds me of a bolo, it can't miss creating a 180 degree swath or more of damage.
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Miraculix: No wind-up intended.
I'm qouting from the newspaper article here:
"I moved to an aisle seat on the left-hand side of the plane, which was right in line with the two
propellers," Primeaux explained. "I was not comfortable about this but felt since the crew had
me move, all would be OK. It did, at one time, cross my mind that if something happened, the
prop could come through the side of the plane and hit me."
In hindsight, Primeaux said that if he would have remained in his assigned seat, he may have
not received the cut to his hand because after the crash those seated in Row 2 did not sustain
any injuries."
To me, that means that they did not move people away from the prop area on this occasion. Or am I wrong? I know they moved people on the later incidents but for the Aalborg one, seems not?
Otherwise I think the eye witness account is quite comprehensive, accurate and very interesting.
I'm qouting from the newspaper article here:
"I moved to an aisle seat on the left-hand side of the plane, which was right in line with the two
propellers," Primeaux explained. "I was not comfortable about this but felt since the crew had
me move, all would be OK. It did, at one time, cross my mind that if something happened, the
prop could come through the side of the plane and hit me."
In hindsight, Primeaux said that if he would have remained in his assigned seat, he may have
not received the cut to his hand because after the crash those seated in Row 2 did not sustain
any injuries."
To me, that means that they did not move people away from the prop area on this occasion. Or am I wrong? I know they moved people on the later incidents but for the Aalborg one, seems not?
Otherwise I think the eye witness account is quite comprehensive, accurate and very interesting.
One of the great advantages of composite props are a reduction in weight, this reduces the likelihood of a prop blade coming thru the fuselage. a while back the ANZ airlink b1900 belly landing pix showed this. All the prop blades airborne right after touch down. If somebody can find this pic and post olease
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It´s SOP to reseat pax if needed but if the plane is full or nearly full, somebody will have to sit in the row between the props.
If the cabin crew orders you to move from an emergency exit to make room for a "pax-pilot", you have to move or they can take you to court for endangering the other pax, flight safety.
If the cabin crew orders you to move from an emergency exit to make room for a "pax-pilot", you have to move or they can take you to court for endangering the other pax, flight safety.
ANZ Beech 1900 landing. Video on YouTube, search by Beech 1900 and you'll find it. For excellent stills of the prop disintegrating google Beech 1900 ANZ in Google Images.