Spanair accident at Madrid
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Some more elaboration from the media in Spain.
August 17th (3 days before the accident) the airplane was subjected to a revision by two company technicians after the RIGHT engine showed a diagnosis light on the reverser (more precisely , the electronic control system to deploy it), according to documentation given to the judge. Some anomaly on a valve on the hydraulic system involved with the device was found as the cause. No leaks could be found.
It's unclear at this point (conflicting reports) if the fault was (thought to be) fixed or if the repairs were delayed and the reverser locked-out of service. Most sources speak of the item repair being delayed and the pilots knowing about it and unable to make use of the device, other (one source) speaks of it having been fixed. Regardless, everyone agrees it wasn't necessary to have it working for the flight (both airstrips were long enough).
The reverser has appeared deployed on that RIGHT engine according to most sources, while one major newpapers explicitly RETRACTS the previous information and now says that it was the LEFT engine that was found with the deployed reverser.
Of course it could've been deployed on purpose while on the ground and trying to brake, or become loose from the impacts, etc.
Aiport ground radar data was reviewed and found the airplane to reach 170kt (error marging up to 30km/h). Regardless, seemed to have reached enough speed to rotate and lose contact with the ground.
That same plane had an aborted T/O less than a month ago by another pilot flying Mallorca-Copenhagen because he observed "excessive noise from the landing gear".
August 17th (3 days before the accident) the airplane was subjected to a revision by two company technicians after the RIGHT engine showed a diagnosis light on the reverser (more precisely , the electronic control system to deploy it), according to documentation given to the judge. Some anomaly on a valve on the hydraulic system involved with the device was found as the cause. No leaks could be found.
It's unclear at this point (conflicting reports) if the fault was (thought to be) fixed or if the repairs were delayed and the reverser locked-out of service. Most sources speak of the item repair being delayed and the pilots knowing about it and unable to make use of the device, other (one source) speaks of it having been fixed. Regardless, everyone agrees it wasn't necessary to have it working for the flight (both airstrips were long enough).
The reverser has appeared deployed on that RIGHT engine according to most sources, while one major newpapers explicitly RETRACTS the previous information and now says that it was the LEFT engine that was found with the deployed reverser.
Of course it could've been deployed on purpose while on the ground and trying to brake, or become loose from the impacts, etc.
Aiport ground radar data was reviewed and found the airplane to reach 170kt (error marging up to 30km/h). Regardless, seemed to have reached enough speed to rotate and lose contact with the ground.
That same plane had an aborted T/O less than a month ago by another pilot flying Mallorca-Copenhagen because he observed "excessive noise from the landing gear".
Last edited by justme69; 28th Aug 2008 at 11:53.
"The INTRODUCER"
Incidents related to performance calculations
I cite these two previous incidents below simply to show that it is surprising how large an error in performance calcs a crew will accept. (I'm the author of the first of the stories.)
Some posts above have suggested that an error in V speeds of sufficient magnitude to cause this accident was inconceivable. I'm not implying I have any insight into whether this was a factor at Madrid or not - but I do think these incidents make it clear that the notion is not out of the question.
Somebody out there may know whether the procedures/kit used by Spanair are the same as SAS, which I think is likely given their commercial/operational relationship. And you may have opinions on the subtle factors at play with the trend to uplinked weights and/or V speeds.
SAS probes procedures after close call on take-off
Kieran Daly, London (03Sep99, 12:16 GMT, 759 words)
SAS is reviewing its cockpit procedures after a Boeing 767 came close to catastrophe on take-off when the crew used the wrong aircraft weight for its performance calculations.
The captain of the Tokyo-bound 767-300ER aborted take-off at Copenhagen after rotation when he realised something was wrong and managed to stop inside the length of the airport's 3,570m (11,713ft) runway 22R from a speed of around 140kt (260km/hr).
The aircraft suffered a minor tailstrike and burst tyres and it has since been established that the crew had entered the aircraft's zero fuel weight (ZFW) instead of its gross weight - about a 65t difference.
SAS, which recently changed its procedure for calculating take-off speeds - switching from using a hand-held computer in the cockpit to the use of the ACARS (aircraft communications addressing and reporting system) datalink to have the final calculation performed elsewhere - is now trying to see if there is a way to reduce the chance of a repetition.
A senior Captain involved in the review tells ATI: "This happened to a very experienced professional colleague of mine. My first thought was that if this can happen to a solid fellow like this then it can happen to anyone. So we have to look into it and see what we can do."
Another SAS official - director of flight operations in Denmark, Fleming Jeppsson - relates how in the 24 August incident the co-pilot was conducting the take-off and rotated the aircraft at the calculated speed (VR).
Jeppsson says: "The take-off data computation was based on far too low a take-off weight. So that gave a very, very low V1, V2, and VR and when the rotation was performed it did not give the desired results. The aircraft over-rotated and there was a tailscrape although it turned out to be not bad enough to warrant changing the skid.
"The captain realised that something was wrong and told the co-pilot to lower the nose. All the indications told him to carry on, which is what they are told to do, but he realised something was wrong and he aborted the take-off."
Remarkably the aircraft suffered only a scraped tailskid and three of four tyres burst on the left main landing gear, requiring the tyres and brakes to be replaced. Jeppsson says some passengers did not immediately even realise anything was amiss.
The SAS captain explains that since implementing ACARS some six months ago, SAS' procedure on the 767 fleet is for one pilot to enter the data for the calculations into the flight management system datapage and for both pilots to verify the inputs and the results.
The data entered comprises the aircraft's actual gross weight as passed to the crew, the wind, temperature, altimeter setting and runway condition. That is transmitted via ACARS to SAS operations' department and, within about 20s, the calculated flap setting, full thrust, derated thrust if possible, and speeds are transmitted back and printed out in the cockpit.
Before the introduction of ACARS, the SAS 767 fleet was using hand-held "take-off calculators" in the cockpit to calculate the same data - a major advance on the paper charts used by airlines for decades.
The SAS captain says: "The charts gave us very exact but very conservative figures so the calculator was a great step forward and ACARS is even better. I don't think I would want to revert to the old system."
Because the old chart system required the use of very conservative assumptions it actually constrained the loads that aircraft could carry at marginal airports, meaning the switch to computed solutions had a direct effect on operating efficiency.
Both SAS officials confirm that, although the Swedish investigation authorities are examining what happened, there is no question that it was the crew that made the error and not the operations staff.
Jeppsson says: "As soon as we identify the weak area then my idea would be to immediately correct it. But we don’t want to change a procedure or anything like that until we know exactly what we want to do.
"We have sent a message to pilots to say that obviously this is a grey area to put it mildly. It seems like something very basic but clearly it can happen."
What is certain is that SAS would be extremely reluctant to reduce the use of ACARS itself - it has been a hugely enthusiastic user of the system and datalink programme manager, Bjorn Syren, publicly identified its role in take-off calculations as "a big success" at an ARINC symposium in May.
Source: Air Transport Intelligence news
Pilot error blamed for SIA's Auckland tailscrape
Nicholas Ionides, Singapore (16Dec03, 01:08 GMT, 525 words)
A severe tailscrape incident on takeoff involving a Singapore Airlines (SIA) Boeing 747-400 at Auckland International Airport in March was caused by basic crew errors that resulted in a slower-than-required rotation speed, according to New Zealand accident investigators.
New Zealand’s Transport Accident Investigation Commission (TAIC) says in its final report that a takeoff weight transcription error led to a miscalculation of the takeoff data, which resulted in a low thrust setting “and excessively slow takeoff reference speeds”.
It says the rotation speed had been mistakenly calculated for an aircraft weighing 100t less than the actual weight of the 747-400, which suffered substantial damage to its lower rear fuselage.
As a result the rotation speed was 33kt (61km/h) less than the 163kt (302km/h) that was required for the aircraft. When the captain rotated the aircraft for takeoff the tail struck the runway “and scraped for some 490m until the aeroplane became airborne”.
The TAIC says in its report that the 49-year-old captain, who has since left SIA, had 12,475hr of flying experience at the time but only 54hr on the 747-400, as he had just converted from the lighter Airbus A340-300.
One of two first officers on board had 223hr of flying time on the 747-400 and only 1,309hr in total. The other “was a qualified and very experienced first officer”, with around 3,386hr on the aircraft type.
None of the 369 passengers or 20 crewmembers on board the aircraft was injured. The ten-year-old 747-400, registered as 9V-SMT, was operating as flight SQ286 on 12 March 2003, bound for Singapore. The crew returned the aircraft to Auckland after takeoff and made a successful overweight emergency landing.
“The system defences did not ensure the errors were detected, and the aeroplane flight management system itself did not provide a final defence against mismatched information being programmed into it,” says the TAIC.
“During the takeoff the aeroplane moved close to the runway edge and the pilots did not respond correctly to a stall warning. Had the aeroplane moved off the runway or stalled a more serious accident could have occurred.”
It adds: “The aeroplane takeoff performance was degraded by the inappropriately low thrust and reference speed settings, which compromised the ability of the aeroplane to cope with an engine failure and hence compromised the safety of the aeroplane and its occupants.”
The TAIC says “safety recommendations addressing operating procedures and training” were made to SIA, while a recommendation concerning the flight management system was made to Boeing.
Star Alliance carrier SIA says in a statement that the TAIC’s safety recommendations “have been, or are being, implemented in full”, adding that it is “sorry that pilot error prior to the takeoff led to this aviation occurrence”.
“The emergency procedures followed by our pilots led to the aircraft returning to Auckland safely a short time later with no injuries to passengers or crew. The safe return is a reflection of the pilots’ training and good airmanship,” it says.
“We wish to assure our customers that the lessons from this occurrence and arising out of this thorough investigation by the TAIC have been learnt and several procedural changes have already been implemented.”
Source: Air Transport Intelligence news
Some posts above have suggested that an error in V speeds of sufficient magnitude to cause this accident was inconceivable. I'm not implying I have any insight into whether this was a factor at Madrid or not - but I do think these incidents make it clear that the notion is not out of the question.
Somebody out there may know whether the procedures/kit used by Spanair are the same as SAS, which I think is likely given their commercial/operational relationship. And you may have opinions on the subtle factors at play with the trend to uplinked weights and/or V speeds.
SAS probes procedures after close call on take-off
Kieran Daly, London (03Sep99, 12:16 GMT, 759 words)
SAS is reviewing its cockpit procedures after a Boeing 767 came close to catastrophe on take-off when the crew used the wrong aircraft weight for its performance calculations.
The captain of the Tokyo-bound 767-300ER aborted take-off at Copenhagen after rotation when he realised something was wrong and managed to stop inside the length of the airport's 3,570m (11,713ft) runway 22R from a speed of around 140kt (260km/hr).
The aircraft suffered a minor tailstrike and burst tyres and it has since been established that the crew had entered the aircraft's zero fuel weight (ZFW) instead of its gross weight - about a 65t difference.
SAS, which recently changed its procedure for calculating take-off speeds - switching from using a hand-held computer in the cockpit to the use of the ACARS (aircraft communications addressing and reporting system) datalink to have the final calculation performed elsewhere - is now trying to see if there is a way to reduce the chance of a repetition.
A senior Captain involved in the review tells ATI: "This happened to a very experienced professional colleague of mine. My first thought was that if this can happen to a solid fellow like this then it can happen to anyone. So we have to look into it and see what we can do."
Another SAS official - director of flight operations in Denmark, Fleming Jeppsson - relates how in the 24 August incident the co-pilot was conducting the take-off and rotated the aircraft at the calculated speed (VR).
Jeppsson says: "The take-off data computation was based on far too low a take-off weight. So that gave a very, very low V1, V2, and VR and when the rotation was performed it did not give the desired results. The aircraft over-rotated and there was a tailscrape although it turned out to be not bad enough to warrant changing the skid.
"The captain realised that something was wrong and told the co-pilot to lower the nose. All the indications told him to carry on, which is what they are told to do, but he realised something was wrong and he aborted the take-off."
Remarkably the aircraft suffered only a scraped tailskid and three of four tyres burst on the left main landing gear, requiring the tyres and brakes to be replaced. Jeppsson says some passengers did not immediately even realise anything was amiss.
The SAS captain explains that since implementing ACARS some six months ago, SAS' procedure on the 767 fleet is for one pilot to enter the data for the calculations into the flight management system datapage and for both pilots to verify the inputs and the results.
The data entered comprises the aircraft's actual gross weight as passed to the crew, the wind, temperature, altimeter setting and runway condition. That is transmitted via ACARS to SAS operations' department and, within about 20s, the calculated flap setting, full thrust, derated thrust if possible, and speeds are transmitted back and printed out in the cockpit.
Before the introduction of ACARS, the SAS 767 fleet was using hand-held "take-off calculators" in the cockpit to calculate the same data - a major advance on the paper charts used by airlines for decades.
The SAS captain says: "The charts gave us very exact but very conservative figures so the calculator was a great step forward and ACARS is even better. I don't think I would want to revert to the old system."
Because the old chart system required the use of very conservative assumptions it actually constrained the loads that aircraft could carry at marginal airports, meaning the switch to computed solutions had a direct effect on operating efficiency.
Both SAS officials confirm that, although the Swedish investigation authorities are examining what happened, there is no question that it was the crew that made the error and not the operations staff.
Jeppsson says: "As soon as we identify the weak area then my idea would be to immediately correct it. But we don’t want to change a procedure or anything like that until we know exactly what we want to do.
"We have sent a message to pilots to say that obviously this is a grey area to put it mildly. It seems like something very basic but clearly it can happen."
What is certain is that SAS would be extremely reluctant to reduce the use of ACARS itself - it has been a hugely enthusiastic user of the system and datalink programme manager, Bjorn Syren, publicly identified its role in take-off calculations as "a big success" at an ARINC symposium in May.
Source: Air Transport Intelligence news
Pilot error blamed for SIA's Auckland tailscrape
Nicholas Ionides, Singapore (16Dec03, 01:08 GMT, 525 words)
A severe tailscrape incident on takeoff involving a Singapore Airlines (SIA) Boeing 747-400 at Auckland International Airport in March was caused by basic crew errors that resulted in a slower-than-required rotation speed, according to New Zealand accident investigators.
New Zealand’s Transport Accident Investigation Commission (TAIC) says in its final report that a takeoff weight transcription error led to a miscalculation of the takeoff data, which resulted in a low thrust setting “and excessively slow takeoff reference speeds”.
It says the rotation speed had been mistakenly calculated for an aircraft weighing 100t less than the actual weight of the 747-400, which suffered substantial damage to its lower rear fuselage.
As a result the rotation speed was 33kt (61km/h) less than the 163kt (302km/h) that was required for the aircraft. When the captain rotated the aircraft for takeoff the tail struck the runway “and scraped for some 490m until the aeroplane became airborne”.
The TAIC says in its report that the 49-year-old captain, who has since left SIA, had 12,475hr of flying experience at the time but only 54hr on the 747-400, as he had just converted from the lighter Airbus A340-300.
One of two first officers on board had 223hr of flying time on the 747-400 and only 1,309hr in total. The other “was a qualified and very experienced first officer”, with around 3,386hr on the aircraft type.
None of the 369 passengers or 20 crewmembers on board the aircraft was injured. The ten-year-old 747-400, registered as 9V-SMT, was operating as flight SQ286 on 12 March 2003, bound for Singapore. The crew returned the aircraft to Auckland after takeoff and made a successful overweight emergency landing.
“The system defences did not ensure the errors were detected, and the aeroplane flight management system itself did not provide a final defence against mismatched information being programmed into it,” says the TAIC.
“During the takeoff the aeroplane moved close to the runway edge and the pilots did not respond correctly to a stall warning. Had the aeroplane moved off the runway or stalled a more serious accident could have occurred.”
It adds: “The aeroplane takeoff performance was degraded by the inappropriately low thrust and reference speed settings, which compromised the ability of the aeroplane to cope with an engine failure and hence compromised the safety of the aeroplane and its occupants.”
The TAIC says “safety recommendations addressing operating procedures and training” were made to SIA, while a recommendation concerning the flight management system was made to Boeing.
Star Alliance carrier SIA says in a statement that the TAIC’s safety recommendations “have been, or are being, implemented in full”, adding that it is “sorry that pilot error prior to the takeoff led to this aviation occurrence”.
“The emergency procedures followed by our pilots led to the aircraft returning to Auckland safely a short time later with no injuries to passengers or crew. The safe return is a reflection of the pilots’ training and good airmanship,” it says.
“We wish to assure our customers that the lessons from this occurrence and arising out of this thorough investigation by the TAIC have been learnt and several procedural changes have already been implemented.”
Source: Air Transport Intelligence news
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Originally Posted by Escubic
I have compensated the Telecinco photo of the groundtracks for perspective. The processing assumes a flat terrain.
Google Earth Community: Spanair flight JK 5022 accident in Madrid
I can be viewed in Google Earth (recommended) or Google Maps. Some resolution was lost in the process of creating the KMZ file.
Google Earth Community: Spanair flight JK 5022 accident in Madrid
I can be viewed in Google Earth (recommended) or Google Maps. Some resolution was lost in the process of creating the KMZ file.
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I wonder if the statements about a slow take-off roll can give any clues to the "wrong take-off configuration" hypothesis.
IF the flaps and slats were retracted, one would expect the acceleration to look normal (possibly even slightly better) until the airplane is rotated (at a speed below Vr for the no-flaps configuration). From there on the acceleration would suffer due to the nose-up angle and ensuing high drag, prolonging the long ground roll before finally becoming airborne (as it briefly did).
IF on the other hand the take-off configuration was okay and the airplane still had a longer than normal take-off roll, then it would point to a thrust deficit below commanded thrust, and the abnormally slow take-off roll would be apparent already before it rotated.
The question is then, did the witnesses comment on a slow take-off in the early stages of it, or only after rotation? Anyone seen such statements?
A sub-question for the second case: What faults would possibly cause a thrust decrease and still not show up on the engine instruments or alarms?
IF the flaps and slats were retracted, one would expect the acceleration to look normal (possibly even slightly better) until the airplane is rotated (at a speed below Vr for the no-flaps configuration). From there on the acceleration would suffer due to the nose-up angle and ensuing high drag, prolonging the long ground roll before finally becoming airborne (as it briefly did).
IF on the other hand the take-off configuration was okay and the airplane still had a longer than normal take-off roll, then it would point to a thrust deficit below commanded thrust, and the abnormally slow take-off roll would be apparent already before it rotated.
The question is then, did the witnesses comment on a slow take-off in the early stages of it, or only after rotation? Anyone seen such statements?
A sub-question for the second case: What faults would possibly cause a thrust decrease and still not show up on the engine instruments or alarms?
Plastic PPRuNer
"....since been established that the crew had entered the aircraft's zero fuel weight (ZFW) instead of its gross weight - about a 65t difference."
Are there not sanity checks in the ACARS?
Our software rejects things like 120% burns or 1 year old babies weighing 90kg as being impossible/unlikely.
Mac
Are there not sanity checks in the ACARS?
Our software rejects things like 120% burns or 1 year old babies weighing 90kg as being impossible/unlikely.
Mac
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Whilst the speculation simmers
Excuse me for hijacking whilst the speculation simmers...
If this was the case that one of the TRs was locked out (and I guess MEL'd)
then i find that incredible. I know this might p some people off on here,
but still, i saw someone comment well it's ok as both runways were long
enough not to require both TR's but what about in emergencies or diverting
to other runways. Or issues where they need to abort and stop in the
shortest time possible.
Ive maintained fire engines of various forms and never would i sign one off
with a SINGLE deffective brake or component.
Im shocked.
If this was the case that one of the TRs was locked out (and I guess MEL'd)
then i find that incredible. I know this might p some people off on here,
but still, i saw someone comment well it's ok as both runways were long
enough not to require both TR's but what about in emergencies or diverting
to other runways. Or issues where they need to abort and stop in the
shortest time possible.
Ive maintained fire engines of various forms and never would i sign one off
with a SINGLE deffective brake or component.
Im shocked.
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well it's ok as both runways were long enough not to require both TR's but what about in emergencies or diverting to other runways.
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"A symptomatic RAT probe and an airplane that doesnt know if its on the ground or in the air could easily lead to false EPR values and hence lower than indicated takeoff thrust.
Despite reaching vr it is possible the airplane had not sufficient thrust
to takeoff without stalling." (Jimclearsky)
Something like that has been suggested since very early posts, but I wonder why acknowledged people here haven't got deeper on it.
Besides, it's been said that a malfunction of the heater that caused the aircraft to return and the subsequent disconection of this device could possibly be explained because of the same type of failure. (No official version about this, I wonder if this possibility was checked at the return of the aircraft to apron).
Now, although I know very little about these devices, what's been said makes me think even more of this possibility.
Despite reaching vr it is possible the airplane had not sufficient thrust
to takeoff without stalling." (Jimclearsky)
Something like that has been suggested since very early posts, but I wonder why acknowledged people here haven't got deeper on it.
Besides, it's been said that a malfunction of the heater that caused the aircraft to return and the subsequent disconection of this device could possibly be explained because of the same type of failure. (No official version about this, I wonder if this possibility was checked at the return of the aircraft to apron).
Now, although I know very little about these devices, what's been said makes me think even more of this possibility.
Last edited by jacilore; 28th Aug 2008 at 12:28.
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Deferring the TRs is common practise on a lot of a/c types for whatever period of time (10 days in this case). Some types can still use the other one (thus asymetrical), some can´t.
(Dry) landing distances are always calculated without the use of TRs and factored by 1,67 for commercial operation. So the abscence of the TRs doesn´t necessarily pose a significant risk, especially in hot and dry Spain on long runways.
And remember that there are lots of a/c out there that come without TRs in the first place.
------------------------------------------------------------------------------------
Oh, I just see, I was too slow....
(Dry) landing distances are always calculated without the use of TRs and factored by 1,67 for commercial operation. So the abscence of the TRs doesn´t necessarily pose a significant risk, especially in hot and dry Spain on long runways.
And remember that there are lots of a/c out there that come without TRs in the first place.
------------------------------------------------------------------------------------
Oh, I just see, I was too slow....
Last edited by Avionero; 28th Aug 2008 at 12:37.
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Simple - really. All aircraft braking performance numbers are certified/predicted without reversers. If you've got them fine - if you haven't - also fine.
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Unfortunately I have not seen "first hand" the account of any witness mentioning exactly how long the take off seemed to them. Only the words of news reporters that have spoken to them. The ones that noticed the maneuver, said they felt "it took too long".
Putting it all together from the different sources, there is some evidence that: rolling on the ground took "a bit longer than usual" and nose angle of rotation was "weird".
But there is no statements I've found of how long each part of the process took.
Then again, since the security tape seems to only show the final 7-8 seconds of the take-off and no (reliable) direct witness I know of noticed precisely the whole maneuver (from the outside) and the survivors inside are naturally imprecise, I don't think we can know for sure.
But you can i.e. work on the scenario of slightly short calculations for weight/thrust. In that case, indeed the plane would have less air resistance than normal from the failure to lower the flaps (enough)/no slat, but also would accelerate a bit slower than "normal" as the thrust requested was a bit "understimated" for the weight. One effect might cancel the other and the length of strip used to VR may have seem "normal enough" to the crew.
Then you start rotation and the nose gets on a weird angle. The excess drag also makes it take longer to take-off. Thrust is on the low side of things. Air density is low. Tail wind. Nose angle steep-ish. No or insufficient flaps/slats.
They finally do take off, but rotation took significantly longer (total t/o maneuver took some estimated 500m more than it should've).
But they quickly (reportly some 3-4 seconds later), perhaps just out of ground-effect, find a wing stalling and roll to the left. From that point on the witnesses speak of a steep roll to the right and then fall.
We will have to wait for the FDR data as we are talking about not-extreme differences from normal expected performance and borderline out of specs. The crew may or may not have noticed well in advance enough what was happening before they had to struggle with uncomanded rolls and stall alarms.
Putting it all together from the different sources, there is some evidence that: rolling on the ground took "a bit longer than usual" and nose angle of rotation was "weird".
But there is no statements I've found of how long each part of the process took.
Then again, since the security tape seems to only show the final 7-8 seconds of the take-off and no (reliable) direct witness I know of noticed precisely the whole maneuver (from the outside) and the survivors inside are naturally imprecise, I don't think we can know for sure.
But you can i.e. work on the scenario of slightly short calculations for weight/thrust. In that case, indeed the plane would have less air resistance than normal from the failure to lower the flaps (enough)/no slat, but also would accelerate a bit slower than "normal" as the thrust requested was a bit "understimated" for the weight. One effect might cancel the other and the length of strip used to VR may have seem "normal enough" to the crew.
Then you start rotation and the nose gets on a weird angle. The excess drag also makes it take longer to take-off. Thrust is on the low side of things. Air density is low. Tail wind. Nose angle steep-ish. No or insufficient flaps/slats.
They finally do take off, but rotation took significantly longer (total t/o maneuver took some estimated 500m more than it should've).
But they quickly (reportly some 3-4 seconds later), perhaps just out of ground-effect, find a wing stalling and roll to the left. From that point on the witnesses speak of a steep roll to the right and then fall.
We will have to wait for the FDR data as we are talking about not-extreme differences from normal expected performance and borderline out of specs. The crew may or may not have noticed well in advance enough what was happening before they had to struggle with uncomanded rolls and stall alarms.
Last edited by justme69; 28th Aug 2008 at 13:18.
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Flaps.
Question for MD80 pilots. In the event of a flaps up take off, would there be a configuration warning to the crew on such an old aircraft? Rumours around Barajas and within JK are that they may have departed flaps up.
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i am really impressed by the amount of knowledge shown here and by how much useful discussion has been possible basing only on the little evidence available and with the tools in public domain like GE
my congratulations, gentlemen.
my congratulations, gentlemen.
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I am convinced that many people don't read anything prior to the last page or two.
THE MD80 has a takeoff configuration warning that would alert the pilots that the flaps/slats were not set for takeoff (among other things).
The age of the plane doesn't really matter here. The DC9, which the md80 is based upon, which has flown since the 1960's has a takeoff configuration warning system.
NOW, I published earlier how the RAT probe problem may have been a SYMPTOM of a problem indicating that the takeoff configuration warning system might be compromised.
I also indicated, many,many posts ago, that most pilots have learned by now that they should also check engine power/performance by using N1, and it should easily be in the 97percent to 99 percent range for takeoff. EPR, while interesting and important can be compromised rather easily.
THE MD80 has a takeoff configuration warning that would alert the pilots that the flaps/slats were not set for takeoff (among other things).
The age of the plane doesn't really matter here. The DC9, which the md80 is based upon, which has flown since the 1960's has a takeoff configuration warning system.
NOW, I published earlier how the RAT probe problem may have been a SYMPTOM of a problem indicating that the takeoff configuration warning system might be compromised.
I also indicated, many,many posts ago, that most pilots have learned by now that they should also check engine power/performance by using N1, and it should easily be in the 97percent to 99 percent range for takeoff. EPR, while interesting and important can be compromised rather easily.
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Question for MD80 pilots. In the event of a flaps up take off, would there be a configuration warning to the crew on such an old aircraft? Rumours around Barajas and within JK are that they may have departed flaps up.
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Spanair crash team focus on faulty thruster-papers
Reuters Thu Aug 28, 2008 6:53am EDT
... Air crash investigators were unavailable for comment on the reports as was engine-maker Pratt and Whitney, while Spanair, owned by Scandinavia's SAS airline, declined to comment.
Full report
Spanair crash team focus on faulty thruster-papers | Industries | Industrials, Materials & Utilities | Reuters20080828
http.. 3w.reuters.com/article/rbssIndustryMaterialsUtilitiesNews/idUSLS42830120080828
... Air crash investigators were unavailable for comment on the reports as was engine-maker Pratt and Whitney, while Spanair, owned by Scandinavia's SAS airline, declined to comment.
Full report
Spanair crash team focus on faulty thruster-papers | Industries | Industrials, Materials & Utilities | Reuters20080828
http.. 3w.reuters.com/article/rbssIndustryMaterialsUtilitiesNews/idUSLS42830120080828
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I want to ask an open question.
What happen if with correct flap config, trim, cg and engines, you select wrong V1/VR/V2 speeds, with values bellow the real ones?
What happen if with correct flap config, trim, cg and engines, you select wrong V1/VR/V2 speeds, with values bellow the real ones?
it ended up by large pieces of underfuselage near the tail being torn off on runway.the crews didn't realize the tailstrike, but understood something was wrong and release back pressure on the controls and aircraft smoothly took off and departed
after an in flight visual check performed by a figther 45 minutes later, the company decided to call back the plane that landed back two hours later
each of the crew had more than 10000 hours
PS : the flight has been reported at last minute the evening before due to technical problem and curfew time
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Apologies if THIS MD-80 accident has been mentioned before. Interesting reading. 3.5Meg pdf.
To do a 'Speed Read' type the word 'configuration' in the Find Box, top right.
Runway Over-run Onur Air. Runway overrun after rejected take-off of the Onur Air MD-88, registration TC-ONP, at Groningen Airport Eelde on 17 June 2003.
Synopsis. The investigation shows that the crew initially rejected the take-off when an acoustic alert signal was activated. This signal pertained to a warning for an incorrect setting of the trim of the longitudinal control system. When carrying out a check the crew did not find any peculiarities, although these were present. After this short interruption the take-off was resumed and this time, when the (repeating) sound alert signal went off, the signal was ignored.
When the captain noticed that the control force required to rotate the aircraft was significantly higher than normal he decided to reject the take-off. At that moment the remaining runway length was too short to bring the aircraft to a complete stop before the runway end.
To do a 'Speed Read' type the word 'configuration' in the Find Box, top right.
Runway Over-run Onur Air. Runway overrun after rejected take-off of the Onur Air MD-88, registration TC-ONP, at Groningen Airport Eelde on 17 June 2003.
Synopsis. The investigation shows that the crew initially rejected the take-off when an acoustic alert signal was activated. This signal pertained to a warning for an incorrect setting of the trim of the longitudinal control system. When carrying out a check the crew did not find any peculiarities, although these were present. After this short interruption the take-off was resumed and this time, when the (repeating) sound alert signal went off, the signal was ignored.
When the captain noticed that the control force required to rotate the aircraft was significantly higher than normal he decided to reject the take-off. At that moment the remaining runway length was too short to bring the aircraft to a complete stop before the runway end.