Spanair accident at Madrid
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Thanks, doodahdave, for that very clear explanation.
Just69... Many thanks for the info. To my knowledge, this is the first instance that a Spanish newspaper clearly states that the flaps were not deployed on takeoff. I've not been able to find the Spanish text in the webpage of 'El Periodico de Aragon'. Could you please supply a reference?
XXXavier
Just69... Many thanks for the info. To my knowledge, this is the first instance that a Spanish newspaper clearly states that the flaps were not deployed on takeoff. I've not been able to find the Spanish text in the webpage of 'El Periodico de Aragon'. Could you please supply a reference?
XXXavier
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Autothrottles or manual?
If the RAT was indicating 99 C, then the Thrust Rating Computer was getting inaccurate information.
And if the RAT was high, then the TRI would set the EPR Takeoff Limit artificially low.
When the RAT is inoperative, our MEL specifies that Autothrottles must also be placarded inoperative. Only manual thrust for takeoff.
If we leave with an inoperative RAT, then we must use SAT via the PMS or GFMS or FMS to set climb limit thrust limits.
Dave
And if the RAT was high, then the TRI would set the EPR Takeoff Limit artificially low.
When the RAT is inoperative, our MEL specifies that Autothrottles must also be placarded inoperative. Only manual thrust for takeoff.
If we leave with an inoperative RAT, then we must use SAT via the PMS or GFMS or FMS to set climb limit thrust limits.
Dave
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Borgha
No, from the info available at the moment, not ''deep stall'. That is a particular phenomenon of T-tailed aircraft fully in flight.
Not to go into technicalities, but the bird in question was supposedly barely off the ground (in ground effect type flight)
Not to go into technicalities, but the bird in question was supposedly barely off the ground (in ground effect type flight)
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Just69... Many thanks for the info. To my knowledge, this is the first instance that a Spanish newspaper clearly states that the flaps were not deployed on takeoff. I've not been able to find the Spanish text in the webpage of 'El Periodico de Aragon'. Could you please supply a reference?
Dispositivos replegados - Sociedad - www.elperiodicodearagon.com
For a google automatic translation to english, you may click this link below
Versión traducida de http://www.elperiodicodearagon.com/noticias/noticia.asp?pkid=440235
A reporter from that newspaper openly and publicly claims to have a copy of the Aena video and that he has personally inspected it frame by frame.
Sorry there are hardly any more new details or that most of the ones showing up lately only repeat what it has pretty much been established already. At least the "new sources" are not contradicting some of the important details (so far) and seem to corroborate them.
One last note: the CVR recording does show the sound of several impacts, which one can assume are from the fall and hits on the ground, and seems to have continued recording all the way to the final crash (as we know, some 1.5km away from the first contact with the ground).
Last edited by justme69; 13th Sep 2008 at 18:43.
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MD80 slat system...
doodahdave, very good description of the system!
I flew the DC9/MD80 series aircraft for 16 years, and I have the same positive impression of the system - safe, simple and reliable. No failures except the odd Auto Slat failure, as doodahdave mentions may happen.
To the best of my knowledge the failure reported in post #1671 is of this category - and it is NO factor in the accident.
doodahdave, agree?
I flew the DC9/MD80 series aircraft for 16 years, and I have the same positive impression of the system - safe, simple and reliable. No failures except the odd Auto Slat failure, as doodahdave mentions may happen.
To the best of my knowledge the failure reported in post #1671 is of this category - and it is NO factor in the accident.
doodahdave, agree?
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Autoslat failure?
grebllaw123d
Thanks for the feedback. All I can say is that I learned from some of the best pilots in the industry! I use what they taught me every day.
And yes, I agree. It appears that the Autoslat failure previously noted in the logbook is not related to the accident.
borghha
Althought I don't ever remember seeing any "Dial-a-Flap" settings of less than 4 degrees for takeoff on the MD80, I'd bet that with both engines operating, a successful takeoff could be made with the slats in partial extension or mid-seal. I remember a rough estimate of 40 knot reduction in stall speed with slat extension on the MD80.
Slat-only takeoffs were routine on the DC9-50 series when operating from hot and high airports like Denver or Colorado Springs.
Dave
Thanks for the feedback. All I can say is that I learned from some of the best pilots in the industry! I use what they taught me every day.
And yes, I agree. It appears that the Autoslat failure previously noted in the logbook is not related to the accident.
borghha
Althought I don't ever remember seeing any "Dial-a-Flap" settings of less than 4 degrees for takeoff on the MD80, I'd bet that with both engines operating, a successful takeoff could be made with the slats in partial extension or mid-seal. I remember a rough estimate of 40 knot reduction in stall speed with slat extension on the MD80.
Slat-only takeoffs were routine on the DC9-50 series when operating from hot and high airports like Denver or Colorado Springs.
Dave
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Maintenance actions to resolve RAT problem leaded to inhibite take-off flaps alarm, and to put the aircraft in (electrical) flight conditions.
doodahdave,
Can you give us your analysis of posts 1489 and 1500?
Is this c/b thats mentioned routinely pulled by maint to check strobes for first flight of the day check?Is this your experience?This aircraft was on its second flight,having arrived from BCN.If the daily checks been done in BCN(Spanair base?),why pull this breaker in MAD?Is it possible they flew with it pulled from BCN or will the RAT probe overheat whatever the ambient conditions?BCN am departure=temp 15/59 vs. pm departure MAD=temp 30/86??
Autoslats only work with flaps/slats set ie slats already mid-seal..they re-position slats from mid-seal to full extend.Pls confirm.Is a slats only takeoff possible on this bird or just the DC9?How much stall speed margin does full extend from mid-seal buy you?Im just thinking of something to try to explain the awkward CVR leak that has the pilot saying Flaps/slats SET.A flapless takeoff combined with autoslat failure and incorrect TO thrust might be a way to explain the call and the accident.If flapless takeoff is not possible,then the call must have been rote or the leak is incorrect...
With RAT probe disabled,pls confirm that AT cannot be engaged(contrary to MEL)?TCI requires a temp input,even an invalid one,to function.Can it be pilot-entered?
Thanks.
Last edited by Rananim; 14th Sep 2008 at 01:31.
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Ranamin, you are right, I wrote it the wrong way round. Apologizes.
"The RAT probe failure was caused by the aircraft being in air mode in the first place."
Then the CWAS could not function properly, which is a NOGO.
The RAT probe failure analysis made by maint was not good.
Only my opinion.
"The RAT probe failure was caused by the aircraft being in air mode in the first place."
Then the CWAS could not function properly, which is a NOGO.
The RAT probe failure analysis made by maint was not good.
Only my opinion.
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Lets look at the no flap/slat scenario.
The given TOW is 64.263 kg. Lets assume they were
planning a F15 takeoff.
- The clean acf will stall at 166 kts
- A slat only will stall at 131 kts
- A slat/F15 acf will stall at 123 kts.
So obviously, the slats are the main contributers of lift on the MD80
in takeoff config. No slat will set you back 35 kts, no flap
will set you back only 8 kts.
Assuming they had slat but no flap, they would be 11 kts ABOVE
stall speed at Vr, so I think we can rule out this scenario since
the acf would most likely be flyable.
Assuming they were clean and went for F15 takeoff speeds,
at rotate Vr, they would have been 24 kts below stall speed, at V2
they would be 17 kts BELOW stall speed.
So the million $ questions are
1. Were the SLATS exended?
2. Would a clean MD80 be able to accelerate from Vr 142
to Vclean/stall 166 at a high AoA possibly scraping the tail
in a distance of about 500m?
XPM
The given TOW is 64.263 kg. Lets assume they were
planning a F15 takeoff.
- The clean acf will stall at 166 kts
- A slat only will stall at 131 kts
- A slat/F15 acf will stall at 123 kts.
So obviously, the slats are the main contributers of lift on the MD80
in takeoff config. No slat will set you back 35 kts, no flap
will set you back only 8 kts.
Assuming they had slat but no flap, they would be 11 kts ABOVE
stall speed at Vr, so I think we can rule out this scenario since
the acf would most likely be flyable.
Assuming they were clean and went for F15 takeoff speeds,
at rotate Vr, they would have been 24 kts below stall speed, at V2
they would be 17 kts BELOW stall speed.
So the million $ questions are
1. Were the SLATS exended?
2. Would a clean MD80 be able to accelerate from Vr 142
to Vclean/stall 166 at a high AoA possibly scraping the tail
in a distance of about 500m?
XPM
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XPMorten,
Thank you for that.The figures point convincingly at the clean scenario but then we have to reconcile this with the CVR leak....if he really did say SET to the FLAPS/SLATS challenge,then it was a rote response which puts the accident in a different category to Michigan where the checklist was omitted altogether.
Rote response in a checklist?It can happen of course.But to the most important challenge of the most important checklist?Thats hard to believe which makes me wonder about the authenticity of the CVR leak.
Thank you for that.The figures point convincingly at the clean scenario but then we have to reconcile this with the CVR leak....if he really did say SET to the FLAPS/SLATS challenge,then it was a rote response which puts the accident in a different category to Michigan where the checklist was omitted altogether.
Rote response in a checklist?It can happen of course.But to the most important challenge of the most important checklist?Thats hard to believe which makes me wonder about the authenticity of the CVR leak.
Last edited by Rananim; 14th Sep 2008 at 14:31.
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As a summary on this aspect:
The observed flight (takeoff) path and behaviour seem now to be looking very much like a slat-less take-off, which is somewhat more important than flap-less, albeit they often go together unless 2nd-segement climb performance becomes critical...
Slats provide ability to attain higher incidence whilst maintaining unstalled flow; flaps provide greater lift without necessity for higher incidence (reduce zero-lift incidence)...
Reported high aircraft incidence at rotation, subsequent loss of lift, including wing-dropping and loss of directional control are all very much pointing at slat-less and (now reported from one source) flap-less take-off.
Tragically, this very same situation seems to have taken place 2 years ago on the same type in the Canary Islands, but with just sufficient margins to allow 'hedge-hopping' flight until acceleration above safe flight speed for that configuration was achieved.
Take-off configuration warning systems designed and in-place to prevent this possibility may not have been working or compromised, in both cases.
The observed flight (takeoff) path and behaviour seem now to be looking very much like a slat-less take-off, which is somewhat more important than flap-less, albeit they often go together unless 2nd-segement climb performance becomes critical...
Slats provide ability to attain higher incidence whilst maintaining unstalled flow; flaps provide greater lift without necessity for higher incidence (reduce zero-lift incidence)...
Reported high aircraft incidence at rotation, subsequent loss of lift, including wing-dropping and loss of directional control are all very much pointing at slat-less and (now reported from one source) flap-less take-off.
Tragically, this very same situation seems to have taken place 2 years ago on the same type in the Canary Islands, but with just sufficient margins to allow 'hedge-hopping' flight until acceleration above safe flight speed for that configuration was achieved.
Take-off configuration warning systems designed and in-place to prevent this possibility may not have been working or compromised, in both cases.
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Didn't a LAPA 3142 flight (a 737 in that case) also crashed when it attempted to take off w/o flaps/slats? In that case, I think, the configuration alarms sounded, but the pilots neither aborted the take off nor figured out to deploy them on time (or couldn't, for whatever reason).
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Far fetched speculations
..Just for the record. VERY unlikely theoretical reason
why the flaps might have been found in the "up" position.
1. They got retracted at touchdown e.g. got accidentally hit by the F/O
on hard impact.
2. Flap/slat only got deployed one ONE WING.. .
This might explain the wing drop and significant right turn.
Also this might explain a no config warning situation... .
XPM
why the flaps might have been found in the "up" position.
1. They got retracted at touchdown e.g. got accidentally hit by the F/O
on hard impact.
2. Flap/slat only got deployed one ONE WING.. .
This might explain the wing drop and significant right turn.
Also this might explain a no config warning situation... .
XPM
...which puts the accident in a different category to Dallas and Michigan where the checklist was omitted altogether
The FO in Dallas replied 15 15 green green to the checklist.
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LAPA 3142
CVR. 31:37 - Cop.: "Rotate." 31:39 - Cop.: "V 2." 31:41 - 31:45 - Continuous mechanical sound of the stick shaker.
So where does the 737 get 'airborne' (WOW) signal from?
as the plane never took off.
So where does the 737 get 'airborne' (WOW) signal from?
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LAPA 3142
Quote:
as the plane never took off.
CVR. 31:37 - Cop.: "Rotate." 31:39 - Cop.: "V 2." 31:41 - 31:45 - Continuous mechanical sound of the stick shaker.
So where does the 737 get 'airborne' (WOW) signal from?
Quote:
as the plane never took off.
CVR. 31:37 - Cop.: "Rotate." 31:39 - Cop.: "V 2." 31:41 - 31:45 - Continuous mechanical sound of the stick shaker.
So where does the 737 get 'airborne' (WOW) signal from?
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2. Flap/slat only got deployed one ONE WING.. .
This might explain the wing drop and significant right turn.
Also this might explain a no config warning situation... .
This might explain the wing drop and significant right turn.
Also this might explain a no config warning situation... .
Green-dot