Spanair accident at Madrid
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Apologies if this is the dumbest of dumb suggestions, but is there any possibility that the straight track, which we're speculating might have been made by the nose gear, could actually have been made by the tail?
It looks as if the track starts at a point roughly level with the tail cone, and it's parallel to the eventual track of the main gear, as if the tail hit just as the aircraft was steering to port. Is it possible that this was the tail strike that's been mentioned?
Of course, the track is well off-centre, which suggest that I'm wildly wrong, or the tail section had partly broken off by that point and was dragging on the left, or perhaps was subject to that weird geometry we've been looking at.
And given the foreshortened perspective, it could be that my theory makes the plane half a mile long! It's just an idea.
It looks as if the track starts at a point roughly level with the tail cone, and it's parallel to the eventual track of the main gear, as if the tail hit just as the aircraft was steering to port. Is it possible that this was the tail strike that's been mentioned?
Of course, the track is well off-centre, which suggest that I'm wildly wrong, or the tail section had partly broken off by that point and was dragging on the left, or perhaps was subject to that weird geometry we've been looking at.
And given the foreshortened perspective, it could be that my theory makes the plane half a mile long! It's just an idea.
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I don´t think that this is possible. The tail is a lot closer to the main gear, so the plane would have to drift a LOT more than if it had been the nose wheel (what we also don´t know for sure). So the 7° mentioned before for the nose wheel would be some 30°-40° for the tail (just a wild guess), which would bring the main gear tracks closer together.
I tend to think that the straight line stems from the nose wheel, what is not completely consistent with that however is, that a drift of the airframe should bring the main wheel tracks closer together (which might be lost in the angle of the photo).
I tend to think that the straight line stems from the nose wheel, what is not completely consistent with that however is, that a drift of the airframe should bring the main wheel tracks closer together (which might be lost in the angle of the photo).
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Jacilore, I think your diagram is wrong. The well-defined triangle is made by all the gear hitting the ground at the start of the three heavy black lines, the skid marks.
The straight black line is the nosewheel and the two twin curving skid marks are the main gear. The nosewheel track is straight and the main gear drifts first left and then right.
See xkoote’s illustration in Post 1023.
The straight black line is the nosewheel and the two twin curving skid marks are the main gear. The nosewheel track is straight and the main gear drifts first left and then right.
See xkoote’s illustration in Post 1023.
There are several rows of tracks parallel to the runway -- likely a tractor pulling a mower.
And other tracks indicative of the tractor coming back to resume where it had left off.
The nosewheel while attached will likely leave a track less distinct that that from a tractor.
And other tracks indicative of the tractor coming back to resume where it had left off.
The nosewheel while attached will likely leave a track less distinct that that from a tractor.
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207 kph & Inop Reverser
Telecinco reports the investigation is centering on why the aircraft failed to reach the necessary 210 kph for takeoff, reaching only 207 kph. The recovered deployed reverser was activated by the pilot, but the right side reverser could not be deployed as it had been deactivated since August 17. The pilot attempted to brake using the pedals and deployed reverse thrust.
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27.08.08 | 15:11 h. INFORMATIVOS TELECINCO
Según la última línea de investigación, el avión no alcanzó la velocidad necesaria para elevarse. La aeronave no llegó a despegar al no acelerar lo suficiente y terminó dando tumbos por la pista. La comisión de investigación centra todos sus esfuerzos en determinar por qué la velocidad no llegó a los 210 kilómetros por hora necesarios para despegar y se quedó en los 207 kilómetros. Informativos Telecinco también ha podido saber que la reversa derecha del avión estaba bloqueada desde el día 17 de agosto.
El MD- 82 recorrió la pista con aparente normalidad pero no alcanzó la velocidad necesaria para despegar. A unos metros de la pista se aprecia en la fotografía el cono de la cola entre otras piezas del avión. Una parte del motor también se desprendió en el intento de despegue.
Una de las piezas encontradas tras el siniestro fue una reversa desplegada. Ese freno fue activado por el piloto, pero la reversa derecha no pudo ser desplegada por un fallo registrado en una revisión habitual el día 17 de agosto que había impedido activarla, por lo que fue bloqueada ese mismo día. Según la normativa vigente, un avión puede volar de forma normal sólo con una reversa y si otra es bloqueada, puede hacerlo durante diez días (habría estado permitido hasta el día 27 de agosto).
Según ha podido saber Informativos Telecinco, la Comisión de investigación centra sus esfuerzos en determinar por qué el avión no alcanzó la velocidad adecuada. El piloto intentó frenar con los pedales y luego con las reversas.
-------------
27.08.08 | 15:11 h. INFORMATIVOS TELECINCO
Según la última línea de investigación, el avión no alcanzó la velocidad necesaria para elevarse. La aeronave no llegó a despegar al no acelerar lo suficiente y terminó dando tumbos por la pista. La comisión de investigación centra todos sus esfuerzos en determinar por qué la velocidad no llegó a los 210 kilómetros por hora necesarios para despegar y se quedó en los 207 kilómetros. Informativos Telecinco también ha podido saber que la reversa derecha del avión estaba bloqueada desde el día 17 de agosto.
El MD- 82 recorrió la pista con aparente normalidad pero no alcanzó la velocidad necesaria para despegar. A unos metros de la pista se aprecia en la fotografía el cono de la cola entre otras piezas del avión. Una parte del motor también se desprendió en el intento de despegue.
Una de las piezas encontradas tras el siniestro fue una reversa desplegada. Ese freno fue activado por el piloto, pero la reversa derecha no pudo ser desplegada por un fallo registrado en una revisión habitual el día 17 de agosto que había impedido activarla, por lo que fue bloqueada ese mismo día. Según la normativa vigente, un avión puede volar de forma normal sólo con una reversa y si otra es bloqueada, puede hacerlo durante diez días (habría estado permitido hasta el día 27 de agosto).
Según ha podido saber Informativos Telecinco, la Comisión de investigación centra sus esfuerzos en determinar por qué el avión no alcanzó la velocidad adecuada. El piloto intentó frenar con los pedales y luego con las reversas.
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Catplaystation (and others)
It's human nature to be curious. Otherwise we would never learn anything new. Man would never have invented the aircraft.
I suspect a majority of "speculators" here have technical backgrounds.
We are educated to solve technical problems given to us whatever facts we are
presented with. Speculations and theory's are part of the learning process and
isolating the problem. Call it brain exercise, it's healthy - even to pilots - ask your doctor
XPM
This thread has been a pain in the proverbial for some time, with the usual wild uninformed speculation taking up pages and pages
I suspect a majority of "speculators" here have technical backgrounds.
We are educated to solve technical problems given to us whatever facts we are
presented with. Speculations and theory's are part of the learning process and
isolating the problem. Call it brain exercise, it's healthy - even to pilots - ask your doctor
XPM
Cleverly disguised as a responsible adult
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The nosewheel while attached will likely leave a track less distinct that that from a tractor.
Axle weight 60/3 = 20 tonne
Weight of tractor possibly 2 tonne
Axle weight 2/2 =1 tonne
So a possible 20 (10 tonne per wheel) tonne weight will leave less distinct mark than 1 tonne (1/2 tonne per wheel)?
I accept that the weight balance of an aircraft will lead to differing weights to the above but cannot accept that the nose wheels would have a low figure (otherwise the nose would be bouncing into the air)
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One more question to pilots of similar airplanes. Assuming a fairly normal looking take-off, but one that took some "500m more than usual" to be accomplished like reported (we are unsure if fully on the ground or extra long rotation)...
Is this compatible with assymetrical accidental reverser deployment?
-If such thing happened say right after or inmediately before V2, it wouldn't explain the long time it took to (theoretically) accelerate on the ground to reach V2, right?
-If such thing happened after V1 (so crew had to choose the option to continue) but before VR (or around at that time), wouldn't normally the crew had realised something was seriously wrong and either try to abort or have time to compensate (given the long runaway) plus wouldn't the airplane tend to move left or right while still on the ground, or not necessarily? Also, would the survivors or the crew notice clearly some sudden decceleration or forces to one side necessarily, or not? Would they notice something incompatible with "normal feeling take-off, going up, some vibration, rolling to one side, rolling steeply to the other, crashing"?
Thanks.
Another survivor has left the hospital. 14 remain. 2 remain in very serious condition.
Is this compatible with assymetrical accidental reverser deployment?
-If such thing happened say right after or inmediately before V2, it wouldn't explain the long time it took to (theoretically) accelerate on the ground to reach V2, right?
-If such thing happened after V1 (so crew had to choose the option to continue) but before VR (or around at that time), wouldn't normally the crew had realised something was seriously wrong and either try to abort or have time to compensate (given the long runaway) plus wouldn't the airplane tend to move left or right while still on the ground, or not necessarily? Also, would the survivors or the crew notice clearly some sudden decceleration or forces to one side necessarily, or not? Would they notice something incompatible with "normal feeling take-off, going up, some vibration, rolling to one side, rolling steeply to the other, crashing"?
Thanks.
Another survivor has left the hospital. 14 remain. 2 remain in very serious condition.
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Accidental thrust reverser deployment now ruled out
Thrust setting not sufficient. Again, pulled RAM probe heater CB part of the picture?
210 kph is only 113 kts. That is certainly not the required VR or V2. Somebody may have mixed up knots and miles when converting?
Telecinco reports the investigation is centering on why the aircraft failed to reach the necessary 210 kph for takeoff, reaching only 207 kph. The recovered deployed reverser was activated by the pilot, but the right side reverser could not be deployed as it had been deactivated since August 17. The pilot attempted to brake using the pedals and deployed reverse thrust.
210 kph is only 113 kts. That is certainly not the required VR or V2. Somebody may have mixed up knots and miles when converting?
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Could it be possible that the pilot selected reverse after the a/c was back on the ground in an attempt to stop? would be a logical explanation to find the reverser out of stowed position in the wreckage......
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justme69
errr.... abort after V1 
It is of course possible that a crew might elect to abort after V1, however, it would be such an exceptional circumstance or error that I do not think it worth speculating on without concrete evidence that it occurred
NoD
If such thing happened after V1 (so crew had to choose the option to continue) but before VR (or around at that time), wouldn't normally the crew had realised something was seriously wrong and either try to abort
It is of course possible that a crew might elect to abort after V1, however, it would be such an exceptional circumstance or error that I do not think it worth speculating on without concrete evidence that it occurred
NoD
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thank you theron, been wandering about that when the first stories about the thrust reverser popped up...... the answer posted 9 minutes earlier.. hope the answers from the fdr and cvr will shed a light on what did happen... anybody info of the type of fdr/cvr installed in md82 a/c (digital/analoge, amount of parameters monitored etc.)?
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Telecinco groundtrack photo for Google Earth processed
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.
Last edited by Escubic; 27th Aug 2008 at 21:28.
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A couple of points about these marks in the grass:
The straight track seems v. unlikely to be the nosegear. Even if we accept that it's possible for a nosegear track to deviate outside the track of the mains, it would surely be miraculous for it to be dead straight while the mains are carving an S turn with no sign of sideways skidding. Much more likely to me is something breaking free and continuing in a straight line.
The straight track, on the aircraft's right at this point, starts at the same point as the first deviation to the right. Can we postulate a single cause for both? For example (pure guess) the right thrust reverser deploying on command and the ground ripping off the lower part of the reverser?
[Caveat - no professional knowledge influences the above!]
The straight track seems v. unlikely to be the nosegear. Even if we accept that it's possible for a nosegear track to deviate outside the track of the mains, it would surely be miraculous for it to be dead straight while the mains are carving an S turn with no sign of sideways skidding. Much more likely to me is something breaking free and continuing in a straight line.
The straight track, on the aircraft's right at this point, starts at the same point as the first deviation to the right. Can we postulate a single cause for both? For example (pure guess) the right thrust reverser deploying on command and the ground ripping off the lower part of the reverser?
[Caveat - no professional knowledge influences the above!]
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The weights and proportion per gear are measured at "rest". An airplane traveling at > 130 knots and bouncing along....the actual weight and proportion per gear is more determined by the flight controls and terrain.
Interesting is a plane that is 85% flying....and would leave such dark/deep tracks in hard and dry ground. Is this what it would look like if spoilers were out and ground brakes locked?
Interesting is a plane that is 85% flying....and would leave such dark/deep tracks in hard and dry ground. Is this what it would look like if spoilers were out and ground brakes locked?
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I just wonder about the very regular look of the marks. Having in mind that the airplane was struggling for (direction) control I would not expect such linear traces without indication of sideway skidding or changing pressure onto the ground.
How can one explain that?
How can one explain that?
Last edited by Flyer94; 27th Aug 2008 at 21:49.