Spanair accident at Madrid
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Originally Posted by CLEE
I would say that you make everying flat as far as you can given the physical restraints imposed upon you. I appreciate that other airports have similar hazards too, and rather than that serve as an excuse for this accident, why can't this accident serve as a pointer to all those hazardous situations? If that means fixing Leeds-Bradford or the Bath Road, so be it (I'd like to see BAA's risk assesment for that).
In the case of MAD, it would take a LOT of landfill/earthworks to eliminate the drop, but is probably doable, in the case of LTN, a cut and cover tunnel could do (but I believe there's some significant roadworks already to improve access to LTN from the A505, trying to eliminate the roundabout for airport traffic).
But all the pontificating in the world (granted, I'm guilty of it) about what could/should be done won't mean a jot until we know why the jet went down.
S.
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In the link below there is a inphografy of accident with known actual data.
Press over "PULSE PARA CONTINUAR" below the MD-82 image and follow the sequence with indicators (arrows).
Gráficos en ELPAÍS.com
Press over "PULSE PARA CONTINUAR" below the MD-82 image and follow the sequence with indicators (arrows).
Gráficos en ELPAÍS.com
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pax wanted to get off the plane during repair prior to accident
Hi, this is my first post because I'm not a pro (I do have a PPL SEL). I do have a questions for the pros, though. According to Spanish TV, at least one passenger wanted to get off the plane while it was being repaired at the gate. Ruben Santana, one of the victims, is said to have sent an SMS to a family member prior to the accident saying he wanted to get off the plane and that his request was denied. Question: shy would such a request be denied if the plane is at the gate and there is plenty of time for the pax to get off? Who would it be up to to grant or deny such a request? Thanks.
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There are a lot of comments as to why the a/c wouldn't have enough power to get up after an engine failure.
Is there any proof this was a 'contained' failure?? The chances are the tail plane or rudder could have been severely damaged forcing the roll/pitch that caused the accident.
I am just speculating as much as everyone else...the fact of the matter is...god's wishes to everyone involved. Absolute tragic...
Is there any proof this was a 'contained' failure?? The chances are the tail plane or rudder could have been severely damaged forcing the roll/pitch that caused the accident.
I am just speculating as much as everyone else...the fact of the matter is...god's wishes to everyone involved. Absolute tragic...
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Thread Drift
Can I suggest that if we are about to review every airport in the world for an off runway excursion that we start a new thread please?
The thread is about an accident and thread 213 should be read by all. Page 11
For an off runway excursion, the answers are the same. You will hit another aircraft, a terminal, a motorway, the sea, an ILS array, a noise bund etc. Maybe even a tree or a Toyota Camry. In fact you can guarantee you will hit anything that is in the way...
Then there is also what is "in the way" on the approach and the climb if something goes wrong....BA 777?...and then the cruise. And then on route if we need somewhere to land because we can't make it to an airport.....to veer off the runway when we get there....
The aim of all in the industry should be that we put serviceable aircraft into the air and competent crew to get the aircraft out of trouble if luck is having a bad day. Sometimes with 100% planning things still go wrong.
The thread is about an accident and thread 213 should be read by all. Page 11
For an off runway excursion, the answers are the same. You will hit another aircraft, a terminal, a motorway, the sea, an ILS array, a noise bund etc. Maybe even a tree or a Toyota Camry. In fact you can guarantee you will hit anything that is in the way...
Then there is also what is "in the way" on the approach and the climb if something goes wrong....BA 777?...and then the cruise. And then on route if we need somewhere to land because we can't make it to an airport.....to veer off the runway when we get there....
The aim of all in the industry should be that we put serviceable aircraft into the air and competent crew to get the aircraft out of trouble if luck is having a bad day. Sometimes with 100% planning things still go wrong.
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PSZ is always measured form each depatrure end of the runway. It is a permanent designation at eaither end of each runway. Smaller airports ( less volume of flights) have a triangle with base 230m either side of centreline coming to an apex at 2.3km.
The ravine is outwith what would be a CAA designated PSZ ( public safety zone) but within Airport perimeter - no access to Public. ThPSZ is designed to identify areas of risk ,for departing and, I assume, arriving Aircraft. Within the bouandary there are inherent risks around the airfield - these whoule be assessed and mitigation measures employed to reduce or remove the risk
My point was that if the MD 80 left LHR 09L and followed the same path it would end up in the BMi Hangar!
The ravine is outwith what would be a CAA designated PSZ ( public safety zone) but within Airport perimeter - no access to Public. ThPSZ is designed to identify areas of risk ,for departing and, I assume, arriving Aircraft. Within the bouandary there are inherent risks around the airfield - these whoule be assessed and mitigation measures employed to reduce or remove the risk
My point was that if the MD 80 left LHR 09L and followed the same path it would end up in the BMi Hangar!
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xcoote:
6. A quick shove of the autothrottles would have given them emergency power (or even more) if needed as the MD-82 has conventional (auto)throttles.
6. A quick shove of the autothrottles would have given them emergency power (or even more) if needed as the MD-82 has conventional (auto)throttles.
Could someone with more MD knowledge than me confirm or deny that?
Much appreciated.
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I might have missed something in more recent posts, but I think I read earlier that if the engine temperature probe was MEL for that flight, then autothrottles would be considered unserviceable and would have to be disabled
6. A quick shove of the autothrottles would have given them emergency power (or even more) if needed
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My point was that if the MD 80 left LHR 09L and followed the same path it would end up in the BMi Hangar!
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Probably the idea is not "all land should be flat" but more like "the fire trucks should be able to reach any point within airport, except inside buildings"? and probably add "in five minutes or less"?
Why is airport design not allowed in this discussion. At this moment nobody on this thread knows the exact trajectory of the aircraft. It might well be an important factor in the accident investigation.
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The thread is about an accident
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Originally Posted by NigelOnDraft
Quote:
6. A quick shove of the autothrottles would have given them emergency power (or even more) if needed
Originally Posted by MD80 Flight Manual, Windshear recovery
If flight path control becomes marginal at low altitude, initiate the windshear recovery maneuver without delay. If ground contact appears imminent, either pilot calls “MAX THROTTLE.” Accomplish the first three steps simultaneously:
[...]
2. Aggressively apply maximum thrust [...]. To ensure maximum thrust is obtained with minimum delay, an overshoot to the mechanical stops is recommended until positive indications of recovery are confirmed
Bernd
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Bad summary, I know, but we are all speculating, which is not necessarily bad
I'm not an expert. Obviously there are many facts about this accident we don't know and won't for while. I'm not a native English speaker (spanish). I would like to summarize some of the facts as I have been able to find through media reports in Spain and the more credible of internet rumors (witnesses with videos/photos posted, i.e.).
-According to official statement from the company as well as witnesses reports (passengers phoned/texted on cell phones to relatives about the delay and the "cause" as explained to them), a first attempt to take off was very early (during taxing probably) aborted by the pilot due to a "malfunction indicator" (vague red light). The pilot explained the passengers it was a "heat sensor" (ambigous) and returned to the terminal to have it "repaired". The repairs were limited to disabling it (tripped-off) within about 1 hour. PAX remained on board all this time. The company confirms that some indicator relative to outside air temperature showed "overheat status" (ambigous) and was disabled as described above. Exact nature not fully explained. It would be good if someone with knowledge explained exactly what this is and how it could've affected the accident. It seems that a probe for outside air temperature is located inside an opening-tube near the cabin in the front of the airplane. Such device has a heating system to prevent ice from blocking the air-intake. The sensor for overheating in this device seems to have turned-on for unknown reasons (speculative, exact malfuntion indicated by the alarm probe not clear). Not clear whether only the sensor was de-activated or the whole device was turned off (on purpose or by mistake). Not clear if this would mean a lack of reliable automatic measure of outside air temperature. Not clear if this would mean that automated or assisted take-off systems that may have relayed on this information for take-off would function properly (assuming whole device and not just the probe was disabled "by mistake" or malfunction, ie). Not clear if the pilots would be aware that a fully manual take-off procedure was needed in that case, if at all applicable. Etc, etc.
-The pilot and maintenance technician agreed on a fit-to-fly status and geared for take-off. At this point of the investigation, this problem is not primarely considered by any parties involved part of the accident, but of course it's being investigated.
-The airplane reached V1 without any reliable sources claiming any potential problems (no pilot communications I heard of, no reliable witnesses reported). The fly was presumably at full weight capacity, perhaps even exceeding it a bit (fueled for the 2.40m flight, full PAX capacity, extra crew, holliday destination, Spanair is routinely forgiving of a few extra pounds of excess luggage, MAD-LPA is a VERY cargo-intensive route). Some sources say perhaps it was a little slow to reach VR, consuming more airstrip than usual, but possibly within reason. Obviously it had to be somewhat of a tight take-off.
-The airplane reached VR and take-off was inminent. Perhaps VR calculations weren't right, but we can assume a competent and experienced crew in a clear scenario they knew very well in good weather and plenty of available airstrip.
-The front landing gear is CONFIRMED to have left the ground. This has been confirmed by the sources consulted by the newspapers in Spain that cited sources in the investigation with access to the Aena Barajas Airport security cameras footage. The minister in Spain also confirmed on Tv appearance this as well as added "and probably also the back wheels (left the ground)".
-Most sources say that indeed both set of wheels left the ground and the airplane flew for a few seconds while ascending. One unconfirmed source cites a nearby pilot witness noticing a "strange nose angle" (ambigous).
*At this point, I think it's safe to assume that, unless the crew was wayyy off, the airplane was thought to have enough thrust and speed to carry on the take-off. A lot of airfield, well in excess of 1km, seems to have been still available at this point should they have noticed a lack of engine power or other unusual activity.
-For reasons unknown yet, the airplane abruptly descended again, possibly after some unsuall roll. First RUMORS spoke of a catastrophic external left engine failure. This has mostly been dismissed as no credible direct witness speaks of that and it doesn't show on the Aena video. One perhaps credible source citing a nearby pilot witness speaks of a flash on one engine, compatible with events such as a bird crash or perhaps even an engine stall or catastrophic contained malfunction, but not full-blow explosion, nor engine detachement, nor full-out-fire. Air density was low as was wind. I haven't seen a report on the extend of flap deployment.
*One of the most likely causes of the plane going back down to ground at this point would indeed need to be either a very badly calculated VR speed coupled with thrust problems ending in early and sudden stall or a very sudden loss of symetrical engine power coupled with not-the-best-of-the-best crew response. Scenarios such as a single engine reverse deployment would put the flyability seriously in danger too at that or near that point. Such accidental reverse deployment could've happened at exactly V1 or little after while there was still weight on the wheels, i.e. Purely especulative on my side.
-The airplane "hit the ground". Some witnesses described it as "bounced up and down several times" as it was "breaking down in pieces" and finally crashed. Oficials say "one of the wings touched the ground" and it bounced. Clear landing marks on the runaway show that the landing gear was still deployed and the airplane "hard landed", possibly with the brakes on, on all three sets of wheels, and after a short straight run it veired somewhat hard (right?) all the way out of the landing strip, when still close to 1km of runaway paviment was available on it.
-The airplane "lost control", possible suffered some landing gear or other damages when it hit the grouind (being fully loaded, it probably exceeded landing weight specs), kept rolling on the ground to the side of the airstrip until it hit enviromental obstacles at high speed a few hundred meters later, creating a ball of fire that dragged several tens of meters according to credible witnesses (nearby airport worker who shot video right after this). It completely broke into many pieces, with hardly any structure remaining intact at all, specially after the fire, fueled furhter by dry vegetation. Biggest pieces left seem to have been the very end of the tail and the engines. Some witnesses spoke of "broke-in-half", "broke-in-three-pieces", "completely broke into hundreds of pieces". Debri expanded over 400m area. Speed must have been pretty high considering it was probably brakeing.
-Survivors account the event as: "we heard a loud noise, the plane started to move from 'side to side' (ambigous) and then crashed". The most credible survivor doesn't remember the exact moment of the crash, but soon before and soon thereafter.
-A photo of the wreckage seems to show one of the engine with the thrust reverser engaged and locked, indicating either an attempted abort during take-off (or forced landing, depending on how you look at it, as it seems to have happened seconds after airbone).
As it stands, speculating as we all are trying to find some thruth facts that could be of help, I think hardly any scenario can be dismissed at this point. It could still be:
-Human error. Reverser could've been somehow deployed (unlikely), VR badly calculated (unlikely), speed-thrust a bit too low coupled with some other problem (perhaps), "voluntary" attempted TO abort after VR, etc.
-Mechanical error. Engine failure coupled with "bad luck" (i.e. wing hitting the ground before crew could recover from loss of thrust, affecting control). Control system malfunction resulting in the always dangerous decission to abort after VR (if they thought they couldn't control the airplane, they had no choice but to try to abort). A photo show some unusual damage to the tail structure, but way too early to make a call.
-Any other factor that made the pilot either lose control or decide to abort after VR. Credible reports mention the airplane banking and a wing touching the ground before-or-while attempting to "land" or perhaps just as it left the ground.
-The flight recorders have been retrieved although the telemetry one is damaged.
Please note that "landing" and "take-off" in this incident are blurred terms as the accident seems to have been a product of something that happened almost inmediately after the wheels left the ground that ultimately made the airplane touch the ground again very soon thereafter and somewhat lose control.
Sorry again for posting a non-expert (at all) speculative account. Just trying to help and perhaps I'm not, but I honesly hope I am not adding senseless noise to clear-headed truth seekers. Sorry for my bad english.
Condolences to the families and friends of the sadly deceased. Hopefully you'll find some confort on knowing, one day, the reasons this accident ocurred.
-According to official statement from the company as well as witnesses reports (passengers phoned/texted on cell phones to relatives about the delay and the "cause" as explained to them), a first attempt to take off was very early (during taxing probably) aborted by the pilot due to a "malfunction indicator" (vague red light). The pilot explained the passengers it was a "heat sensor" (ambigous) and returned to the terminal to have it "repaired". The repairs were limited to disabling it (tripped-off) within about 1 hour. PAX remained on board all this time. The company confirms that some indicator relative to outside air temperature showed "overheat status" (ambigous) and was disabled as described above. Exact nature not fully explained. It would be good if someone with knowledge explained exactly what this is and how it could've affected the accident. It seems that a probe for outside air temperature is located inside an opening-tube near the cabin in the front of the airplane. Such device has a heating system to prevent ice from blocking the air-intake. The sensor for overheating in this device seems to have turned-on for unknown reasons (speculative, exact malfuntion indicated by the alarm probe not clear). Not clear whether only the sensor was de-activated or the whole device was turned off (on purpose or by mistake). Not clear if this would mean a lack of reliable automatic measure of outside air temperature. Not clear if this would mean that automated or assisted take-off systems that may have relayed on this information for take-off would function properly (assuming whole device and not just the probe was disabled "by mistake" or malfunction, ie). Not clear if the pilots would be aware that a fully manual take-off procedure was needed in that case, if at all applicable. Etc, etc.
-The pilot and maintenance technician agreed on a fit-to-fly status and geared for take-off. At this point of the investigation, this problem is not primarely considered by any parties involved part of the accident, but of course it's being investigated.
-The airplane reached V1 without any reliable sources claiming any potential problems (no pilot communications I heard of, no reliable witnesses reported). The fly was presumably at full weight capacity, perhaps even exceeding it a bit (fueled for the 2.40m flight, full PAX capacity, extra crew, holliday destination, Spanair is routinely forgiving of a few extra pounds of excess luggage, MAD-LPA is a VERY cargo-intensive route). Some sources say perhaps it was a little slow to reach VR, consuming more airstrip than usual, but possibly within reason. Obviously it had to be somewhat of a tight take-off.
-The airplane reached VR and take-off was inminent. Perhaps VR calculations weren't right, but we can assume a competent and experienced crew in a clear scenario they knew very well in good weather and plenty of available airstrip.
-The front landing gear is CONFIRMED to have left the ground. This has been confirmed by the sources consulted by the newspapers in Spain that cited sources in the investigation with access to the Aena Barajas Airport security cameras footage. The minister in Spain also confirmed on Tv appearance this as well as added "and probably also the back wheels (left the ground)".
-Most sources say that indeed both set of wheels left the ground and the airplane flew for a few seconds while ascending. One unconfirmed source cites a nearby pilot witness noticing a "strange nose angle" (ambigous).
*At this point, I think it's safe to assume that, unless the crew was wayyy off, the airplane was thought to have enough thrust and speed to carry on the take-off. A lot of airfield, well in excess of 1km, seems to have been still available at this point should they have noticed a lack of engine power or other unusual activity.
-For reasons unknown yet, the airplane abruptly descended again, possibly after some unsuall roll. First RUMORS spoke of a catastrophic external left engine failure. This has mostly been dismissed as no credible direct witness speaks of that and it doesn't show on the Aena video. One perhaps credible source citing a nearby pilot witness speaks of a flash on one engine, compatible with events such as a bird crash or perhaps even an engine stall or catastrophic contained malfunction, but not full-blow explosion, nor engine detachement, nor full-out-fire. Air density was low as was wind. I haven't seen a report on the extend of flap deployment.
*One of the most likely causes of the plane going back down to ground at this point would indeed need to be either a very badly calculated VR speed coupled with thrust problems ending in early and sudden stall or a very sudden loss of symetrical engine power coupled with not-the-best-of-the-best crew response. Scenarios such as a single engine reverse deployment would put the flyability seriously in danger too at that or near that point. Such accidental reverse deployment could've happened at exactly V1 or little after while there was still weight on the wheels, i.e. Purely especulative on my side.
-The airplane "hit the ground". Some witnesses described it as "bounced up and down several times" as it was "breaking down in pieces" and finally crashed. Oficials say "one of the wings touched the ground" and it bounced. Clear landing marks on the runaway show that the landing gear was still deployed and the airplane "hard landed", possibly with the brakes on, on all three sets of wheels, and after a short straight run it veired somewhat hard (right?) all the way out of the landing strip, when still close to 1km of runaway paviment was available on it.
-The airplane "lost control", possible suffered some landing gear or other damages when it hit the grouind (being fully loaded, it probably exceeded landing weight specs), kept rolling on the ground to the side of the airstrip until it hit enviromental obstacles at high speed a few hundred meters later, creating a ball of fire that dragged several tens of meters according to credible witnesses (nearby airport worker who shot video right after this). It completely broke into many pieces, with hardly any structure remaining intact at all, specially after the fire, fueled furhter by dry vegetation. Biggest pieces left seem to have been the very end of the tail and the engines. Some witnesses spoke of "broke-in-half", "broke-in-three-pieces", "completely broke into hundreds of pieces". Debri expanded over 400m area. Speed must have been pretty high considering it was probably brakeing.
-Survivors account the event as: "we heard a loud noise, the plane started to move from 'side to side' (ambigous) and then crashed". The most credible survivor doesn't remember the exact moment of the crash, but soon before and soon thereafter.
-A photo of the wreckage seems to show one of the engine with the thrust reverser engaged and locked, indicating either an attempted abort during take-off (or forced landing, depending on how you look at it, as it seems to have happened seconds after airbone).
As it stands, speculating as we all are trying to find some thruth facts that could be of help, I think hardly any scenario can be dismissed at this point. It could still be:
-Human error. Reverser could've been somehow deployed (unlikely), VR badly calculated (unlikely), speed-thrust a bit too low coupled with some other problem (perhaps), "voluntary" attempted TO abort after VR, etc.
-Mechanical error. Engine failure coupled with "bad luck" (i.e. wing hitting the ground before crew could recover from loss of thrust, affecting control). Control system malfunction resulting in the always dangerous decission to abort after VR (if they thought they couldn't control the airplane, they had no choice but to try to abort). A photo show some unusual damage to the tail structure, but way too early to make a call.
-Any other factor that made the pilot either lose control or decide to abort after VR. Credible reports mention the airplane banking and a wing touching the ground before-or-while attempting to "land" or perhaps just as it left the ground.
-The flight recorders have been retrieved although the telemetry one is damaged.
Please note that "landing" and "take-off" in this incident are blurred terms as the accident seems to have been a product of something that happened almost inmediately after the wheels left the ground that ultimately made the airplane touch the ground again very soon thereafter and somewhat lose control.
Sorry again for posting a non-expert (at all) speculative account. Just trying to help and perhaps I'm not, but I honesly hope I am not adding senseless noise to clear-headed truth seekers. Sorry for my bad english.
Condolences to the families and friends of the sadly deceased. Hopefully you'll find some confort on knowing, one day, the reasons this accident ocurred.
Last edited by justme69; 22nd Aug 2008 at 20:19.
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Amount of rudder during failed engine / high yaw
May I add to posts in the 200s referring to rudder inputs, as there were some questions:
Every aircraft has a rudder built in size and aerodynamic force adequate to stop the yaw induced by engine failure. On a B747 it is a lot larger than on the B737 due to the long arm force of the outboard engines, it could cover a one-side dual flameout (NOT discussing the performance capabilities at high GW here, only the induced yaw by failed engines on one side and max power on the other).
Otherwise, no commercial jet aircraft would be certified to operate if this was not possible.
The rudder on any commercial jet aircraft will be designed to cover this well, that means not by using maximum input, but rather large input under adverse conditions.
Not all too much larger. Much more may overstress the structure and would be absolutely fatal, if a pilot used full input on an overdimensioned rudder in a one-sided loss of thrust condition to recover from the yaw. It would rip off the tail section (New York A300 crash 2001 after encountering wake vortices and overcontrolling by rudder Yo-Yo). The B737 for example has a rudder pressure reducer to inhibit application of maximum rudder (for example by false hydraulic system behaviour), unless engine failure occurs at low altitudes (overriding the RPR system enabling full rudder).
Referring to previous writers, ANY aircraft would require almost full rudder input on an engine failure at takeoff (relatively low speed = low aerodynamic rudder effect) with full takeoff thrust on the opposite side in adverse conditions (worst: low gross weight meaning less speed, high takeoff power at low temperatures, like in a high obstacle climbout).
The rudder of the MD80 is of RATHER small dimension compared to wing-mounted engine aircrafts, for the reasons mentioned above, but sized sufficiently to recover from an engine failure under adverse conditions.
Every aircraft has a rudder built in size and aerodynamic force adequate to stop the yaw induced by engine failure. On a B747 it is a lot larger than on the B737 due to the long arm force of the outboard engines, it could cover a one-side dual flameout (NOT discussing the performance capabilities at high GW here, only the induced yaw by failed engines on one side and max power on the other).
Otherwise, no commercial jet aircraft would be certified to operate if this was not possible.
The rudder on any commercial jet aircraft will be designed to cover this well, that means not by using maximum input, but rather large input under adverse conditions.
Not all too much larger. Much more may overstress the structure and would be absolutely fatal, if a pilot used full input on an overdimensioned rudder in a one-sided loss of thrust condition to recover from the yaw. It would rip off the tail section (New York A300 crash 2001 after encountering wake vortices and overcontrolling by rudder Yo-Yo). The B737 for example has a rudder pressure reducer to inhibit application of maximum rudder (for example by false hydraulic system behaviour), unless engine failure occurs at low altitudes (overriding the RPR system enabling full rudder).
Referring to previous writers, ANY aircraft would require almost full rudder input on an engine failure at takeoff (relatively low speed = low aerodynamic rudder effect) with full takeoff thrust on the opposite side in adverse conditions (worst: low gross weight meaning less speed, high takeoff power at low temperatures, like in a high obstacle climbout).
The rudder of the MD80 is of RATHER small dimension compared to wing-mounted engine aircrafts, for the reasons mentioned above, but sized sufficiently to recover from an engine failure under adverse conditions.
Last edited by parthura; 22nd Aug 2008 at 21:06.
bsieker
Here's an excellent chance for you to learn something and perhaps to share it with the rest of the forum
Do a google search on MD80 reserve thrust (excluding all flight sim products).
This neat little feature doesn't need pilot input, it simply looks for differences between engines of 10% or so.
I'm not sure about the term, either, but the MD80's JT8D-200 engines, being mechanically controlled (non-FADEC), can deliver more than maximum rated thrust, if needed. This is called "MAX THROTTLE", and should be limited to stall and wind shear recovery at low altitudes; a normal go-around should not require more than maximum rated thrust.
Do a google search on MD80 reserve thrust (excluding all flight sim products).
This neat little feature doesn't need pilot input, it simply looks for differences between engines of 10% or so.