Continental TurboProp crash inbound for Buffalo
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I wonder what's included in that calculation.
My employer does...
Three weeks classroom: 15 days @ 8h = 120h
11 simulator sessions (incl. CPT) @ 4h = 44h
Perhaps include Sim Briefings/Debriefings: 10 @ 2.5h = 25h
Line training: minimum 40 sectors @ at least 1h = 40h
Total 'formal training' here is well over 200h.
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At 26t landing mass, VREF would be 121kt for a Flap 15 landing.
That is hardly relavent though, with Flap 5 selected on approach the minimum speed is 147kt (VREF137+10), or 157kt with the INCR REF Sw. selected ON. These are UK speeds, v slightly different in N.America.
My employer does...
Three weeks classroom: 15 days @ 8h = 120h
11 simulator sessions (incl. CPT) @ 4h = 44h
Perhaps include Sim Briefings/Debriefings: 10 @ 2.5h = 25h
Line training: minimum 40 sectors @ at least 1h = 40h
Total 'formal training' here is well over 200h.
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At 26t landing mass, VREF would be 121kt for a Flap 15 landing.
That is hardly relavent though, with Flap 5 selected on approach the minimum speed is 147kt (VREF137+10), or 157kt with the INCR REF Sw. selected ON. These are UK speeds, v slightly different in N.America.
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As a new member in this forum it has been very interesting to follow this thread. As a former Q400 pilot this accident has really caught my mind.
I share the view with a lot of you guys that the icing does not appear to be the obvious reason. I would like to share the following thoughts:
The configuration before selecting gear down and flaps 15 is normally flaps 5, at 25t this gives a Vsr (stall reference) of 110 kts in non-icing cond and 102 kts at flaps 10 which I understand is where the flaps got before selecting flaps 10 again.
Given the additional 20 kts margin added by the SPMs when ref speed is on it makes sense that the shaker activated in the 130 kts region.
A normal reaction at when this happens would be to initiate a go-around which according to SOP is full-power/flaps 10 and at positive climb rate gear-up. A two-engine Q400 go-around requires quite a lot of pitch up to avoid flap overspeed and to stay close to V2.
An abruptly performed go-around would increase the AoA and could in this case trigger the pusher.
The Operators Manual which I assume follows bombardiers input has a little bit different wordings on stall-recovery and windshear recovery. Stall recovery is basically a go-around proc with level pitch while windshear has the wordings:
Increase the pitch attitude by rotating the aircraft smoothly and steadily to achieve V2.
Simultaneously, select go around, disengaging the autopilot and if required, advance power
levers to the mechanical stops to arrest descent.
Trade speed for improved climb capability in order to prevent further altitude loss.
Do not accelerate back to final approach speed.
The stick shaker may activate at pitch attitudes lower than normal.
Pitch attitude must be reduced just enough to silence the shaker.
Note that this escape procedure promotes pitch attitudes limited by stick-shaker instead of re-gaining airspeed.
Another thing that comes to my mind is that even though 134kts in flaps 5 configuration is a anormally low operating speed it is still equal to Vref flaps 5 non-icing. Personally I agree that some kind of distraction caused this, I still think it is of interest to note that the speed bugs are set manually and that even though I put increase ref-speed on I can faulty set the bugs for non-icing. The bugs for 25t non-icing would be set at Vref = 119kts and Vfto = 146.
I share the view with a lot of you guys that the icing does not appear to be the obvious reason. I would like to share the following thoughts:
The configuration before selecting gear down and flaps 15 is normally flaps 5, at 25t this gives a Vsr (stall reference) of 110 kts in non-icing cond and 102 kts at flaps 10 which I understand is where the flaps got before selecting flaps 10 again.
Given the additional 20 kts margin added by the SPMs when ref speed is on it makes sense that the shaker activated in the 130 kts region.
A normal reaction at when this happens would be to initiate a go-around which according to SOP is full-power/flaps 10 and at positive climb rate gear-up. A two-engine Q400 go-around requires quite a lot of pitch up to avoid flap overspeed and to stay close to V2.
An abruptly performed go-around would increase the AoA and could in this case trigger the pusher.
The Operators Manual which I assume follows bombardiers input has a little bit different wordings on stall-recovery and windshear recovery. Stall recovery is basically a go-around proc with level pitch while windshear has the wordings:
Increase the pitch attitude by rotating the aircraft smoothly and steadily to achieve V2.
Simultaneously, select go around, disengaging the autopilot and if required, advance power
levers to the mechanical stops to arrest descent.
Trade speed for improved climb capability in order to prevent further altitude loss.
Do not accelerate back to final approach speed.
The stick shaker may activate at pitch attitudes lower than normal.
Pitch attitude must be reduced just enough to silence the shaker.
Note that this escape procedure promotes pitch attitudes limited by stick-shaker instead of re-gaining airspeed.
Another thing that comes to my mind is that even though 134kts in flaps 5 configuration is a anormally low operating speed it is still equal to Vref flaps 5 non-icing. Personally I agree that some kind of distraction caused this, I still think it is of interest to note that the speed bugs are set manually and that even though I put increase ref-speed on I can faulty set the bugs for non-icing. The bugs for 25t non-icing would be set at Vref = 119kts and Vfto = 146.
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Hello again.
I was the one who posted first about the voice of the readback, I did not want to imply anything, only if anyone else heard the same.
I am posting again regarding post Nş699.
First, once I had an anomaly with the AFCS in an ATR; we where vectored in VMC and we had the LOC captured but below the GS, because ATC were letting another traffic depart from the opposite rwy and they calculate that we will cross below them, and just when the traffic was about 3/4 of a mile in front of us and about 500 feet above and climbing, (we where at a level altitude) the copilot, PF, engage the GS that was more than 2 dots up, and surprise! the AFCS capture it with the follow pitch up, about 10ş, it produced a RA in the TCAS; so a pitch up could happen but 30ş or more I think that the logics of the AP forbid it.
Second, from some posts now, it is written that the SP activated and the AP disengage, and then the pitch up occured, so if this events happened in this secuence, the AP was off at the pitch up and this theory does not apply.
I was the one who posted first about the voice of the readback, I did not want to imply anything, only if anyone else heard the same.
I am posting again regarding post Nş699.
First, once I had an anomaly with the AFCS in an ATR; we where vectored in VMC and we had the LOC captured but below the GS, because ATC were letting another traffic depart from the opposite rwy and they calculate that we will cross below them, and just when the traffic was about 3/4 of a mile in front of us and about 500 feet above and climbing, (we where at a level altitude) the copilot, PF, engage the GS that was more than 2 dots up, and surprise! the AFCS capture it with the follow pitch up, about 10ş, it produced a RA in the TCAS; so a pitch up could happen but 30ş or more I think that the logics of the AP forbid it.
Second, from some posts now, it is written that the SP activated and the AP disengage, and then the pitch up occured, so if this events happened in this secuence, the AP was off at the pitch up and this theory does not apply.
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MicroCruzer,
Hello and welcome,
You state that the normal configuration before extending gear is flaps 5 - however at least it appears from below quote that flaps were selected from 0 to 15 after gear was extended.
In their Monday press conference the NTSB said, that the NTSB computes the gross weight at the time of the accident at 55000lbs. The crew intended to land with flaps 15, setting of choice. The Vref for that speed is 119 KIAS, with the reference speed increase switch activated it would be 139 KIAS. The airplane was doing 134 KIAS before lowering the gear and flaps. The NTSB however cautions before jumping to conclusions about the speeds at this stage, the speeds need further analysis before they can "be taken to the bank".
your comments?
brgds
You state that the normal configuration before extending gear is flaps 5 - however at least it appears from below quote that flaps were selected from 0 to 15 after gear was extended.
In their Monday press conference the NTSB said, that the NTSB computes the gross weight at the time of the accident at 55000lbs. The crew intended to land with flaps 15, setting of choice. The Vref for that speed is 119 KIAS, with the reference speed increase switch activated it would be 139 KIAS. The airplane was doing 134 KIAS before lowering the gear and flaps. The NTSB however cautions before jumping to conclusions about the speeds at this stage, the speeds need further analysis before they can "be taken to the bank".
your comments?
brgds
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It's interesting reading the comments regarding the benefits of autothrottle, and it would be easy to be left with the impression that this sytem has no 'gotchas' at all.
Wrong. Very wrong.
Whilst autothrottle is indeed a marvellous addition to an automated a/c, bear in mind that all it does is set sufficient thrust to maintain/achieve a bugged airspeed. It will do that whether or not this bugged speed is appropriate for the configuration of the a/c or not. For example, in flying an approach, bugged speed is reduced to a speed appropriate for a selection of flap, but flap is not selected. The autothrottle will still give you this bugged speed even though it may now be below that of the minimum manoeuvring speed for the current (incorrect) configuration.
In other words, if the bugged speed is wrong, then effectively you're in just as dangerous a situation as if you had no autothrottle in the first place. Add to the mix that autothrottle is primarily a jet accessory, and you potentially have a situation even more tricky to recover from than if you were flying a regional turboprop.
For as long as any automated system relies on inputs and monitoring from a fundamentally unreliable and fallible human machine, then there is no perfect system. You can talk about rules, regulations, SOPs, training, monitoring, concentration and all these other good things until you are blue in the face, but the simple fact is that people make mistakes, and they always will. You will only ever reduce the likelihood it will happen, but never eliminate it.
Wrong. Very wrong.
Whilst autothrottle is indeed a marvellous addition to an automated a/c, bear in mind that all it does is set sufficient thrust to maintain/achieve a bugged airspeed. It will do that whether or not this bugged speed is appropriate for the configuration of the a/c or not. For example, in flying an approach, bugged speed is reduced to a speed appropriate for a selection of flap, but flap is not selected. The autothrottle will still give you this bugged speed even though it may now be below that of the minimum manoeuvring speed for the current (incorrect) configuration.
In other words, if the bugged speed is wrong, then effectively you're in just as dangerous a situation as if you had no autothrottle in the first place. Add to the mix that autothrottle is primarily a jet accessory, and you potentially have a situation even more tricky to recover from than if you were flying a regional turboprop.
For as long as any automated system relies on inputs and monitoring from a fundamentally unreliable and fallible human machine, then there is no perfect system. You can talk about rules, regulations, SOPs, training, monitoring, concentration and all these other good things until you are blue in the face, but the simple fact is that people make mistakes, and they always will. You will only ever reduce the likelihood it will happen, but never eliminate it.
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Ref 699
Interesting to read (699) about a recommended change in SOP - i.e. to not arm APP until LOC established. That has been SOP at my airline for a long time, probably due to someone learning the hard way as usual...... My plane will certainly intercept a G/S signal, good or bad, if I arm APP, which in my bird (757) arms LOC and G/S capture. One can intercept G/S prior to LOC capture which is a big no-no. It is required that I be fully locked onto the LOC, and meeting altitude restrictions on the approach plate, before I select APP (G/S) to capture the correct G/S at the appropriate intercept altitude. I have seen crews arm G/S way too early, and either having to reset everything (you have to turn F/D's and A/P (if used) off to get out of APP mode if engaged) because of a false G/S intercept, or descend too early going into places with long final approaches, busting altitude restrictions depicted on the approach plate. They ignore the fact that there is a published G/S intercept altitude on the approach plate. G/S capture will always fly you away from your altitude, up or down - not good.
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grebllaw123d thanks for the welcome!
Regarding the statement about when the gear and flaps where extended. My take on this is that they could refer to before the gear down and flaps 15 were selected (as this was the last selection before the go-around setting). This could still be a valid statement even though the flaps before wasn't 0. If it was a gear down selecton from flaps 0 that would be atypical procedure mostly used for speed-braking purposes and that does not seem to be the case. The fact that they are selecting gear and flaps 15 on what looks like "on schedule" indicates that they are not aware that they are low on speed.
Regarding the statement about when the gear and flaps where extended. My take on this is that they could refer to before the gear down and flaps 15 were selected (as this was the last selection before the go-around setting). This could still be a valid statement even though the flaps before wasn't 0. If it was a gear down selecton from flaps 0 that would be atypical procedure mostly used for speed-braking purposes and that does not seem to be the case. The fact that they are selecting gear and flaps 15 on what looks like "on schedule" indicates that they are not aware that they are low on speed.
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Otto wrote:
"Whilst autothrottle is indeed a marvelous addition to an automated a/c, bear in mind that all it does is set sufficient thrust to maintain/achieve a bugged airspeed. It will do that whether or not this bugged speed is appropriate for the configuration of the a/c or not. For example, in flying an approach, bugged speed is reduced to a speed appropriate for a selection of flap, but flap is not selected. The autothrottle will still give you this bugged speed even though it may now be below that of the minimum maneuvering speed for the current (incorrect) configuration."
I have had the pleasure of operating aircraft with a couple of different autothrottle systems. Both systems incorporated flight envelope protection that would prevent the aircraft from flying below Vma or exceed Vmo/Mmo, gear and flap speed for the current configuration. If you bug a speed below Vma the autothrottle will command a speed equal too or 5 knots above Vma. On one of the types I operated the autothrottle would even reengage if it wasn't on if approaching Vma as long as the computers weren/t turned off, and would take into account the rate of acceleration/deceleration.
I find the comment about the aircraft being trimmend fully or close to fully nose up upon autopilot disengagement interesting. If the aircraft decelerated in level flight to 134kts at flaps zero there must have been considerable nose up trim? Besides it was the gear selected down at 134kts and flaps not selected until 20 seconds later, so assuming they did not touch the powerlevers the speed would have been well below 134kts when flaps 15 was finally selected.
There seem to be some confusion as far as the sequence of events, but NTSB states clearly in one of their reports that the shaker and pusher activated followed by autopilot disengagement.
From NTSB report:
"One minute prior to the end of the recording the airplane was travelling at a calibrated airspeed of 134 knots, the gear was selected down, 20 seconds later the flaps were selected to 15 degrees. The flaps reached 10 degrees 20 seconds later (and 20 seconds prior to the end of the recording), at which point the upset started. The stick shaker and stick pusher activated (at which point the autopilot would be disconnect at the very latest), then the airplane pitched up to 31 degrees nose up, then pitched down to 45 degrees nose down and rolled left to a bank angle of 46 degrees, then right to a bank angle of 105 degrees (already 15 degrees upside down). The airplane experienced G-forces between 0.75 and 2G. The crew applied full thrust with the begin of the upset 20 seconds prior to the end of recording. The flaps never went beyond 10 degrees."
"Whilst autothrottle is indeed a marvelous addition to an automated a/c, bear in mind that all it does is set sufficient thrust to maintain/achieve a bugged airspeed. It will do that whether or not this bugged speed is appropriate for the configuration of the a/c or not. For example, in flying an approach, bugged speed is reduced to a speed appropriate for a selection of flap, but flap is not selected. The autothrottle will still give you this bugged speed even though it may now be below that of the minimum maneuvering speed for the current (incorrect) configuration."
I have had the pleasure of operating aircraft with a couple of different autothrottle systems. Both systems incorporated flight envelope protection that would prevent the aircraft from flying below Vma or exceed Vmo/Mmo, gear and flap speed for the current configuration. If you bug a speed below Vma the autothrottle will command a speed equal too or 5 knots above Vma. On one of the types I operated the autothrottle would even reengage if it wasn't on if approaching Vma as long as the computers weren/t turned off, and would take into account the rate of acceleration/deceleration.
I find the comment about the aircraft being trimmend fully or close to fully nose up upon autopilot disengagement interesting. If the aircraft decelerated in level flight to 134kts at flaps zero there must have been considerable nose up trim? Besides it was the gear selected down at 134kts and flaps not selected until 20 seconds later, so assuming they did not touch the powerlevers the speed would have been well below 134kts when flaps 15 was finally selected.
There seem to be some confusion as far as the sequence of events, but NTSB states clearly in one of their reports that the shaker and pusher activated followed by autopilot disengagement.
From NTSB report:
"One minute prior to the end of the recording the airplane was travelling at a calibrated airspeed of 134 knots, the gear was selected down, 20 seconds later the flaps were selected to 15 degrees. The flaps reached 10 degrees 20 seconds later (and 20 seconds prior to the end of the recording), at which point the upset started. The stick shaker and stick pusher activated (at which point the autopilot would be disconnect at the very latest), then the airplane pitched up to 31 degrees nose up, then pitched down to 45 degrees nose down and rolled left to a bank angle of 46 degrees, then right to a bank angle of 105 degrees (already 15 degrees upside down). The airplane experienced G-forces between 0.75 and 2G. The crew applied full thrust with the begin of the upset 20 seconds prior to the end of recording. The flaps never went beyond 10 degrees."
Last edited by Rubberbiscuit; 19th Feb 2009 at 13:11. Reason: Content
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Quote:
what I believe was reported by the NTSB: severe pitch and roll as a result of flap deploy.
-- Very well,
pardon me. "after". The word "result" was presumptuous.
But how does this change the point I was trying to make?
Why would the airplane experience pitch and roll upset "after" flap deploy?
what I believe was reported by the NTSB: severe pitch and roll as a result of flap deploy.
Wrong! That's what the mediapersons wrote. What the NTSB said is that attitude excursions started after flaps being selected, not because of flaps extension. Post hoc ergo propter hoc strikes again.
pardon me. "after". The word "result" was presumptuous.
But how does this change the point I was trying to make?
Why would the airplane experience pitch and roll upset "after" flap deploy?
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The aircraft probably experienced pitch and roll upset due to factors unrelated to the flaps selection or deployment.
I believe the most likely cause is incorrect flight control inputs by the pilots following a stall warning/stick shaker/stick push scenario. This all happened simply because proper flying speed was not maintained.
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a question for Q drivers
If the sequence of events was indeed that first the gear was lowered and then 15 degrees flap was selected, what does this mean regarding the crew's awareness of the speed they were flying at?
What are gear limiting speed as well as flap 5 and 15?
Depending on your replies, it suggests to me the crew were aware that their speed was low enough for both gear and 15 flap, therefore suggesting they had checked their speed and therefore they had a reason to fly slowly.
No accusations intended, just wrecking my brain,,,,,
If the sequence of events was indeed that first the gear was lowered and then 15 degrees flap was selected, what does this mean regarding the crew's awareness of the speed they were flying at?
What are gear limiting speed as well as flap 5 and 15?
Depending on your replies, it suggests to me the crew were aware that their speed was low enough for both gear and 15 flap, therefore suggesting they had checked their speed and therefore they had a reason to fly slowly.
No accusations intended, just wrecking my brain,,,,,
Gender Faculty Specialist
The Gear limiting speed is 200kts operating and 215kts extended.
Flap 5 - 200kts, Flap 10 - 181kts, Flap 15 - 172kts.
Like I've said before our SOP was Flap 5, then the gear then the other stages of flap.
Flap 5 - 200kts, Flap 10 - 181kts, Flap 15 - 172kts.
Like I've said before our SOP was Flap 5, then the gear then the other stages of flap.
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Thx Chesty
So perhaps the NTSC statement was inaccurate/incomplete and 5 degrees WAS deployed before the gear
So following this we could say, a POSSIBLE scenario from a non Q driver:
5 degrees flap deployed, speed 134 knots calibrated
Gear down, loss of speed.
Almost immediately flaps lowered to 15 degrees.
Events move very quickly now....(!)
This reduces speed even further leading to sloppy controls but unnoticed since flying straight line on autopilot
Is it possibly that one pilot lowers flaps to 15 degrees whilst the other pilot engages the G/S on the autopilot?
In this case 2 coincidental simultaneous actions by 2 pilots lead to cockpit confusion. The pitch up is caused by the ILS/Autopilot but the pilots assume icing problems, either wing or tail stall
no criticism implied, only trying to learn...
So perhaps the NTSC statement was inaccurate/incomplete and 5 degrees WAS deployed before the gear
So following this we could say, a POSSIBLE scenario from a non Q driver:
5 degrees flap deployed, speed 134 knots calibrated
Gear down, loss of speed.
Almost immediately flaps lowered to 15 degrees.
Events move very quickly now....(!)
This reduces speed even further leading to sloppy controls but unnoticed since flying straight line on autopilot
Is it possibly that one pilot lowers flaps to 15 degrees whilst the other pilot engages the G/S on the autopilot?
In this case 2 coincidental simultaneous actions by 2 pilots lead to cockpit confusion. The pitch up is caused by the ILS/Autopilot but the pilots assume icing problems, either wing or tail stall
no criticism implied, only trying to learn...
Gender Faculty Specialist
Well just based on the info from the NTSB which stated that "Flap 10 was reached 20 seconds later" I would hazard a guess that they had been flying clean until they selected Flap 15.
Only based on my experience that it takes nowhere near 20 seconds for the flaps to travel from 5 to 10.
Only based on my experience that it takes nowhere near 20 seconds for the flaps to travel from 5 to 10.
Flaps 5 selected
Chesty said
Like I've said before our SOP was Flap 5, then the gear then the other stages of flap.
Like I've said before our SOP was Flap 5, then the gear then the other stages of flap.
The NTSB spoksman was asked a question about the flap setting before the gear was lowered and he said that it was Flaps 5. For some reason most posters here seem to be *assuming* that it was flaps 0 when there is no evidene for that anywhere that I am aware of. Other than the exception that I have listed the flap position prior to the start of the incident is simply not mentioned by official (or journalistic) sources.
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I apologize for sounding opinionated but I don't believe for one moment this crew with 6000 or so hours between them simply forgot to add power and stalled the airplane.
I listened to the NTSB statement again. It sure sounds like the "upset" occurred while flaps were in transition -somewhere between 5 and 10-. This sounds an awful lot like "result" was not such a poor choice of words after all.
I also listened to the ATC conversation (you can find the recording online). They were at 2300' for a while. If they did not power up when they leveled, seems to me they would have got stall warning long before -and, from what I understand of the DHC8-400 ice protection integration into stall awareness -which they selected- , the shaker was triggered 20 knots early. Could it be that their low airspeed was due to rapid ice buildup?
For the most part, it sounds like the crew did everything right. They were aware enough to switch on deicing equipment. They reported significant ice buildup to ATC. Do you really think the both of them forgot about the power levers during this time?
I listened to the NTSB statement again. It sure sounds like the "upset" occurred while flaps were in transition -somewhere between 5 and 10-. This sounds an awful lot like "result" was not such a poor choice of words after all.
I also listened to the ATC conversation (you can find the recording online). They were at 2300' for a while. If they did not power up when they leveled, seems to me they would have got stall warning long before -and, from what I understand of the DHC8-400 ice protection integration into stall awareness -which they selected- , the shaker was triggered 20 knots early. Could it be that their low airspeed was due to rapid ice buildup?
For the most part, it sounds like the crew did everything right. They were aware enough to switch on deicing equipment. They reported significant ice buildup to ATC. Do you really think the both of them forgot about the power levers during this time?
Gender Faculty Specialist
Jim
I only assumed they were clean before selection of Flap 15 because 20 seconds for the flaps to run from 5 to 10, as the NTSB have stated, is an awfully long time (unless I'm remembering incorrectly).
However, if you have some kind of flap power problem then the rate of movement is reduced significantly.
I only assumed they were clean before selection of Flap 15 because 20 seconds for the flaps to run from 5 to 10, as the NTSB have stated, is an awfully long time (unless I'm remembering incorrectly).
However, if you have some kind of flap power problem then the rate of movement is reduced significantly.
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Just to clarify, even though C Morgan's company has flaps 5 before gear down in their SOPs there is nothing wrong with selecting the gear down with flaps 0. Done it lots of times myself as this is left to pilots discretion at our company.
Nevertheless, in icing conditions with the ref speed increase switch on, most pilots use flaps 5 before selecting gear down. This gives a greater margin to the minimum speed and also a more comfortable nose attitude.
By the way, the speed increment added for icing conditions clean in the approach has for some time now been increased to 25 kts. Increments for flaps 5 etc. remain the same. Don't know if this has been adopted by other companies aswell.
Nevertheless, in icing conditions with the ref speed increase switch on, most pilots use flaps 5 before selecting gear down. This gives a greater margin to the minimum speed and also a more comfortable nose attitude.
By the way, the speed increment added for icing conditions clean in the approach has for some time now been increased to 25 kts. Increments for flaps 5 etc. remain the same. Don't know if this has been adopted by other companies aswell.
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To tell you the truth, my first thought on the day after the accident was that the crew didn't power-up after level off due to a distraction. As some people have admitted,this scenario does happen, even to very experienced crews. I didn't want to mention it at first because it is not a nice feeling to speculate pilot error without a lot of info to back it up.
Having done sim instructing as well as my own training on medium and heavy turboprops and jets I can count more than a dozen times when very experienced crew members (~10,000 hours) have let the speed decay when the A/P is on and no autothrottles. I've never had it happen in real-life, but in an intense sim session with distractions or abnormal situations it is quite possible. In every case I've seen, the crew has recognized the problem and corrected before a full-fledged stall but a couple of times they came very close.
This is a real possiblity in an aircraft on autopilot without autothrottles, but obviously this can even happen in aircraft with autothrottles because there are many situations where they are turned off. For example the B767 has no A/T when operating with an engine out and other aircraft also require the A/T to be disengaged, at least briefly, during the engine fail/fire drill (I'm not fully familiar with the A320/330/340 family but I don't think they require the A/T to be disengaged with an engine failure).
Here is my take on the accident:
It seems to me that icing was not as much an aerodynamical problem as it was a distraction for the crew. The pilot flying allowed the airspeed to decay and when the stick shaker activated one or both of the pilots recognized the low-speed situation and called for go-around power. With the significant nose-up trim that the aircraft would have been holding, the addition of power (with the autopilot now kicked off) would have initially pitched the nose up. I think the nose would have pitched up even without the pilot's input. As the pitch increased and the plane stalled the pusher would activate and lead to a rapid pitch decrease. The amount of ice present MAY (and I emphasize MAY) have decreased aircraft controllability during the upset. Once the upset began at this relatively low altitude the crew didn't have the time or altitude to properly recognize what was happening and recover.
To summarize, in most normal circumstances a crew flying without autothrottle will never forget to power-up in a level off, however, add one or more distraction to the mix (such as the PF "helping" with FMS programing, engine fail/fire drills, severe fatigue, or weather conditions such as icing or focusing on wx radar) and the possibility of speed decay is real. For those who say it could never happen to you, well I very much hope you are right as it is a preventable scenario. However, please be aware that it could happen to your fellow crew member so always be vigilant even as PNF.
Having done sim instructing as well as my own training on medium and heavy turboprops and jets I can count more than a dozen times when very experienced crew members (~10,000 hours) have let the speed decay when the A/P is on and no autothrottles. I've never had it happen in real-life, but in an intense sim session with distractions or abnormal situations it is quite possible. In every case I've seen, the crew has recognized the problem and corrected before a full-fledged stall but a couple of times they came very close.
This is a real possiblity in an aircraft on autopilot without autothrottles, but obviously this can even happen in aircraft with autothrottles because there are many situations where they are turned off. For example the B767 has no A/T when operating with an engine out and other aircraft also require the A/T to be disengaged, at least briefly, during the engine fail/fire drill (I'm not fully familiar with the A320/330/340 family but I don't think they require the A/T to be disengaged with an engine failure).
Here is my take on the accident:
It seems to me that icing was not as much an aerodynamical problem as it was a distraction for the crew. The pilot flying allowed the airspeed to decay and when the stick shaker activated one or both of the pilots recognized the low-speed situation and called for go-around power. With the significant nose-up trim that the aircraft would have been holding, the addition of power (with the autopilot now kicked off) would have initially pitched the nose up. I think the nose would have pitched up even without the pilot's input. As the pitch increased and the plane stalled the pusher would activate and lead to a rapid pitch decrease. The amount of ice present MAY (and I emphasize MAY) have decreased aircraft controllability during the upset. Once the upset began at this relatively low altitude the crew didn't have the time or altitude to properly recognize what was happening and recover.
To summarize, in most normal circumstances a crew flying without autothrottle will never forget to power-up in a level off, however, add one or more distraction to the mix (such as the PF "helping" with FMS programing, engine fail/fire drills, severe fatigue, or weather conditions such as icing or focusing on wx radar) and the possibility of speed decay is real. For those who say it could never happen to you, well I very much hope you are right as it is a preventable scenario. However, please be aware that it could happen to your fellow crew member so always be vigilant even as PNF.
Over the years, I have also seen several crews in the simulator forget to apply power on levelling off whilst distracted with other things. Usually this was noticed long before things got really interesting but on one occasion, nothing was done until the stick-shaker went and the auto-pilot fell out.
So, for those of you out there who steadfastly refuse to believe that an experienced crew could possibly manage to do this under any circumstance, you are quite simply mistaken.
So, for those of you out there who steadfastly refuse to believe that an experienced crew could possibly manage to do this under any circumstance, you are quite simply mistaken.