Continental TurboProp crash inbound for Buffalo
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But it does sound more and more like... 'Aviate, Navigate, Communicate' might have been lost in the moments leading up to the departure.
Am I right in thinking that there are really big differences between the shaker and pusher activation, and the behaviour in a genuine tail-stall? Such as other visual and aural confirmations of stall-recovery activation... it would be tragic indeed if ice/tail-stall 'thinking' had come to dominate, and a fairly straightforward recovery fought against.
The fact that 'speed & power increase' is warned against in some tail-stall recovery instruction also gives pause for thought...
The LHR/Staines Trident accident, whilst different in so many ways, was a case of 'disbelief, question, then fight the pusher' and included elements of poor airspeed monitoring coming close on the tail of configuration change (inadvertent).
Am I right in thinking that there are really big differences between the shaker and pusher activation, and the behaviour in a genuine tail-stall? Such as other visual and aural confirmations of stall-recovery activation... it would be tragic indeed if ice/tail-stall 'thinking' had come to dominate, and a fairly straightforward recovery fought against.
The fact that 'speed & power increase' is warned against in some tail-stall recovery instruction also gives pause for thought...
The LHR/Staines Trident accident, whilst different in so many ways, was a case of 'disbelief, question, then fight the pusher' and included elements of poor airspeed monitoring coming close on the tail of configuration change (inadvertent).
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For reference, I did a quick check on the 15 Saab 340 incidents reported at Aviation Safety Network, which may have been familiar to the captain of Colgan 3407.
Notably, in all four incidents where icing was a factor (in 1993, 1998, 2002 and 2006), the airplane stalled before the stall warning activated.
Quote from the 2002 event:
So based on those incidents, we may suspect the captain of 3407 might well have been inclined to interpret the stick shake and push as signs of a tailplane stall instead of an impending wing stall. In the tailplane stall scenario pulling the yoke would be the correct response.... but this time it wasn't.
Makes you think how easily things can go wrong
Notably, in all four incidents where icing was a factor (in 1993, 1998, 2002 and 2006), the airplane stalled before the stall warning activated.
Quote from the 2002 event:
The investigation found that despite being certified to all required certification standards at the time, the Saab 340 aircraft can suffer from an aerodynamic stall whilst operating in icing conditions without the required warnings being provided to flight crew. This problem had been highlighted when the aircraft was introduced to operations in Canada and as a result a modified stall warning system was mandated for aircraft operated in Canada. This modification was not fitted to other Saab 340 aircraft worldwide.
Makes you think how easily things can go wrong
Last edited by snowfalcon2; 18th Feb 2009 at 12:34.
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The last five fatal airline accidents in the US have been commuter airplanes. The last three had on board "graduates" of the same flight school in Florida. Are we seeing a trend?
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autopilots
some autopilots do too much and unless fully integrated with autothrottles are more dangerous than NO autopilot.
The best autopilot I have ever had was the least complex. IF I WANTED TO CAPTURE AN ALTITUDE , I had to select ZERO on the rate of climb or descent...I had to capture the altitude and I never forgot to adjust the throttles. Why? Because I was controlling the whole thing and not depending on automation to capture a preselected altitude. My eyes were focused on the instrument panel, or we would miss our altitude.
On later planes, with auto altitude capture, we were supposed to use the autothrottles at all time, to avoid the postulated scenario.
We still really don't know what happened yet, but a combination of a tailplane stall (which bombardier says can't happen in this type), airspeed mismanagement, incorrect response to an ambiguous set of circumstances all add up to problems.
I can also imagine an eager copilot trying to help program an FMS that was unfamiliar to the captain and if so, both pilots going head down and not watching the instruments...it happened to an eastern L1011 with a little landing gear light problem and they had a flight engineer.
COCKPIT DISCIPLINE IS VITAL.
The best autopilot I have ever had was the least complex. IF I WANTED TO CAPTURE AN ALTITUDE , I had to select ZERO on the rate of climb or descent...I had to capture the altitude and I never forgot to adjust the throttles. Why? Because I was controlling the whole thing and not depending on automation to capture a preselected altitude. My eyes were focused on the instrument panel, or we would miss our altitude.
On later planes, with auto altitude capture, we were supposed to use the autothrottles at all time, to avoid the postulated scenario.
We still really don't know what happened yet, but a combination of a tailplane stall (which bombardier says can't happen in this type), airspeed mismanagement, incorrect response to an ambiguous set of circumstances all add up to problems.
I can also imagine an eager copilot trying to help program an FMS that was unfamiliar to the captain and if so, both pilots going head down and not watching the instruments...it happened to an eastern L1011 with a little landing gear light problem and they had a flight engineer.
COCKPIT DISCIPLINE IS VITAL.
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Still it is a strange accident.
It seems, that the aircraft tail stalled, when flap 15 was selected. The aircraft pitched up, and then the wings stalled, and the stick shaker activated.
Why did the aircraft pitch up, and not down?? Could this accident be caused by a combination of icing and the CG far beyond its af limit?
Cheers
SE210
It seems, that the aircraft tail stalled, when flap 15 was selected. The aircraft pitched up, and then the wings stalled, and the stick shaker activated.
Why did the aircraft pitch up, and not down?? Could this accident be caused by a combination of icing and the CG far beyond its af limit?
Cheers
SE210
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some autopilots do too much and unless fully integrated with autothrottles are more dangerous than NO autopilot.
The best autopilot I have ever had was the least complex. IF I WANTED TO CAPTURE AN ALTITUDE , I had to select ZERO on the rate of climb or descent...I had to capture the altitude and I never forgot to adjust the throttles. Why? Because I was controlling the whole thing and not depending on automation to capture a preselected altitude. My eyes were focused on the instrument panel, or we would miss our altitude.
On later planes, with auto altitude capture, we were supposed to use the autothrottles at all time, to avoid the postulated scenario.
The best autopilot I have ever had was the least complex. IF I WANTED TO CAPTURE AN ALTITUDE , I had to select ZERO on the rate of climb or descent...I had to capture the altitude and I never forgot to adjust the throttles. Why? Because I was controlling the whole thing and not depending on automation to capture a preselected altitude. My eyes were focused on the instrument panel, or we would miss our altitude.
On later planes, with auto altitude capture, we were supposed to use the autothrottles at all time, to avoid the postulated scenario.
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"Pilot action may have led to......"
After reading the new information given in the link attached to post #615, it appears to me that although present in the approach area, icing did NOT cause this tragic accident.
Why did the aircraft pitch up, and not down??
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That Flight Deck
Is one place I would never want to be in its last moments. Do we know who was FP? RHS had far more experience in type, was the decision based on her hours, was she flying? The CRM would have been challenged in so many ways, not the least of which was weather and workload. The discrepancy in age and experience, the last leg of a long long day. Whoever was flying/monitoring, it starts to look like the pilots got behind the a/c. Not an a/c to play catch-up with. RIP.
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The system in use is by specification is likely (although it could be otherwise) a Thales (open architecture avionic) system.
By open architecture my question is with all the processes of flight can the avionic system be customized for the profile of the aircraft it is suited to?
If slow speed is detected then the LCD which can display the IAS would change to a brighter color, flash, beep, or otherwise be more noticeable when in perhaps a de-ice mode... (maybe it does?)
I also question the logic that the system(s) sometimes display as making one assume it has and is looking ahead, in terms of flight management or that it creates a "virtual" environment for a real time situation.
By open architecture my question is with all the processes of flight can the avionic system be customized for the profile of the aircraft it is suited to?
If slow speed is detected then the LCD which can display the IAS would change to a brighter color, flash, beep, or otherwise be more noticeable when in perhaps a de-ice mode... (maybe it does?)
I also question the logic that the system(s) sometimes display as making one assume it has and is looking ahead, in terms of flight management or that it creates a "virtual" environment for a real time situation.
some autopilots do too much and unless fully integrated with autothrottles are more dangerous than NO autopilot.
The best autopilot I have ever had was the least complex. IF I WANTED TO CAPTURE AN ALTITUDE , I had to select ZERO on the rate of climb or descent...I had to capture the altitude and I never forgot to adjust the throttles. Why? Because I was controlling the whole thing and not depending on automation to capture a preselected altitude. My eyes were focused on the instrument panel, or we would miss our altitude.
On later planes, with auto altitude capture, we were supposed to use the autothrottles at all time, to avoid the postulated scenario.
The best autopilot I have ever had was the least complex. IF I WANTED TO CAPTURE AN ALTITUDE , I had to select ZERO on the rate of climb or descent...I had to capture the altitude and I never forgot to adjust the throttles. Why? Because I was controlling the whole thing and not depending on automation to capture a preselected altitude. My eyes were focused on the instrument panel, or we would miss our altitude.
On later planes, with auto altitude capture, we were supposed to use the autothrottles at all time, to avoid the postulated scenario.
Being a bit ignorant of turbo props am surprised to hear they have autopilot yet no autothrottle.
I recall a potential incident on the B737-300 (some 25 years ago!) where I had disengaged the autothrottle as we had to ensure a minimum N1 in those days with engine anti ice on. As we levelled at the approach altitude I noticed the speed decreasing below the minimum for the config and was able to rapidly apply manual thrust to correct same. We were nowhere near the stall but it was a salutary lesson.
As you say, pth, NO autopilot is probably better! At least in that situation the PF is generally very aware of what his/her primary task is.
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As you say, pth, NO autopilot is probably better! At least in that situation the PF is generally very aware of what his/her primary task is.
Yeah, hand flying is tiring, but I always knew EXACTLY what was going on with the aircraft. And we did have very long days, I flew over 12 hours in a day many times. (flew 12 hours...duty day 15 hours, and say 8-11 legs?) Without an autopilot.
I would have thought that the Q400 would have had autothrottles....guess I would have known that if I hadn't turned down a job on one. But I can totally see getting distracted after a long day, chatting about crap, and no one is watching the instruments. Especially over worked, underpaid US regional pilots.
Whole thing sucks.
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Autopilot
Too many times the A/P intrudes on CRM. It has been my sense for some time that a cockpit environment that blurs auto with manual creates more work (hazard) than it allays. Carrying the third "pilot" into a critical phase of flight seems dangerous to me, (also to Bombardier?). Without conclusion, I would say, see BA038? It also strikes me, as others, that an a/p w/o autothrottle might be asking too much of the electric/manual interface. What pilot would be excused from "descent to assigned altitude" without added power when level? No human, certainly. What Pilot would be excused from maintaining GS to the Stall without adding thrust?
Last edited by airfoilmod; 18th Feb 2009 at 14:31.
A Half-Automated a/c
Thank you Otto for your story. Frightening ourselves makes for a lifelong lesson if we recover -- and a lesson for those reading the eventual report if we don't.
Autopilot level off from a climb without throttle adjustment just exposes us to extra airspeed.
Autopilot level off from a descent without autothrottles we have now seen is a bit of a trap. However I have to say that I don't know of any similar accidents.
Does the Q400 simply level off and start bleeding airspeed without any indications? Is setting this trap something that should be happening during high workload?
Should the autopilot instead be set to descent rate and the altitude alerter set to clue the f/c to do the level off? At least there will be an expected chime or suchlike.
A 31 degree pitchup on stall is an excellent reason for the stick pusher, but it looks like the stick shaker and pusher need to get on the job considerably sooner when there's ice.
Autopilot level off from a climb without throttle adjustment just exposes us to extra airspeed.
Autopilot level off from a descent without autothrottles we have now seen is a bit of a trap. However I have to say that I don't know of any similar accidents.
Does the Q400 simply level off and start bleeding airspeed without any indications? Is setting this trap something that should be happening during high workload?
Should the autopilot instead be set to descent rate and the altitude alerter set to clue the f/c to do the level off? At least there will be an expected chime or suchlike.
A 31 degree pitchup on stall is an excellent reason for the stick pusher, but it looks like the stick shaker and pusher need to get on the job considerably sooner when there's ice.
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bartbandy and dfirefly bob
funny, I've flown both the 737 and the MU2...and we both seem to have the seem feeling regarding autopilot useage.
With the MU2, I figured I better get good at flying it and practice hand flying all I could. And yes, you are freaking tired after a multiple leg day.
FFB, I remember tha bit about min N1...from that leveee landing bit about 21 years ago. CFMs1!!!!
We are teaching our pilots to fly the wrong way...just to make sure they stay awake with min rest and crappy companies!
With the MU2, I figured I better get good at flying it and practice hand flying all I could. And yes, you are freaking tired after a multiple leg day.
FFB, I remember tha bit about min N1...from that leveee landing bit about 21 years ago. CFMs1!!!!
We are teaching our pilots to fly the wrong way...just to make sure they stay awake with min rest and crappy companies!
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With the MU2, I figured I better get good at flying it and practice hand flying all I could. And yes, you are freaking tired after a multiple leg day.
We are teaching our pilots to fly the wrong way...just to make sure they stay awake with min rest and crappy companies!