TOM stall?
Joined: Sep 2003
Posts: 361
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From: uk
I just hope that the crew involved get a bit of a slap on wrists,
bit more training and then get back in the aircraft.
The slap is for letting the aircraft getting into the state in the first place, the training because we all can do with more of it, I know I can sometimes.
The best end result for all.
We can only wait and see.
259.
bit more training and then get back in the aircraft.
The slap is for letting the aircraft getting into the state in the first place, the training because we all can do with more of it, I know I can sometimes.
The best end result for all.
We can only wait and see.
259.
Joined: Jun 2000
Posts: 4,507
Likes: 4
From: last time I looked I was still here.
It would seem that. if the speed of 90kts was true, they must have been very close to a full stall, certainly past stick shaker I would have thought. If this speed was caused by a sevree pull up then I expect there was quite some g-loading. The more learned bretheren amongst us could elaborate. I'm curious as to whether the elevator would have enough influence to affect a nose over recovery. If so, there must have been 'lots of stuff' floating around the cabin ceiling. If not, would some roll habe been required to recover this beast. I would have expected the elevator to have been as useful as wet fish at this speed.
Were there any eye -witnesses, or were they IMC? I've not read all earlier posts to note the Wx or time of day. If not, the subsequent aeros must have been entertaining to the locals who have their fair share of summer inverted antics along the beach front.
Were there any eye -witnesses, or were they IMC? I've not read all earlier posts to note the Wx or time of day. If not, the subsequent aeros must have been entertaining to the locals who have their fair share of summer inverted antics along the beach front.
Joined: Nov 2003
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From: Over the Moon
Nose high speed decreasing unusual attitude/upset.
You can use roll to aid lowering the nose if you have a very high nose attitude but only if you have sufficient speed in hand in the first place. Interestingly Boeing advocate up to full nose down elevator and a REDUCTION in thrust to aid recovery. The order is elevator, trim, thrust, roll and the roll has a caution attached as does the use of trim. By using the elevator aggresively your decreasing your angle of attack and making a stall due to roll much less likely (you can't stall at 0G) and reducing power will aid the pitch down initialy.
If your 40 nose up in the stick shaker then I'd reckon you don't have that speed in hand and by rolling your going to increase your angle of attack on one wing so could easily induce the stall you wish to avoid and make your subsequent recovery harder as the stall on one wing could induce even more roll. If you want to see that in action then look at the video of the Nimrod crash during an airshow in Toronto, I imagine its on U tube. Not exactly the same as they were in an established turn with G on but it gets the point of Mvr stall accross in a very tragic and poignent way.
With 40 nose up and stick shake you'd be doing the approach to stall checklist I would imagine. That and praying to whichever God you happen to believe in.
Out of interest in the air force with nose v high, speed low and rapidly reducing we were always taught to go to idle and centralise everything, wait for the aircraft to fall out and once speed was on the way back up effect a recovery using nose low techniques. Not as a technique in the QRH or the FCTM though.
You can use roll to aid lowering the nose if you have a very high nose attitude but only if you have sufficient speed in hand in the first place. Interestingly Boeing advocate up to full nose down elevator and a REDUCTION in thrust to aid recovery. The order is elevator, trim, thrust, roll and the roll has a caution attached as does the use of trim. By using the elevator aggresively your decreasing your angle of attack and making a stall due to roll much less likely (you can't stall at 0G) and reducing power will aid the pitch down initialy.
If your 40 nose up in the stick shaker then I'd reckon you don't have that speed in hand and by rolling your going to increase your angle of attack on one wing so could easily induce the stall you wish to avoid and make your subsequent recovery harder as the stall on one wing could induce even more roll. If you want to see that in action then look at the video of the Nimrod crash during an airshow in Toronto, I imagine its on U tube. Not exactly the same as they were in an established turn with G on but it gets the point of Mvr stall accross in a very tragic and poignent way.
With 40 nose up and stick shake you'd be doing the approach to stall checklist I would imagine. That and praying to whichever God you happen to believe in.
Out of interest in the air force with nose v high, speed low and rapidly reducing we were always taught to go to idle and centralise everything, wait for the aircraft to fall out and once speed was on the way back up effect a recovery using nose low techniques. Not as a technique in the QRH or the FCTM though.
Joined: Jun 2000
Posts: 4,507
Likes: 4
From: last time I looked I was still here.
Ashling:
I agree with your assessment that a roll might cause the a wing to come closer to stall. The idea of reducing power on a low wing a/c was with me, but it would not be intuative to the average airline crew, especially not close to the ground. Your military recovery technique will work (I've done it when flicking off the top of a roll and screwing up), but you need lots of height. As the elevator might be 'like a wet fish in a gale' increasing stab trim might work, but you'd have to be very quick to remove that trim during the nose over recovery. Combinations of many things might be needed, but I'd enjoy seeing the FDR put onto an instrument display and learning what happened, why and then learn again from the crew's subsequent actions.
There have been some interesting reconstructions done e.g. about the China Airlines B747 that went into a nose down corkscrew due to engine out and a stall at CRZ level. I didn't yet see one about the Airbus in Paris that went high nose up at the OM. I saw only a still photo. There was the one in the far East that went from Approach mode into G/A and they stalled and did not recover. There must be lots to learn and I hope we have the chance.
I agree with your assessment that a roll might cause the a wing to come closer to stall. The idea of reducing power on a low wing a/c was with me, but it would not be intuative to the average airline crew, especially not close to the ground. Your military recovery technique will work (I've done it when flicking off the top of a roll and screwing up), but you need lots of height. As the elevator might be 'like a wet fish in a gale' increasing stab trim might work, but you'd have to be very quick to remove that trim during the nose over recovery. Combinations of many things might be needed, but I'd enjoy seeing the FDR put onto an instrument display and learning what happened, why and then learn again from the crew's subsequent actions.
There have been some interesting reconstructions done e.g. about the China Airlines B747 that went into a nose down corkscrew due to engine out and a stall at CRZ level. I didn't yet see one about the Airbus in Paris that went high nose up at the OM. I saw only a still photo. There was the one in the far East that went from Approach mode into G/A and they stalled and did not recover. There must be lots to learn and I hope we have the chance.
Joined: Nov 1998
Posts: 304
Likes: 7
From: netherlands
"Out of interest in the air force with nose v high, speed low and rapidly reducing we were always taught to go to idle and centralise everything, wait for the aircraft to fall out and once speed was on the way back up effect a recovery using nose low techniques. Not as a technique in the QRH or the FCTM though"
That depends on the particular aircraft. I know of some that would NOT recover using that technique. Also you need lots of altitude if you just let it fall. Not a good technique after or during a go-around.
That depends on the particular aircraft. I know of some that would NOT recover using that technique. Also you need lots of altitude if you just let it fall. Not a good technique after or during a go-around.
Joined: Nov 2003
Posts: 779
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From: Over the Moon
Sleeper
Your quite right I haven't flown everything in the airforces inventory just a mix of whizz jet and multi.
The nose high speed rapidly blah blah thing was purely out of interest rather than an attempt at a recommended technique for a Boeing. Both you and RAT 5 are quite correct it will take quite some height to recover and quite probably more than this crew had available although it is equally possable it would work depending on trajectory, attitude etc.
In the real case all you can do is follow Boeings recommended stall recovery.
Agree with you RAT 5 it would be very interesting to see the FDR.
Your quite right I haven't flown everything in the airforces inventory just a mix of whizz jet and multi.
The nose high speed rapidly blah blah thing was purely out of interest rather than an attempt at a recommended technique for a Boeing. Both you and RAT 5 are quite correct it will take quite some height to recover and quite probably more than this crew had available although it is equally possable it would work depending on trajectory, attitude etc.
In the real case all you can do is follow Boeings recommended stall recovery.
Agree with you RAT 5 it would be very interesting to see the FDR.
Joined: Dec 2001
Posts: 189
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From: London
Regarding the fidelity of sims to real life, recall the B767 sim in regard to the Lauda Air 767 crash in Thailand. Initially the pilots were criticised for not acting more quickly after the deployment of the thrust reverser, as the re-enactment in the Boeing sim indicated they had plenty of time to act and recover the situation. NTSB suspected all was not right, and did a lot of number-crunching and, to cut a long story short, it turned out in the end that the pilots actually only had five seconds after being thrown this totally unexpected and untrained for situation.
Think that after that B got an certification exemption on having to prove that accidental in-flight thrust-reverser deployment on the 777 was recoverable.
Think that after that B got an certification exemption on having to prove that accidental in-flight thrust-reverser deployment on the 777 was recoverable.
The Cooler King
Joined: Feb 2004
Posts: 1,717
Likes: 30
From: Europe
If the above descriptions are accurate, then everyone was very lucky to get back on the deck safely.
No time to be terrified initially but I am sure that the crew concerned have been through the mill so far.
As I have said in the Virgin thread a while ago, the amount of rubbish talk from some posters is embarassing and I'm sure the crew of the above flight really appreciate your comments.
There has been heated debate about a separate forum where professionals can discuss stuff like this without having to deal with the drivvle that some of you have come out with over the past few pages.
Will I have access to this separate forum?
At this stage in my career, definitely not.
From an industry PR point of view, some of the comments made on incidents here in the past put all of us in a really bad light.
In fact, I think that if the powers that be made a separate area and just emailed the professionals the link, none of the others would even notice it was there, and all would trundle on as usual.
No time to be terrified initially but I am sure that the crew concerned have been through the mill so far.
As I have said in the Virgin thread a while ago, the amount of rubbish talk from some posters is embarassing and I'm sure the crew of the above flight really appreciate your comments.
There has been heated debate about a separate forum where professionals can discuss stuff like this without having to deal with the drivvle that some of you have come out with over the past few pages.
Will I have access to this separate forum?
At this stage in my career, definitely not.
From an industry PR point of view, some of the comments made on incidents here in the past put all of us in a really bad light.
In fact, I think that if the powers that be made a separate area and just emailed the professionals the link, none of the others would even notice it was there, and all would trundle on as usual.
Last edited by Farrell; 23rd November 2007 at 16:45.
Joined: Apr 2006
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From: an expensive mansion
Joined: Oct 1999
Posts: 23
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From: Bishops Stortford, UK
Heard of a similar incident in a previous life: mis-handled G/Around on a 737-200 where the crew recovered from a nose-high attitude by keeping G/A thrust and almost full down elevator. Resulting in a "parabolic" recovery with the minimum speed somewhere approx 10kts below stick-shaker for the config.
At zero "G" the a/c WILL fly without stalling as long as it can be maintained. But there has to come a point where elevator effectiveness and the aircraft energy will be insufficient to continue the recovery manoeuvre. Then only lots of altitude will help..................
Interesting that it still can happen.............
At zero "G" the a/c WILL fly without stalling as long as it can be maintained. But there has to come a point where elevator effectiveness and the aircraft energy will be insufficient to continue the recovery manoeuvre. Then only lots of altitude will help..................
Interesting that it still can happen.............
Joined: Mar 2006
Posts: 120
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From: England
Until the full facts are reported by the AAIB, it is only speculation that the aircraft was 40 degrees nose up and at 90 kts airspeed simultaneously during a go around.
The quote from flight states:
"sources say that incident on 23 September involved a go-around following an uncommanded power reduction that left the aircraft at stalling speed during the approach".
It doesn't say "during the go around"
Flight continues:
"The crew disconnected the autopilot and autothrottle to recover the aircraft successfully to safe flight, but witnesses report that the nose-up attitude during recovery exceeded 40° and the airspeed reduced to approximately 90kt (166km/h) at its lowest point."
This 90 kts may well have been during the initial approach, not during the go around.
"The crew then carried out a safe landing at the airport, the AAIB confirms."
FB
The quote from flight states:
"sources say that incident on 23 September involved a go-around following an uncommanded power reduction that left the aircraft at stalling speed during the approach".
It doesn't say "during the go around"
Flight continues:
"The crew disconnected the autopilot and autothrottle to recover the aircraft successfully to safe flight, but witnesses report that the nose-up attitude during recovery exceeded 40° and the airspeed reduced to approximately 90kt (166km/h) at its lowest point."
This 90 kts may well have been during the initial approach, not during the go around.
"The crew then carried out a safe landing at the airport, the AAIB confirms."
FB
Joined: Feb 1999
Posts: 813
Likes: 16
From: MAN
Yep, but someone else's hole.
Alpha Floor etc, has not prevented serious jet upset. The Pilots need to be designed into the flight envelope not OUT of it. Monitor the shop boys, it will take your head off if neglected!
Alpha Floor etc, has not prevented serious jet upset. The Pilots need to be designed into the flight envelope not OUT of it. Monitor the shop boys, it will take your head off if neglected!
Joined: Mar 2006
Posts: 1,771
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From: West Sussex
Non - pilots
Rainboe & co,
I appreciate your point re. non pilots posting; I don't make much attempt to hide my identity, trust anyone sadly interested knows me.
In fact I ( and a lot of others ) learn a lot from reading such threads - including this one - and I have done a lot of unofficial 'hands-on' with light aircraft - including the true Hollywood scenario of my trusty hungover / maybe drugged pilot passing out on me, it really does happen !
Leaving me to circle until he came round...
He did, so I didn't have to knobble any future career of his with an emergency - always wondered if I should have, but the interviwers seemed to have him sized up anyway. NOT anything to do with Dunsfold BTW.
So while a little learning is a dangerous thing, it seems better than nothing !
BTW I knew a Flight Engineer on Concorde; he reckoned he & his colleagues tried to recreate the Sioux City recovery in a Sim, and anyone who got within 40 miles was doing very well ! Respect indeed ! You may be able to corroborate that.
On reflection I am qualified to 'pilot' anything up to 200 tons, but that's at sea level ( or less if I really screw up ) with an IAS unlikely to exceed 30 knots !
Yours, slightly trained in aeronautics, trials / aerial photographer...
I appreciate your point re. non pilots posting; I don't make much attempt to hide my identity, trust anyone sadly interested knows me.
In fact I ( and a lot of others ) learn a lot from reading such threads - including this one - and I have done a lot of unofficial 'hands-on' with light aircraft - including the true Hollywood scenario of my trusty hungover / maybe drugged pilot passing out on me, it really does happen !
Leaving me to circle until he came round...
He did, so I didn't have to knobble any future career of his with an emergency - always wondered if I should have, but the interviwers seemed to have him sized up anyway. NOT anything to do with Dunsfold BTW.
So while a little learning is a dangerous thing, it seems better than nothing !
BTW I knew a Flight Engineer on Concorde; he reckoned he & his colleagues tried to recreate the Sioux City recovery in a Sim, and anyone who got within 40 miles was doing very well ! Respect indeed ! You may be able to corroborate that.
On reflection I am qualified to 'pilot' anything up to 200 tons, but that's at sea level ( or less if I really screw up ) with an IAS unlikely to exceed 30 knots !
Yours, slightly trained in aeronautics, trials / aerial photographer...