Dead Stick landings in jet transport aicraft
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Don't see why your left on manual reversion. Windmilling N2 should be enough to generate enough hydraulic pressure to keep you flying and if you start the APU you should have AC power and a perfectly fly able aircraft. Done it many times and even tried the autopilot
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Of course not all engine failures on takeoff occur at V1. But it's the most tricky moment for it to fail
I would debate the conclusion of this statement. A/C on the ground only yaws. I used to give crews a wet V1 and create a V2 with space above Vr. You could see them anticipate the V1 bang; it didn't happen, then rotate, then bang as the nose came off and they sniffed V2. All said it was more 'interesting/entertaining'.
I was had my own check, B738. We were a crew of 2 TRE's renewing a type rating with a TRE from another company. He thought he'd 'educate' us. An NDB with F40, into GA F15 with engine failure as gear was selected up. Ref 40 +5 = V2F15 so our engine failure check was just legal and it was greatly entertaining and educational. Must better, realistic (Bird strike at 400') and educational in a/c handling than the usual wet V1 bang, keep it straight on the ground then rotate. However, I wonder at the failure rate of such imagination and the subsequent fall-out from the Ops dept to the Training dept.
I would debate the conclusion of this statement. A/C on the ground only yaws. I used to give crews a wet V1 and create a V2 with space above Vr. You could see them anticipate the V1 bang; it didn't happen, then rotate, then bang as the nose came off and they sniffed V2. All said it was more 'interesting/entertaining'.
I was had my own check, B738. We were a crew of 2 TRE's renewing a type rating with a TRE from another company. He thought he'd 'educate' us. An NDB with F40, into GA F15 with engine failure as gear was selected up. Ref 40 +5 = V2F15 so our engine failure check was just legal and it was greatly entertaining and educational. Must better, realistic (Bird strike at 400') and educational in a/c handling than the usual wet V1 bang, keep it straight on the ground then rotate. However, I wonder at the failure rate of such imagination and the subsequent fall-out from the Ops dept to the Training dept.
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Don
Agreed. However, the amount of dirt you move may prove to be fatal. What if USAir had been in IMC when the birds hit? What if there was a low fog bank?
A37675
I'll admit to not remembering the details of the Air Canada incident, but the Air Transat crew, for example, got lucky simply because of a reroute that took them closer to the Azores.
Of course, those pilots did a amazing jobs, but let's not pretend that chance/fate/supernatural powers didn't play a part.
Not this black duck pal. They are still just aeroplanes. Forced landings are forced landings. I will just move a bit more dirt or water on contact.
A37675
That wasn't the opinion of the pilot who dead sticked the Air Canada Boeing 767 (The Gimli Glider event).
Of course, those pilots did a amazing jobs, but let's not pretend that chance/fate/supernatural powers didn't play a part.
Suggest you Google the USN P3 ditching at Adak. It's all been done before.
You just need to think about how you would handle it. And do some pilot stuff.
What you may call super natural powers, others call discipline and training. If it happens to you, you have the rest of your life to sort it out. Use the time wisely.
You just need to think about how you would handle it. And do some pilot stuff.
What you may call super natural powers, others call discipline and training. If it happens to you, you have the rest of your life to sort it out. Use the time wisely.
Understood but I would be very surprised if the aircraft was significantly different in any important way from the sim. If the model is realistic enough for general handling and engine failures on a ZFT conversion, then where are the problems?
You’re well within the tested flight envelope, as opposed to deep stalls, transsonic dives, spins, etc. It’s the same airframe just lacking in thrust. Makes the sums easier: just lift, drag and gravity now!
You’re well within the tested flight envelope, as opposed to deep stalls, transsonic dives, spins, etc. It’s the same airframe just lacking in thrust. Makes the sums easier: just lift, drag and gravity now!
there had never been a successful ditching of a big jet
https://aviation-safety.net/database...?id=19690113-0
https://aviation-safety.net/database...?id=19681122-0
Some unofficial guidance in this paper (p 9) - based on sim characteristics.
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@FullWings
A simple example where the sim might not have the required fidelity in the all-engines out case, and the existing usage of the sim would not test the case.
Suppose there is a surface which is hydraulically powered even in the event of single engine failure (it has 2 PCUs, perhaps, one powered ultimately by each engine). For all the "normal" failure cases for which the sim is qualified, all it needs to represent is the reduced speed (and maybe max deflection) of a surface with half the PCUs. During, as you say, startup the surface is totally unpowered - and the aircraft is stationary, so the surface can just "sit there" and no-one is going to care.
But suppose that when that same surface is unpowered, with NO operative PCUs, it then "floats" to the aerodynamic neutral position. that's not something it does in any of the "normal" cases above. So unless someone specifically modelled this behaviour, the sim won't do it - the surface will just sit at the normal/stowed position.
So when you try your all engines out approach in the sim, all the spoilers (for example) stay nicely deployed. the day you do it in the aircraft, half of them float up and significantly increase your drag, and maybe you don't actually make the runway.
The underlying issue is that the sim is not a first principle physics based model of the workings of the aircraft and all its components. Some of it IS physics based (like the equations of motion that actually "move" the flight model) but large chunks of it are empirical, or table/data based (like the actual aerodynamics, which are just data tables for KNOWN conditions, or the systems behaviour, which in some cases is just "effects based"). So the sim cannot reliably extrapolate to other conditions, as the basis of the modelling is simply not set up that way.
A simple example where the sim might not have the required fidelity in the all-engines out case, and the existing usage of the sim would not test the case.
Suppose there is a surface which is hydraulically powered even in the event of single engine failure (it has 2 PCUs, perhaps, one powered ultimately by each engine). For all the "normal" failure cases for which the sim is qualified, all it needs to represent is the reduced speed (and maybe max deflection) of a surface with half the PCUs. During, as you say, startup the surface is totally unpowered - and the aircraft is stationary, so the surface can just "sit there" and no-one is going to care.
But suppose that when that same surface is unpowered, with NO operative PCUs, it then "floats" to the aerodynamic neutral position. that's not something it does in any of the "normal" cases above. So unless someone specifically modelled this behaviour, the sim won't do it - the surface will just sit at the normal/stowed position.
So when you try your all engines out approach in the sim, all the spoilers (for example) stay nicely deployed. the day you do it in the aircraft, half of them float up and significantly increase your drag, and maybe you don't actually make the runway.
The underlying issue is that the sim is not a first principle physics based model of the workings of the aircraft and all its components. Some of it IS physics based (like the equations of motion that actually "move" the flight model) but large chunks of it are empirical, or table/data based (like the actual aerodynamics, which are just data tables for KNOWN conditions, or the systems behaviour, which in some cases is just "effects based"). So the sim cannot reliably extrapolate to other conditions, as the basis of the modelling is simply not set up that way.
I do understand that it’s not solving Navier-Stokes in real time around the aircraft for our benefit. However, does it have to extrapolate outside the model in order to produce a “realistic” total engine failure scenario?
The example you’re describing would mean that a multiple hydraulic failure would not be simulated accurately even with AEO. If it can’t do that, then we have a problem as there are QRH drills and performance data for this precise scenario.
If all the engines quit in real life, then it could be for multiple reasons: fuel starvation, ash ingestion, birdstrikes, icing, rollbacks, uncontained failures, etc. All these will generate different system and aerodynamic effects, so when practicing in the sim the absolute fidelity doesn’t really matter as you’ll have to deal with what you get on the day. On BA38 the engines were actually still producing thrust, not enough to quite make the runway, unfortunately.
I do get what you are saying and I think it applies very much in things that take you to the edge of the flight envelope and beyond. However, if you were ever unlucky enough to experience a total engine failure, what you get is what you get; we can train techniques that allow you to get the airframe down on a runway (or road or field or lake...) despite the rather unknown and variable nature of the aircraft’s actual performance. Generic solutions and exposure to what many regard as a doomsday scenario can only help.
The example you’re describing would mean that a multiple hydraulic failure would not be simulated accurately even with AEO. If it can’t do that, then we have a problem as there are QRH drills and performance data for this precise scenario.
If all the engines quit in real life, then it could be for multiple reasons: fuel starvation, ash ingestion, birdstrikes, icing, rollbacks, uncontained failures, etc. All these will generate different system and aerodynamic effects, so when practicing in the sim the absolute fidelity doesn’t really matter as you’ll have to deal with what you get on the day. On BA38 the engines were actually still producing thrust, not enough to quite make the runway, unfortunately.
I do get what you are saying and I think it applies very much in things that take you to the edge of the flight envelope and beyond. However, if you were ever unlucky enough to experience a total engine failure, what you get is what you get; we can train techniques that allow you to get the airframe down on a runway (or road or field or lake...) despite the rather unknown and variable nature of the aircraft’s actual performance. Generic solutions and exposure to what many regard as a doomsday scenario can only help.
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However, does it have to extrapolate outside the model in order to produce a “realistic” total engine failure scenario?
If I recall, in the sim, you'd use a lot of rudder to get out of an upset, and that's exactly what the FO did that day, which eventually led to the failure of the vertical stabilizer.
I think the A300 accident was more about over-enthusiastic and cyclic unnecessary use of rudder than any lack of sim fidelity. I dimly remember the report stating that the sim training program had been checked and found to be within the flight test and model data but the concern was that the course material promoted use of rudder over other controls at high AoA...
I’m not trying to argue that you can do really odd manoeuvres in the sim and have high confidence that they would be repeatable on the aircraft. However, I would expect that as the sim has to model for each engine the thrust/drag and system effects for quite a wide range of non-normal scenarios, it would be odd if there were significant differences to the real thing. On the 777 there is a QRH recall drill for dual engine failure/stall which involves turning both engines off and on and deploying the RAT: it would be somewhat of an omission if this wasn’t modelled correctly, seeing as it can take several minutes to idle from this condition at altitude.
I’m not trying to argue that you can do really odd manoeuvres in the sim and have high confidence that they would be repeatable on the aircraft. However, I would expect that as the sim has to model for each engine the thrust/drag and system effects for quite a wide range of non-normal scenarios, it would be odd if there were significant differences to the real thing. On the 777 there is a QRH recall drill for dual engine failure/stall which involves turning both engines off and on and deploying the RAT: it would be somewhat of an omission if this wasn’t modelled correctly, seeing as it can take several minutes to idle from this condition at altitude.
Did it in the box as part of L1011 conversion. TOC, flew into volcanic ash at night, one by one the engines failed. Turned back, set speed then checklists for single engine failures, then multiple engine failures, hydraulic systems, electical systems pressurisation failures. Calculation of no flap, no slat speeds, checklists for that. Manual gear extension, all the time trying to relight an engine. Of course that didn't happen. Both pilots and FE working like one armed paper hangers but we did it. I think I lost weight, the session lasted about 40 minutes and I have never felt such satisfaction or confidence as then.
ECON cruise, LR cruise...
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...also of interest is training the dual engine flameout after departure - as demonstrated by Sullenberger (and Ryanair @ CIA) - that's where the birdstrikes happen. We practice a profile with dual failure at 2.800ft - too low for a turnback - and it generally works well (although you can imagine what the wreckage would look like if it were to happen for real)
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My last company gave us a dual failure at 800' heading out to sea out of AYT. Dodge the buildings then ditch. you had about 30 seconds.....
Then reposition and a normal departure right after. They really should have done the ditching drill at the end of the session to be fair.....
Then reposition and a normal departure right after. They really should have done the ditching drill at the end of the session to be fair.....
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It's good practice of basic airmanship. Guys frequently add drag too early.
Airliners can achieve at least 2.5 nm (Airbus guidance) to 3 nm (demonstrated ) per 1000' of altitude. 30,000'? 75-90 nm gliding range if you fly the plane correctly.
Windmilling engines provide a significant amount of hydraulic pressure (ex. US 1549), especially if you don't move the controls.
Every descent/arrival uses the basics of energy mgt. Gliding is no different.
IMO pilots real nightmare scenario is a cabin fire.
Airliners can achieve at least 2.5 nm (Airbus guidance) to 3 nm (demonstrated ) per 1000' of altitude. 30,000'? 75-90 nm gliding range if you fly the plane correctly.
Windmilling engines provide a significant amount of hydraulic pressure (ex. US 1549), especially if you don't move the controls.
Every descent/arrival uses the basics of energy mgt. Gliding is no different.
IMO pilots real nightmare scenario is a cabin fire.
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IMHO success depends mainly on whether you can see where you go. Drop out of a low overcast during night and you're back to "switch on landing lights, if you don't like what you see, switch'em off again" while you might have better options if you can see an airport in range or at least look for a flattish, longish place to set it down.
We trained this on the SIM and I think it is a good idea to do so, but I wouldn't bet on the experience to be fully realistic, especially regarding availability of engine driven hydraulics.
Having (hydraulics) power available to move slats/flaps and especially a speed brake thus allowing better control of glideslope would be helpful, too, as most of us are probably not too good at judging how far we'll get without thrust lower down (e.g. when to turn to base/final) and having flaps available would improve survivability d/t lower speeds.
And why is it called "dead-stick" if it's the engines that are dead?
We trained this on the SIM and I think it is a good idea to do so, but I wouldn't bet on the experience to be fully realistic, especially regarding availability of engine driven hydraulics.
Having (hydraulics) power available to move slats/flaps and especially a speed brake thus allowing better control of glideslope would be helpful, too, as most of us are probably not too good at judging how far we'll get without thrust lower down (e.g. when to turn to base/final) and having flaps available would improve survivability d/t lower speeds.
And why is it called "dead-stick" if it's the engines that are dead?
This is a good one. Lots to discuss. Read all of it as it appears to qualify as dead stick:
https://en.wikipedia.org/wiki/TACA_Flight_110
And this from the Feds:
http://lessonslearned.faa.gov/ll_mai...=40&LLTypeID=2
https://en.wikipedia.org/wiki/TACA_Flight_110
And this from the Feds:
http://lessonslearned.faa.gov/ll_mai...=40&LLTypeID=2
Last edited by bafanguy; 27th Aug 2016 at 21:40.
