I don’t think anyone can say at this point that there was no effort get out of it. All we see is a video of it in a flat spin. What percentage of heavy turboprops are certified to recover from a flat spin? Probably none.
The spin dynamics of a multiengine transport airplane are very different from those of a glider.Thanks.
What you're telling me is that I should not fly in such planes since as we saw, they will spin and they can't be recovered.
I would think though that if they pull the power, they're flying a glider and if CG is within limits, the nose down stick should respond.
AI agrees:The spin dynamics of a multiengine transport airplane are very different from those of a glider.
The question begs. It seems to me that if a big aircraft, be it an ATR 72, a 737 Max or an Airbus can't get out of a spin yet it can enter a deadly one, as we've seen in the recent past, they would all have serious design faults regarding the CG envelope.AI agrees:
Which tells me I should not fly in these planes if safety is a concern?
Which tells you you shouldn’t fly behind pilots who get multiengine transport airplanes into spins.AI agrees:
Which tells me I should not fly in these planes if safety is a concern?
Agreed. Let me know how you obtain this kind of information before you get on a plane...Which tells you you shouldn’t fly behind pilots who get multiengine transport airplanes into spins.
No need , you are safer there by something like a factor of 10 than on any glider …Agreed. Let me know how you obtain this kind of information before you get on a plane...
I've no experience flying anything that big, but I suspect any transport-category aircraft can get into a non-recoverable situation of some sort or other.Which tells me I should not fly in these planes if safety is a concern?
Of course it isn't. It was a flat spin. Not recoverable unless you can shift the CG.I believe a plane like ATR 72 may actually not be recoverable in certain spin scenarios ( depending on COG configuration ) ….
So we need JB's opinion, really? The rudder authority in a flat spin is zero in any aircraft, not just an ATR.Juan Browne (Blancolirio, linked above) says a (flat?) spin in this airframe may be un-recoverable. He cites the weight of the engines and insufficient rudder authority.
AF 447 was not a flat spin, not even a deep stall. They held the 330 in a stall until it was too late to recover.Air France accident over the ocean in Brazil also hit the water with a flat spin.
I seem to recall them considering doing hot leading edges on the Dash 8 Q400, it has enough excess power to provide acceptable performance even when supplying the anti-ice system. Even you don't get the leading edges hot enough it's even worse than boots.Any anti-ice solutions for turboprops like ATR such as hot leading edges? De-ice boots allowing ice formation is only option?
It's not zero in any aircraft and in the case of the ATR it should be more effective in an upright flat spin than many other aircraft, as practically none of the rudder is blanked by the elevator.So we need JB's opinion, really? The rudder authority in a flat spin is zero in any aircraft, not just an ATR.
Okay, then read it is "negligible." Why do you believe elevator blanketing is the important factor? The Piper Tomahawk should be great at flat spins then.It's not zero in any aircraft and in the case of the ATR it should be more effective in an upright flat spin than many other aircraft, as practically none of the rudder is blanked by the elevator.
The one crew I can think of that’s spun a transport category airplane is dead, so if you pick a crew that’s not dead, you should be safe from spins in transport category aircraft.Agreed. Let me know how you obtain this kind of information before you get on a plane...
I didn't say it's "the important" factor. You made a blanket statement regarding rudder authority.Okay, then read it is "negligible." Why do you believe elevator blanketing is the important factor? The Piper Tomahawk should be great at flat spins then.
Getting into trouble would have been the better alternative in this case. Hell even if they started shooting at you, that would still have been the better option.So... one more thing to consider.
Brazilian ATC is run by the military, and from past incidents/accidents in that area it looks like you can get into a lot of trouble if you deviate from their instructions.
That might explain the crew's actions.
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Local culture is definitely worth taking into consideration; there has been more than one first officer in SE Asia that watched the captain fly the plane into the ground without saying a word because you just don’t question authority over there. But I would guess this was just icing on a level they had never experienced and didn’t respect. There’s a picture on PPRUNE of an Airbus that landed at their destination that same day with the windshield completely iced over.Easy after the fact.
When an ATC deviation gets you into a very likely loss of job situation, you might tend to minimize the danger that your current icing situation poses.
I'm not saying it's the correct decision, but they did operate in an environment that is not your typical FAA-land.
So they should have all the passenger run up to the front of the plane.Of course it isn't. It was a flat spin. Not recoverable unless you can shift the CG.
The question begs. It seems to me that if a big aircraft, be it an ATR 72, a 737 Max or an Airbus can't get out of a spin yet it can enter a deadly one, as we've seen in the recent past, they would all have serious design faults regarding the CG envelope.
There have been a few recent glider accidents where they spun, they were irrecoverable, and all were due to an improper CG.
People make lots of bad decisions between death or trouble. We all know what it's like to get in trouble, and that we don't like it, so we avoid it like crazy. We don't know what it's like to get dead, so we don't avoid it the same way. Sounds crazy, but it happens all the time.Well, death or “a lot of trouble” …. decisions, decisions….
It wasn't a spin, but it was absolutely a very deep stall - Up to 40 degrees AoA IIRC. It was in a deep enough stall that the computer thought there was no way it was stalled and shut off the stall warnings. When they began to actually think it was a stall and attempt a recovery, it got to where it was just a few degrees above critical AoA and the computer decided maybe it really was stalling and set off all the warnings, so the crew un-did what they'd just done and got it back into a deep stall.AF 447 was not a flat spin, not even a deep stall. They held the 330 in a stall until it was too late to recover.
Deep stall in an aerodynamic sense is when the AOA is high enough that there is insufficient nose-down control power to recover. It's not simply "high AOA." AF447 was not in a deep stall, it was responding to nose-up pitch commands from the cockpit.It wasn't a spin, but it was absolutely a very deep stall - Up to 40 degrees AoA IIRC...
Interesting. Never seen that definition before. Thanks.Deep stall in an aerodynamic sense is when the AOA is high enough that there is insufficient nose-down control power to recover. It's not simply "high AOA." AF447 was not in a deep stall, it was responding to nose-up pitch commands from the cockpit.
Many planes have some unwanted mode of flight, from which normal flight is very difficult to reach.AI agrees:
Which tells me I should not fly in these planes if safety is a concern?
It’s a completely mitigated if operated correctly. Otherwise all airliners can be crashed so by you’re logic just don’t do anything.AI agrees:
Which tells me I should not fly in these planes if safety is a concern?
In a flat spin, with very little control authority due to lack of forward speed and blanketing of tail surfaces, combined with the inertia of two wing-mounted engines far away from the center of rotation, there is likely no accessible recovery mode. Incipient stall recovery needs to be initiated before things develop into a spin. Some GA aircraft (including my AA-5) will not recover from a well-developed flat spin.The video is painful to watch because the spin remains flat throughout, and no apparent effort is made to get out of it (stick in center, push forward, and opposite rudder).
What about using differential thrust?In a flat spin, with very little control authority due to lack of forward speed and blanketing of tail surfaces, combined with the inertia of two wing-mounted engines far away from the center of rotation, there is likely no accessible recovery mode. Incipient stall recovery needs to be initiated before things develop into a spin. Some GA aircraft (including my AA-5) will not recover from a well-developed flat spin.
My understanding from my recent training was that most twins cannot recover from a spin, no matter what you try. Still, recovery procedures did not mention asymmetric thrust, just the regular "power idle/ailerons neutral/nose down/opposite rudder" technique.What about using differential thrust?
Then mash the power levers forward without trimming, and follow up with a trim stall?I wonder if it's a case of not noticing that the autopilot has been adjusting trim to account for a deteriorating condition, e.g. icing, until it hits the trim limit and says "here, you fly now" and hands over a very difficult situation.
That's what I'm thinkingI wonder if it's a case of not noticing that the autopilot has been adjusting trim to account for a deteriorating condition, e.g. icing, until it hits the trim limit and says "here, you fly now" and hands over a very difficult situation.
Wasn't that what happened at Roselawn, which was another ATR IIRC?I wonder if it's a case of not noticing that the autopilot has been adjusting trim to account for a deteriorating condition, e.g. icing, until it hits the trim limit and says "here, you fly now" and hands over a very difficult situation.
No.Wasn't that what happened at Roselawn, which was another ATR IIRC?