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My first guess would be single engine failure with that remaining PT-6 at full power doing the rest.
I don't know what video you found or what you have been drinking.
In this Cessna Caravan, if a single PT-6 fails there is no remaining PT-6 at full power, because it comes from the factory with only one PT-6 installed.
--- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
--- Defend what you say with arguments, not by imposing your credentials ---
I don't know what video you found or what you have been drinking.
In this Cessna Caravan, if a single PT-6 fails there is no remaining PT-6 at full power, because it comes from the factory with only one PT-6 installed.
Just for the record, when I refer to bank angle increasing load factor, I am always talking about level bank. And I am especially talking level bank at 25ft AGL. As for yaw effects, I am referring to coordinated turns.
There was a way out (which obviously was not applied here, not in time anyway):
If you are going faster than the 1G stall speed, you can be stalled but still generating more lift than the airplane's weight. This seems to be the case here (IF the plane was stalled which, again, is just a possibility, not a high probability and even less a fact), judging by how the plane was almost keeping the altitude at a quite high bank angle. The problem is that most of that lift was pointing sideways, not up. If you roll the plane wings level (or just reduce the bank angle a bit) you will have good shuck of that sideways lift re-directed up.
Assuming the plane was partially stalled, doesn't this violate the following:
So yeah, you can have a condition where parts of the wing are stalled, the distribution of lift and drag is asymmetrical, the airplane behaves very different to what you are used to, it keeps rolling to the left even if you stop the aileron input and it rolls even more if you apply anti-roll aileron input, but you are not officially stalled.
That's why when the stall warning (or stall buffeting) goes off, you have to reduce AoA FIRST and stop the warning / buffeting BEFORE attempting to level the wings. with ailerons.
And, of course, with no altitude to give, that's off the table...
The loss of roll damping is most interesting here. As you roll further from wings level in level flight, the roll resistance diminishes and, without reducing the aileron input accordingly, the roll rate increases, in effect resulting in a steeper roll than intended. But even then, at this altitude, any intentional bank angle that would lead you to 70deg is already rodeo material.
[Gabe talking about a way out by leveling the wings and pointing all that sideway-pointing lift more up]/quote]
Assuming the plane was partially stalled, doesn't this violate the following:
[Gabe preaching that you should never touch the ailerons in a stall or close-to-stall situation, reduce AoA first, take care of the ailerons next]
First of all, you don't need to assume that the plane was partially stalled. It could be totally stalled (angle of attack at or beyond peak lift coefficient) and that would still work. Understand that "lift coefficient" is not the same than "lift", which is lift coefficient times speed squared (and other condiments irrelevant for this comment). This plane was flying much faster than the "official" 1G stall speed, judging by the fact that it was almost holding altitude with a 70 deg bank (i.e. with most of the lift pointing sideways. That means that, stalled or not, the lift was quite more than the airplane's weight. As an example, if a plane is going 20% faster than the stall speed (which is still very slow) you would have 44% more lift than the airplane's weight at the stall AoA (peak lift coefficient). So even if you are past the peak and you lost let's say 20% of the lift coefficient compared with the peak, your lift would still be 24% higher than the airplane's weight meaning 1.24 Gs. If you point that up, you would almost immediately convert that slightly negative sink rate into a quicly-increasing positive climb rate. Of course you want to lower the nose as soon as the plane starts to climb so you can regain roll control with the ailerons, otherwise the airplane can keep rolling past wings level and reverse the roll (and then you would need to apply opposite rudder --- oh no, rudder reversals, brace for impact!!! ---). All of that is not easy to do especially if you have never done it before. I understand all the theory of this bout would not trust myself executing it. Having a PhD in the physics of Juggling doesn't make you a good juggler. That's why I advocate for practicing "extreme maneuvering at the edge of the envelope without losing control" and upset recovery (i.e. regain control if lost) as part of a PPL curriculum.
And no, it doesn't violate that.
I should have been more clear. I meant leveling off the plane WITH RUDDER (I forgot to include that little detail). Earlier in the comment I said:
"All the roll authority you lose in the ailerons at a high angle of attack, you gain with the rudder. Rudder is much much more effective at controlling roll close to, at, or beyond the stall than in normal circumstances. Many instructors teach pilots to control yaw with the rudder as part of a stall entry and recovery. I am against that because wrong rudder or too much "correct" rudder can cause a spin. I prefer the concept of do nothing else until you reduce the AoA. Of course that will not help when you are 1 ft above the ground."
And, of course, with no altitude to give, that's off the table...
Yes, lowering the nose was off the table. Kicking right rudder was absolutely not.
The loss of roll damping is most interesting here. As you roll further from wings level in level flight, the roll resistance diminishes and, without reducing the aileron input accordingly, the roll rate increases, in effect resulting in a steeper roll than intended.
Except that the aileron authority is heavily impacted too. What you have is a plane that feels very slow, mushy and unstable in roll. Slow... unless a wing drops. That goes bad very fast.
But even then, at this altitude, any intentional bank angle that would lead you to 70deg is already rodeo material.
Yep.
--- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
--- Defend what you say with arguments, not by imposing your credentials ---
That's why I advocate for practicing "extreme maneuvering at the edge of the envelope without losing control" and upset recovery (i.e. regain control if lost) as part of a PPL curriculum.
But I think the job of instructor pilot might have a high turnover. Pun intended.
Not drinking but I’ve had Covid for days so maybe it’s brain fog.
Have we changed our mask-use procedures?
Praise ATL’s obscure god of the month and stall obsession and who knows what else…WHAT THE PHUGOID IS BEING DISCUSSED HERE.
Stalled or not, a 70 degree bank is not good for climbing out from a go around. Who cares which engine on the Caravan failed!
And, our new credentialed pilot, Boeing Bernty wasn’t crazy for pointing out that there wasn’t an obvious “break in lift”, and that banking like that goes against a lot of fundamentals and given how slow and steady it banked over, it could be from something other than a deliberate pilot input.
One other note de lingues del Espanol y Anglais: “I can’t believe” (Bernty’s comment) is not_always an absolute, definitive proclamation but can be a slightly different “statement of amazement”. “I refuse to believe” vs “unbelievable”.
“I refuse to believe that a fuel gage wire can ignite jet fuel” versus “It’s unbelievable, that football team came back from a 28 point deficit.”
I, too have said, “I can’t believe they just sat there and stalled a CRJ”, I can’t believe they pulled up relentlessly for 35,000 feet” and several others.
Maybe “hard to believe” is better, but cut someone some slack for saying “can’t believe”.
It’s hard to believe an accident like this generated so much discussion- steep banks very often result in some altitude loss and there wasn’t much altitude TO lose here.
Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.
An any-bank exceeding 30deg is not good for climbing out from any takeoff in a commuter airplane.
Fixed. Get to a safe altitude and airspeed before directing lift anywhere but up. A level bank is actually a climbing turn. A climbing bank is a climbing, climbing turn. A 70deg climbing bank on a Caravan might require afterburners. I can’t find sustained turn performance data on the Cessna Caravan (I think for good reason) but it is not an aerobatic-category aircraft, and I suspect on a Caravan a 70deg bank is never associated with climbing.
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