FlyingAccountant
Well-Known Member
Jesus, man...
Pilatus with 7 Aboard Down Off The Coast of NC
- Thread starter Conrad
- Start date
Jesus, man...
BobDDuck
Island Bus Driver
That wouldn't really be a stall then, would it?
knot4u
Repeat Offender
Yes, because it would be intentional doesn't change aerodynamics.
BobDDuck
Island Bus Driver
Not what I was saying. If you recover from a "stall" prior to pusher activation, you aren't actually stalling the airplane. 25.103 (I think... going from memory right now) says that a pusher has to activate within 2 knots of Vsr. That means the nose is coming down prior to the plane reaching Vsr (except in a few accelerated stall scenarios where the mechanism activating the pusher can't keep up) and aren't actually experiencing a full loss of aerodynamic control.
In the past, most training programs taught recovery at the first sign of a stall, which was normally some kind of buffet or system generated stall horn. Those things all happen well before you get close to actually stalling. The pusher is a last ditch system's effort to prevent you from stalling. We are starting to see changes in AQP programs where pilots are required to ignore all those warning (hurray for negative training!) and hold the condition past the pusher and into a "full" stall. On FBW aircraft you normally need some level of flight envelope protection degradation to even make this possible.
knot4u
Repeat Offender
I don't know about current training but I was very familiar with demonstrating an unaccelerated stall, a power on stall (and spins because I'm a glutton for punishment) for my instructor before I went for my PPL checkride. And I've tested plenty of pushers, they don't always work.
ppragman
FLIPY FLAPS!
Pilatus pusher is tested every flight before takeoff (you can’t clear the CAWS panel unless you do). If it breaks you’d know it pretty quick.
It’s really pretty tough to experience a natural stall in the airplane if the pusher is working.
knot4u
Repeat Offender
G-IVs are the same. Sometimes there's an issue with an AOA transmitter, I've changed plenty during MX on airplanes that came in with no related squawks. Wonder why?
Roger Roger
Bottom of the list
I still haven’t seen anything to contradict my original statement about having to have multiple failures AND operating the airplane well outside how you were trained to get a PC-12 into one of those stalls shown in the video.
ppragman
FLIPY FLAPS!
I would be shocked (shocked) if this accident was a stall. Just saying.
Depends I suppose on how you define a "stall" I suppose. As it relates specifically to a PC-12, I can't speak to it. I "died <simulator wise>."
BobDDuck
Island Bus Driver
A stall occurs when Cl max is reached, and a further increase in AOA results in a decrease in lift. I don't think that's really up for re definition. What the point of recovery "from a stall" is, as used in various training programs, is very much definition dependent.
I wasn't trying to redefine, but point out that a stall and its consequence isn't an absolute for every flying situation. It's a post on a thread.
A stall is an aerodynamic condition which occurs when. smooth airflow over the airplane's wings is disrupted, resulting in loss of lift.
<source - google>
ppragman
FLIPY FLAPS!
The Pilatus never has an interruption in smooth airflow if the pusher isn’t overridden.
knot4u
Repeat Offender
Using the word "never" is dumb. I said in a previous post that I've found pushers that don't work during a functional test but will pass the pre-flight check the crew performs. If you think Pilatus figured out to eliminate mechanical failures you should tell everyone how they were able to do it. These airplanes don't operate in a perfect world.
Roger Roger
Bottom of the list
The point isn’t all of that. It’s one or two people attempting as far as I can tell to say that “OMG pilatus bad!” Because of a behavior that only happens if you have cascading failures AND a massive failure of pilot technique. News flash, if you look for deep stall videos you can find ALL KINDS of aircraft that do really interesting stuff if you bypass all the stall protections. Shoot there’s a really popular one of the 717 going inverted during stall testing. And the dude who worked so long on Lears ought to know what happens with those if one of the dozens of little pieces of metal on the leading edge is in the wrong place.
knot4u
Repeat Offender
I never said a Pilatus is a bad airplane. Stuff happens. Regarding Lears, where would you suspect I might've found some of those failures? Do you get out and move the AOA transmitters up and down with the flaps in each position while monitoring the AOA gage and the transmitter position with hydraulic pressure to verify the pusher is working properly before each flight in your Lear? Same thing with a Gulfstream, you as a crew aren't expected nor (normally) are you qualified to run the entire functional check that is done during MX. We do those things for a reason, 98% of the time it works as advertised, but the 2% is why we do it.
Cherokee_Cruiser
Bronteroc
I can't believe a bunch of airline pilots can't even agree on the definition of what a stall is. Wow, and they let you people fly jets?
EVERYONE knows an airplane stalls when the engine isn't getting enough air, energy, fuel, electric spark, fuel starvation, a mechanical failure, or in response to a sudden increase in engine load such as when the pilot releases the clutch too suddenly.
EVERYONE knows an airplane stalls when the engine isn't getting enough air, energy, fuel, electric spark, fuel starvation, a mechanical failure, or in response to a sudden increase in engine load such as when the pilot releases the clutch too suddenly.
Imagine trying to translate the "words" from another language. . . like Hebrew? <new religion?> :stir:
ppragman
FLIPY FLAPS!
Jesus
Wardogg
Meat Popsicle
Did you fly the NG? I have a question.
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