Common myth I been noticing among pilots

[msmspilot]

I would humbly caution everyone that GA training aircraft have different stall/spin characteristics (in respect to slip/skids,etc) than other aircraft such as big engined warbirds, swept wing jets, etc.

Oh, I would certainly agree to that. We're all talking about a very small subset of airplanes that were designed to be stall/spin resistant (to varying degrees) and to have VERY tame stall/spin characteristics when you get them to stall.

I had someone tell me once that you have not stalled an airplane until you stall a T-6 out of the top of a loop.

 

[roundout]

Possibly out of rig, you failed to mention what series 172. If you still cant get it to stall this is another one to file in the "your're doing it wrong" box...

I believe it was an M but I can't remember. Several of us did try to figure out exactly what was going on, though we shied from anything more aggressive than normal power off stalls, power on stalls, and accelerated stalls in various flap and power settings. Our concern was that if it was out of whack enough to resist entering a stall, it might be just as resistant to recovering from one.

I suppose if that qualifies me as a puss then I gladly will wear the title. Too much to live for, not enough to be gained by proving I could one-up a 40 year old twisted, thrice-or-more-wrecked trainer.

 

[TUCKnTRUCK]

According to some on here, you're stalled in any forward slip with power idle because you're not maintaining altitude.

No, because in that example you have decreased the angle of attack, and you no longer have balanced forces. The stall thread you refer to is diffrent, because you can not increase the aoa further, and the current aoa does not produce sufficient lift to maintain altitude, therefore you are stalled.

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[KSCessnaDriver]

Pretty much what 22L said. You can stall anything if you try hard enough. Hell, a friggin kite will hammerhead. Sort of.

Boris, I'll give you 10 hours of dual in what I fly if you can figure out a way to stall it.

 

[TwoTwoLeft]

Blow-up-dolls don't count...

 

[msmspilot]

No, because in that example you have decreased the angle of attack, and you no longer have balanced forces. The stall thread you refer to is diffrent, because you can not increase the aoa further, and the current aoa does not produce sufficient lift to maintain altitude, therefore you are stalled.

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Be careful with that phraseology. If he's in a steady state descent (constant rate of descent), then the forces have to be balanced even if he's not maintaining altitude. If they weren't balanced, his rate of descent would be either increasing or decreasing.

At this point I'll really jump off the deep end, and try to get myself in trouble, but just because your current AOA dosen't create sufficient lift to maintain altitude doesn't mean you're stalled (a zero AOA probably won't maintain altitude either), and just because you're stalled doesn't necessarily mean you can't increase AOA. We define the stall as when you exceed the critical AOA, but the wing is at least partially stalled long before that point, and you can wind up in a "mush" that is a high AOA that is unable to maintain altitude, but the stall hasn't broken yet.

I realize that thus far we've talked about small, straight wing airplanes, but look at the Air France flight that crashed in the Atlantic a couple of years ago. The report showed that they were varying the AOA greatly but never got it unstalled. You can create a similar situation in a 172, especially when near max gross on a hot day. I have seen days where with an instructor, student, and about 3/4 fuel, a poor little 172 couldn't maintain altitude in slow flight. You have to look at your criteria for a stall, but we were sitting with the stall horn blaring, airspeed actually below the white arc, in a 200ish ft/min descent. Were we stalled? The only way out was to reduce angle of attack and increase airspeed. While the wing wasn't fully stalled, it was stalled enough.

Maybe I haven't dug too deep a grave here.

 

[TUCKnTRUCK]

Be careful with that phraseology. If he's in a steady state descent (constant rate of descent), then the forces have to be balanced even if he's not maintaining altitude. If they weren't balanced, his rate of descent would be either increasing or decreasing.

At this point I'll really jump off the deep end, and try to get myself in trouble, but just because your current AOA dosen't create sufficient lift to maintain altitude doesn't mean you're stalled (a zero AOA probably won't maintain altitude either), and just because you're stalled doesn't necessarily mean you can't increase AOA. We define the stall as when you exceed the critical AOA, but the wing is at least partially stalled long before that point, and you can wind up in a "mush" that is a high AOA that is unable to maintain altitude, but the stall hasn't broken yet.

I realize that thus far we've talked about small, straight wing airplanes, but look at the Air France flight that crashed in the Atlantic a couple of years ago. The report showed that they were varying the AOA greatly but never got it unstalled. You can create a similar situation in a 172, especially when near max gross on a hot day. I have seen days where with an instructor, student, and about 3/4 fuel, a poor little 172 couldn't maintain altitude in slow flight. You have to look at your criteria for a stall, but we were sitting with the stall horn blaring, airspeed actually below the white arc, in a 200ish ft/min descent. Were we stalled? The only way out was to reduce angle of attack and increase airspeed. While the wing wasn't fully stalled, it was stalled enough.

Maybe I haven't dug too deep a grave here.

I was referring to a previous thread, in which the airplane wouldn't "break" with full up elevator. That was why I was referring to not being able to increase the aoa further. Aoa is not necessarily pitch dependent, and a stall doesn't need to break to be a stall in a check ride.

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[msmspilot]

I was referring to a previous thread, in which the airplane wouldn't "break" with full up elevator. That was why I was referring to not being able to increase the aoa further. Aoa is not necessarily pitch dependent, and a stall doesn't need to break to be a stall in a check ride.

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Opps... typed all that for nothing... :concern:

 

[shdw]

Will you spin? Why does everyone think that you will go in an instant spin if you stall doing a forward slip?

Yes, I've personally experienced it during basic aerobatic training in a Cap 10B. Except we never held the controls after it snapped onto it's back, thus a spin never developed. Anyway, full slip inputs with enough wing down and it just fell. But, with not enough wing down the rudder had the authority to flip you on your back in just under (what felt like) a half a second. A quite disorienting experience I sure never want to have at 500 feet!

The moral of this above story is to keep the wing sufficiently low when slipping in aircraft with strong rudder authority. Doing this should keep you out of danger. Experiment at altitude.

Moving on, in trainer A/C I've never been able to mimic these results. Might it be possible, sure. Likely, I highly doubt it. A slip is an inherently stable aerodynamic configuration. I.E. You're stalled with the A/C wanting to spin toward the low wing, but the application of top wing rudder is proper to recover/stop a spin in that direction; a stable condition. A skid, as already mentioned is a whole different animal.

Skids are the type of cross controlled stall you should be scared of. And they come to bite us during base turn to final after overshooting the runway. The pilot pulls back to try and catch it, cheats with a little rudder into the turn, and before you know it they are dangerously slow in a skidding turn. In this configuration, rudder is being applied in the direction the aircraft wishes to spin; an unstable condition.

Hope that helps.

 

[mshunter]

Yes, I've personally experienced it during basic aerobatic training in a Cap 10B. Except we never held the controls after it snapped onto it's back, thus a spin never developed. Anyway, full slip inputs with enough wing down and it just fell. But, with not enough wing down the rudder had the authority to flip you on your back in just under (what felt like) a half a second. A quite disorienting experience I sure never want to have at 500 feet!

The moral of this above story is to keep the wing sufficiently low when slipping in aircraft with strong rudder authority. Doing this should keep you out of danger. Experiment at altitude.

Moving on, in trainer A/C I've never been able to mimic these results. Might it be possible, sure. Likely, I highly doubt it. A slip is an inherently stable aerodynamic configuration. I.E. You're stalled with the A/C wanting to spin toward the low wing, but the application of top wing rudder is proper to recover/stop a spin in that direction; a stable condition. A skid, as already mentioned is a whole different animal.

Skids are the type of cross controlled stall you should be scared of. And they come to bite us during base turn to final after overshooting the runway. The pilot pulls back to try and catch it, cheats with a little rudder into the turn, and before you know it they are dangerously slow in a skidding turn. In this configuration, rudder is being applied in the direction the aircraft wishes to spin; an unstable condition.

Hope that helps.

HOLLY CRAP! Where have you been dude!

 

[shdw]

Haha hey buddy long time! I've been surfing still, just not replying. I think this is the second reply in 6ish months. I was rubbed the wrong way with how things went down with tgray many months back, so I took a break from replying and just surf mostly now. Reading this 12 topic single thread brings back so many memories though. I couldn't help myself!!!

Are you still teaching? I'm always on aim, feel free to IM me sometime and catch up bud. And holy jesus man, 5k posts now? Remember the race to 1,000!? You still owe me a beer I reckon.

 

[mshunter]

Haha hey buddy long time! I've been surfing still, just not replying. I think this is the second reply in 6ish months. I was rubbed the wrong way with how things went down with tgray many months back, so I took a break from replying and just surf mostly now. Reading this 12 topic single thread brings back so many memories though. I couldn't help myself!!!

Are you still teaching? I'm always on aim, feel free to IM me sometime and catch up bud. And holy jesus man, 5k posts now? Remember the race to 1,000!? You still owe me a beer I reckon.

Aww crap, you remember that! I still watch the perpetual bad auto pilot every once in a while. 5k posts happens when you are sitting at a FBO waiting for a passenger, or waitng for the next call for some contract work.

 

[gotWXdagain]

I was referring to a previous thread, in which the airplane wouldn't "break" with full up elevator. That was why I was referring to not being able to increase the aoa further. Aoa is not necessarily pitch dependent, and a stall doesn't need to break to be a stall in a check ride.

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You sir need to pay a visit to a wind tunnel.