Question about steep turns

I don't know if it uploaded, but here is a generic example. Notice the radius band left of the airspeed that corresponds to Maximum Load Factor. The turn radius is the dotted line slanting up from right to left.
 

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Capt. Geoffrey Thorpe said:
They are watching the bank (which does not cause a stall) and not watching the speed / load factor (which does cause a stall).
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I must be misreading you. This is the first time I've run into someone arguing that banking doesn't increase load factor, when the mathematics and physics that say it does have been established and understood--and proven--for a long, long time.

Skidding a descending turn leads to stall/spin when the airplane gets slow and the inside wing stalls first simply because that inside wing is flying at a slightly higher AoA than the outside wing.
 
Dan Thomas said:
I must be misreading you. This is the first time I've run into someone arguing that banking doesn't increase load factor, when the mathematics and physics that say it does have been established and understood--and proven--for a long, long time.

Skidding a descending turn leads to stall/spin when the airplane gets slow and the inside wing stalls first simply because that inside wing is flying at a slightly higher AoA than the outside wing.
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I could be mistaken but I think he is pointing out, that bank itself is not connected to load factor. You can complete an aileron roll without any Gs. You can also roll 45 degrees and if you don't pull the aircraft into a turn, there is no load factor. The load factor is only a product of how much you pull, not how much bank there is.
 
Cooter143 said:
Minimum radius will be along the lift limit line at a point left of the maximum load factor. I think you are confusing rate and radius. Let me try to post an image that might help.

Edit: I can't get get it to upload, I'll try again in another post.
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So...in a normal category airplane with a 3.8-g load limit, what bank angle/airspeed/load factor combination will result in the minimum turn radius at a constant altitude with a coordinated turn? Just to try to prevent another abstract post, let's assume a Vs of 40 knots for the configuration to be used.
 
MauleSkinner said:
So...in a normal category airplane with a 3.8-g load limit, what bank angle/airspeed/load factor combination will result in the minimum turn radius at a constant altitude with a coordinated turn?
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I have no idea, it depends on the airplane. In the example I uploaded, it is around 130kts. Maximum rate, which occurs at maximum load factor occurs at 410kts. Turn radius will change with nose position in relation to the horizon. What point are you trying to make and why are you asking? It's easier if you just say what you're trying to get at.
 
I'm trying to get you to show how you can achieve a smaller turn radius than 157 feet in a constant altitude, coordinated turn for an airplane with a 40-knot Vs.
 
MauleSkinner said:
I'm trying to get you to show how you can achieve a smaller turn radius than 157 feet in a constant altitude, coordinated turn for an airplane with a 40-knot Vs.
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Why?
 
Capt. Geoffrey Thorpe said:
They die in the classic tight-base-to-turn final-with-lots-of-rudder-to-help-it-come-around skidding turn because they are using rudder to skid around rather than banking because they believe that shallow banks keep you safe. And that is just wrong. They are watching the bank (which does not cause a stall) and not watching the speed / load factor (which does cause a stall).

Again, how does banking increase the load factor? Explain the actual physics.

If BANKING increases the load factor, what is the load factor at 90 degrees of bank? And, how would it be possible to roll through 90 degrees?
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MauleSkinner said:
Ok...let's also assume a coordinated turn. What airspeed/bank/g-loading combination gives you the smallest possible turn radius at a constant altitude?
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a11p0106-figure-02.png

interesting figure from http://www.tsb.gc.ca/eng/rapports-reports/aviation/2011/a11p0106/a11p0106.asp
from a discussion of canyon turns
'relative to small training aircraft' (not for actual use)
 
Cajun_Flyer said:
Was someone doing sharp s-turns on final, by chance?
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Snort! LOL. Glad I didn't have a soda when I read that. So you're enjoying a particularly entertaining and strange meltdown/troll on Facebook this week, too? Hahaha. Wowzers.

saddletramp said:
Interesting point. If your review the new ACS for private pilot slow flight is the slowest speed you can fly WITHOUT the activating the stall warning. In that case you probably can do a 45 degree bank. On my recent CFI reinstatement ride the examiner asked me the definition of slow flight. I responded that slow flight was the minimum speed you could fly while maintaining altitude & not stalling. He had me review the new ACS (which I had with me) & sure enough it's the slowest speed you can fly without activating the the stall warner. I'm befuddled why the FAA would make that change & also find it very difficult in my 182 with a STOL kit to set up slow flight & not hear the horn.
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Rod Machado has been on the warpath about this change for months now. It's pretty retarded. (And yes I said retarded because it's well past the stupid mark on the scale...)

Cooter143 said:
Your a low-life, grow up.
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* You're

:)
 
capt. you are arguing with people that really do not understand aerodynamics. or they are not explaining what they are trying to say. you and I both know that load factor is only increased with bank in a level turn, unload the wing and and you can bank as much as you want and not increase load factor. If bank increases load factor how come a barrel roll is only 1 g?. your right, the graphic said nothing about level flight, so it is wrong.

bob
 
If I'm in a box canyon, I', not worried about stopping at 45 degrees.
 
unsafervguy said:
capt. you are arguing with people that really do not understand aerodynamics. or they are not explaining what they are trying to say. you and I both know that load factor is only increased with bank in a level turn, unload the wing and and you can bank as much as you want and not increase load factor. If bank increases load factor how come a barrel roll is only 1 g?. your right, the graphic said nothing about level flight, so it is wrong.

bob
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but...but....but....that's not what my pilot mill CFI told me!!!!!
 
exncsurfer said:
a11p0106-figure-02.png

interesting figure from http://www.tsb.gc.ca/eng/rapports-reports/aviation/2011/a11p0106/a11p0106.asp
from a discussion of canyon turns
'relative to small training aircraft' (not for actual use)
Click to expand...

The problem with this graphic is that if you're caught in a box canyon, the first natural thing people try is to climb, and if they're not prepared to plan an "out" at all times, they're usually only going to attempt the turn *after* they've already bled off any excess airspeed that they had.

It's really common to have to push the nose DOWN to execute a canyon escape maneuver in order to maintain a safe flying speed. So you'll be both at the "more likely to stall" end of that chart, but also already into the "more likely to hit terrain" end of it as well.

The terrain scale of that chart is information made of pure unobtanium because it depends on your AGL prior to starting the maneuver.
 
unsafervguy said:
capt. you are arguing with people that really do not understand aerodynamics. or they are not explaining what they are trying to say. you and I both know that load factor is only increased with bank in a level turn, unload the wing and and you can bank as much as you want and not increase load factor. If bank increases load factor how come a barrel roll is only 1 g?. your right, the graphic said nothing about level flight, so it is wrong.

bob
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Yes. We are told over and over that bank increases stall speed, but the increase in stall speed has nothing to do with bank angle. Stall speed increases when you increase load factor. Load factor increases when you pull back for whatever reason. What's the load factor in a 60 degree turn? It depends on how hard you pull. You can pull 1 G, you can pull 1.4 G you can pull 2 G. What is the stall speed?

How does it improve safety to mislead people with half truths and myths? It's the old stall / spin on the turn to final - we tell people to keep the bank shallow to stay safe. Result? Dead pilots. How about telling them to not load the wings and let the nose drop? Would that fix the skidding turn that is made to avoid the dreaded bank? Why not teach the real facts?

Avoid stalls by not pulling back and loading up. That works. That is real. Avoid a stall by not banking - that doesn't work. That's not real. As was pointed out, it is simple science.
 
denverpilot said:
The problem with this graphic is that if you're caught in a box canyon, the first natural thing people try is to climb, and if they're not prepared to plan an "out" at all times, they're usually only going to attempt the turn *after* they've already bled off any excess airspeed that they had.

It's really common to have to push the nose DOWN to execute a canyon escape maneuver in order to maintain a safe flying speed. So you'll be both at the "more likely to stall" end of that chart, but also already into the "more likely to hit terrain" end of it as well.

The terrain scale of that chart is information made of pure unobtanium because it depends on your AGL prior to starting the maneuver.
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I didn't think they were going for a distance scale on the terrain, they were just saying the wider your turn the more likely you are to run out of room in any given terrain.
 
MauleSkinner said:
You claimed I was wrong, but you're unwilling and/or unable to demonstrate that.

What would you call it?
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You seem incapable of engaging in a profitable discussion, but I'll recap to explain, then I'm done. I didn't say you were wrong, but you obviously are disagreeable to correction. You gave the definition of a minimum rate turn and implied it was the definition of minimum radius. I pointed out that minimum radius doesn't necessarily occur at maximum load factor, but maximum rate does and I supplied an example indicating that. Min radius can occur across a band of airspeeds. Just because you plug in numbers to make it some cases doesn't mean it's true in all.
 
So plug in numbers where it doesn't work.

Oh, that's right...you can't.

Have a nice day.
 
Capt. Geoffrey Thorpe said:
Yes. We are told over and over that bank increases stall speed, but the increase in stall speed has nothing to do with bank angle. Stall speed increases when you increase load factor. Load factor increases when you pull back for whatever reason. What's the load factor in a 60 degree turn? It depends on how hard you pull. You can pull 1 G, you can pull 1.4 G you can pull 2 G. What is the stall speed?

How does it improve safety to mislead people with half truths and myths? It's the old stall / spin on the turn to final - we tell people to keep the bank shallow to stay safe. Result? Dead pilots. How about telling them to not load the wings and let the nose drop? Would that fix the skidding turn that is made to avoid the dreaded bank? Why not teach the real facts?

Avoid stalls by not pulling back and loading up. That works. That is real. Avoid a stall by not banking - that doesn't work. That's not real. As was pointed out, it is simple science.
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Doesn't it depend on what you're trying to do? If you bank and don't pull, you're not really turning are you. If the point was to turn, you're not accomplishing that if you don't pull, right?
 
exncsurfer said:
Doesn't it depend on what you're trying to do? If you bank and don't pull, you're not really turning are you. If the point was to turn, you're not accomplishing that if you don't pull, right?
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again, basic aerodynamics. bank and you get a vertical and horizontal component of lift. if you do not pull the aircraft turns from the horizontal component and descends do to the loss of vertical component of lift. if you let it descend, the load factor does not increase, but the aircraft turns.

bob
 
MauleSkinner said:
So plug in numbers where it doesn't work.

Oh, that's right...you can't.

Have a nice day.
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How does the diagram I uploaded not show that? Minimum radius occurs below max load factor by a significant margin.
 
unsafervguy said:
again, basic aerodynamics. bank and you get a vertical and horizontal component of lift. if you do not pull the aircraft turns from the horizontal component and descends do to the loss of vertical component of lift. if you let it descend, the load factor does not increase, but the aircraft turns.

bob
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Wouldn't your pulling add to both components? So you'd get less turn and less lift. Would your turn be any tighter descending 45 deg. pulling no Gs or 30 deg level?
 
extreme 90 deg. bank with no G
220px-%22On_the_straight_and_level%22_%281063897748%29.jpg
 
It doesn't plug in the numbers.
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??????? 130kts min radius/ 410kts Va
 
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exncsurfer said:
I didn't think they were going for a distance scale on the terrain, they were just saying the wider your turn the more likely you are to run out of room in any given terrain.
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Which isn't always true in real canyons. And gives a false sense that wider is always worse.

I'm just pointing out that the chart has severe limitations that don't match actual mountain flying.

Carry on with the whole circle-jerk about it. If someone wants to come see a canyon where a tighter escape turn is worse than a wider one, I know a couple. Come on up. We'll go peek at them when it's nice and cool out.
 
MauleSkinner said:
So that's your idea of a coordinated turn.

Have a nice day.
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Look man, you haven't offered anything of substance. I have no problem being wrong, but I've supplied a hard example of my point and I have others. You're not even really disagreeing with what I'm saying, you just keep saying "prove it". Obstinance isn't an argument, so point out where I'm wrong. Better yet, never mind. I think I will just have a nice day.:)
 
denverpilot said:
Which isn't always true in real canyons. And gives a false sense that wider is always worse.

I'm just pointing out that the chart has severe limitations that don't match actual mountain flying.

Carry on with the whole circle-jerk about it. If someone wants to come see a canyon where a tighter escape turn is worse than a wider one, I know a couple. Come on up. We'll go peek at them when it's nice and cool out.
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Yea, not trying to argue either, just thought it was an interesting figure of a couple radius bank combinations. Wasn't really looking at the canyon usefulness. :)
 
exncsurfer said:
Yea, not trying to argue either, just thought it was an interesting figure of a couple radius bank combinations. Wasn't really looking at the canyon usefulness. :)
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Yeah. It does show the speed relationship nicely.

Bank angle makes a much smaller overall change than groundspeed for radius.
 
denverpilot said:
Snort! LOL. Glad I didn't have a soda when I read that. So you're enjoying a particularly entertaining and strange meltdown/troll on Facebook this week, too? Hahaha. Wowzers.
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Guess I'm jaded, as I assumed that since the guy who started this thread was new and his question sure sounded familiar, maybe he was KT.
 
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