Question about steep turns

JakePilot

JakePilot

Filing Flight Plan
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~Jake~
Hi people my name is Jake, i am new here, currently working on my CFI ratings.
Someone asked me a question in my school and i didn't really know the answer.
the question is: Is it possible to make Steep Turns above 45 degrees bank during Slow Flight maneuver?

thanks for the answers :)
 
The question isn't being posed properly, when you say during the slow flight maneuver do you mean the regular airspeed for straight and level slow flight? If that's the case then no because stall speed increases with bank angle. Now, if you were to calculate the stall speed for the bank angle in question, then in theory you would be doing a steep turn in "slow flight."

However, having said all of that, I think I know what you're asking and the answer is no.
 
Maciej said:
The question isn't being posed properly, when you say during the slow flight maneuver do you mean the regular airspeed for straight and level slow flight? If that's the case then no because stall speed increases with bank angle. Now, if you were to calculate the stall speed for the bank angle in question, then in theory you would be doing a steep turn in "slow flight."

However, having said all of that, I think I know what you're asking and the answer is no.
Click to expand...

yes what i meant is straight and level slow flight.
thanks for the answer.
 
In my opinion, no because in slow flight, you are already at the minimum controllable airspeed. You turns should be standard rate AT MOST or you risk stalling. I would not risk a 30* turn during slow flight as the bank angle increases your stall speed, so you are about to stall, possibly spin.
 
Here you go, just came across this.

bank-172.jpg
 
technically to stall the airplane you need to exceed the critical angel of attack, on a slow flight you are close to the critical angle of attack, during bank your horizontal component of lift is reduced which force you to use more elevator pressure to keep the airplane at the same altitude and therefore increase your angle of attack, i think its possible if you do it super smoothly without abrupt elevator pressure as long as you don't exceed critical angle of attack.
that's my theory, i am not sure that's why i am asking :)
 
Yes, but the speed for slow flight in a bank will be faster than straight and level slow flight. Just do 45 degrees of bank right on the edge of a stall. That is slow flight. 60 degrees might be doable, but it will be more difficult. At least that is my take.
 
You can do a steep turn, but you'll need to full power, lose altitude and pick up airspeed in the process of the turn. Think Emergency turn, Box Canyon turn, Wing overs etc (without climbing portion), i.e. descending turns. You will be unable to remain at same altitude due to slow flight entry
 
If you do "real" slow flight -- minimum controllable airspeed -- you can't do it at constant altitude.

If you do wimp slow flight -- "first indication," you might.

If you release the yoke, you also might do it, but you won't maintain altitude.

That "stall speed increases" thing seems to be pretty widely misunderstood. It applies to level flight.
 
Capt. Geoffrey Thorpe said:
Nice picture.

To bad that it is complete nonsense.
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The stall speed in a maneuver (VSM) increases as the square root of the load factor (LF). Assuming a stall speed of 50 knots in level flight, at 60 degrees angle of bank the stall speed will increase by the square root of the load factor +2 (√2), which is approx 1.4. This means that, at 60 degrees angle of bank, the stall speed is increased by 40% to 70 knots. What part of this is nonsense? It's all science.
 
Walboy said:
I wouldn't increase speed in a box canyon turn as the radius of the turn increases with an increase in speed. The best thing to do is to slow down and might be a good reason to practice steep turns at a slow airpseed.
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Agreed, but from the CFI stand-point, you wouldn't be doing steep turns during slow flight manu's. you'll need some performance and power to pull through a true steep turn in level flight. We do 60 degrees as steep for private standards in Australia
 
Slow in relation to what?

Once that's defined, then we can answer the question correctly.
 
EdFred said:
Slow in relation to what?

Once that's defined, then we can answer the question correctly.
Click to expand...
Right and, level or not level, with a descent option that changes the answer again.
 
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.
 
I've never flown a single-engine airplane that couldn't maintain altitude in a 45-degree bank with intermittent stall horn/stall buffet.

Not required for an certificate or rating, obviously, but a good confidence maneuver.
 
Above 45 degrees your G factor also increases: 1.41G at 45deg, 2G at 60 deg, 5.76G at 80deg. That means you also have to fly faster by the square root of the load factor to not stall. So for example if your stall speed level is 60, it's 71 at 45deg, 85 at 60g, and already 144 at 80deg.
 
Walboy said:
I wouldn't increase speed in a box canyon turn as the radius of the turn increases with an increase in speed. The best thing to do is to slow down and might be a good reason to practice steep turns at a slow airpseed.
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IIRC, the math says the tightest level turn is at Va & max load factor, I.e., at the edge of stall.
 
MauleSkinner said:
IIRC, the math says the tightest level turn is at Va & max load factor, I.e., at the edge of stall.
Click to expand...

I'd wager I could hammerhead a 180 with a tighter lateral distance than that. ;)
 
MauleSkinner said:
IIRC, the math says the tightest level turn is at Va & max load factor, I.e., at the edge of stall.
Click to expand...
That's corner speed and it gives you best rate, not radius.
 
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.
Click to expand...

Stall horn it is a slow flight, the horn doesn't mean you are stalled, stall horn just gives you an indication that you will stall if you aggravate your angel of attack because the airflow starts to separate from the wing, but the airplane is still flying, its not stalled.

So my question was if you can make a steep turn (at least 45 degrees) while you maintain minimum speed ( on the edge of the stall), nobody provided a clear answer yet unfortunately but thanks for trying to help :)
still waiting for the genius to solve this issue.
 
Maciej said:
The stall speed in a maneuver (VSM) increases as the square root of the load factor (LF). Assuming a stall speed of 50 knots in level flight, at 60 degrees angle of bank the stall speed will increase by the square root of the load factor +2 (√2), which is approx 1.4. This means that, at 60 degrees angle of bank, the stall speed is increased by 40% to 70 knots. What part of this is nonsense? It's all science.
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Stall speed increases as the square root of the load factor. Yes, it's science.

60 degrees of bank causes a load factor of 1.4ish? Nonsense.
 
Also, anything above 60 degrees is illegal in a normal category aircraft, without chutes. So there's that.

Capt. Geoffrey Thorpe said:
Stall speed increases as the square root of the load factor. Yes, it's science.

60 degrees of bank causes a load factor of 1.4ish? Nonsense.
Click to expand...

No, it's not nonsense. This is why people die in the classic tight-base-to-turn final-with-lots-of-rudder-to-help-it-come-around skidding turn.

Angle-Of-Bank-VS-Stall-Speed.gif
 
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JakePilot said:
So my question was if you can make a steep turn (at least 45 degrees) while you maintain minimum speed ( on the edge of the stall), nobody provided a clear answer yet unfortunately but thanks for trying to help :)
still waiting for the genius to solve this issue.
Click to expand...
No, your question was "Is it possible to make Steep Turns above 45 degrees during a Slow Flight maneuver?"
The clear answer is "yes". What are you intending to ask?
 
Yes, you can do a slow flight 45 degree turn. But, you won't be able to do it at the speed for straight and level. If you do, you'll stall. You have to define a new slow flight speed for the intended turn and bank angle you want to use. So, if you add a little margin, probably around 20% in speed on a 45 degree turn, you would be able to do it.

I should qualify this by saying that it is possible to do a descending steep turn where load factor does not increase, in that instant, the stall speed does not go up. But you can only do that if you trade some altitude.
 
MauleSkinner said:
No, your question was "Is it possible to make Steep Turns above 45 degrees during a Slow Flight maneuver?"
The clear answer is "yes". What are you intending to ask?
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That's the same question exactly, just people here trying to find different variations for slow flight, so i tried to ask my question in a different variation too,
yes is not a clear answer my friend, unless you can prove that, i believe its possible but i cannot prove it for 100% , that's why i am asking
 
stratobee said:
Yes, you can do a slow flight 45 degree turn. But, you won't be able to do it at the speed for straight and level. If you do, you'll stall. You have to define a new slow flight speed for the intended turn and bank angle you want to use. So, if you add a little margin, probably around 20% in speed on a 45 degree turn, you would be able to do it.
Click to expand...

that's what i was looking for.
ty my friend!
 
JakePilot said:
That's the same question exactly, just people here trying to find different variations for slow flight, so i tried to ask my question in a different variation too,
yes is not a clear answer my friend, unless you can prove that, i believe its possible but i cannot prove it for 100% , that's why i am asking
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I'd say several people have answered that question already.

One thing to consider as a CFI...just like in this instance, you may need to phrase the same answer Several different ways before a particular student understands it.:)
 
MauleSkinner said:
According to http://www.csgnetwork.com/aircraftturninfocalc.html ,turn radius goes down substantially with increased bank angle when flying a knot or two above the stall speed for that bank angle.

What reduces it more?
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Your post above referenced maximum load factor, now you are referencing maximum bank angle. To answer your question, it will be at a speed less than that which provides sufficient airspeed to achieve maximum load factor.
 
Cooter143 said:
Your post above referenced maximum load factor, now you are referencing maximum bank angle. To answer your question, it will be at a speed less than that which provides sufficient airspeed for maximum load factor.
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How do you increase load factor in a level turn if you don't increase bank angle?

can you provide a concrete example of "a speed less than that which provides sufficient airspeed for maximum load factor"?
 
MauleSkinner said:
How do you increase load factor in a level turn if you don't increase bank angle?

can you provide a concrete example of "a speed less than that which provides sufficient airspeed for maximum load factor"?
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I'm a little confused as to what you're asking, but bank angle and load factor are independent. You can turn without banking. The question is about the size of the circle, and the time it takes you to move around the circle.
 
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?
 
stratobee said:
No, it's not nonsense. This is why people die in the classic tight-base-to-turn final-with-lots-of-rudder-to-help-it-come-around skidding turn.
Click to expand...
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?
 
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?
Click to expand...

Semantics are important, but the OP's original question was about BANKING over 45 degrees in STEEP TURNS.
 
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?
Click to expand...
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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