You are in a slipping turn, and you stall....

[SkyHog]

This was a discussion amongst 3 unnamed pilots and myself today (and its been a flashchat discussion in the past as well).

You are turning, lets say left, and you are not holding enough rudder, therefore you are slipping (I had to explain that to avoid discussion about skids, as that is not the question). You could be doing it to lose altitude or possibly because you are lazy and flying uncoordinated.

You keep banking and you hit that magic point where your turn causes the stall speed to rise high enough to meet your current airspeed. You stall. What happens next?

Do you spin? Do your wings roll level like a normal stall? Do you plummet to the ground in a ball of flames and have your wings ripped off at the same time?

The question is: What happens in a slipping turn when you stall?

 

[AdamZ]

well if you can get the engine restarted..... Sorry just had to say it.

 

[jesse]

This was a discussion amongst 3 unnamed pilots and myself today (and its been a flashchat discussion in the past as well).

You are turning, lets say left, and you are not holding enough rudder, therefore you are slipping (I had to explain that to avoid discussion about skids, as that is not the question). You could be doing it to lose altitude or possibly because you are lazy and flying uncoordinated.

You keep banking and you hit that magic point where your turn causes the stall speed to rise high enough to meet your current airspeed. You stall. What happens next?

Do you spin? Do your wings roll level like a normal stall? Do you plummet to the ground in a ball of flames and have your wings ripped off at the same time?

The question is: What happens in a slipping turn when you stall?

Honestly whatever happens must not have been too exciting (in the airplanes I've tried it in) because I've done it several times and all I really remember is the controls losing feeling the nose starting to fall, me going coordinated, and recovering. This has always occurred in a slipping turn with the nose above the horizon.

Keep the nose below the horizon and don't worry about it. I don't care how steep you bank in the turn or how coordinated you are if you keep the nose below the horizon and don't jerk the yoke to your chest you won't be stalling (in any airplane I've flown). I can crank and bank a 172 or Diamond at any altitude and any airspeed as steep as I want as long as I let the nose fall by itself into the turn and don't fight it.

I really wish that instructors and the like would pound into students heads that in most unusual attitudes the reason people get killed is from them pulling on the stick or yoke. You can go as steep as you want and not have an issue. Things don't load up until you pull. A lot of doctors in fast airplanes in instrument conditions could have used the lesson. They get into a nose down situation and see the altimeter unwinding. They have no idea what their attitude is--and they pull. A few seconds later they no longer have wings.

An interesting thing about the Diamond is that in a slipping turn it takes a lot of back pressure on the stick otherwise it'll be pointed straight down in no time. I just always hold enough back pressure to keep the nose pointed down below the horizon at a very respectable angle and the airspeed and controls remain nice and solid. In a 172 neutral elevator input usually delivers a nice nose down angle that is stable.

But everything I wrote here is probably worthless. It's just based on my experience and what I have observed from doing the above. I'm not an aerodynamics expert. I just notice cause and effect. There are quite a few people on this forum that are better qualified to answer the above.

 

[wby0nder]

The question is: What happens in a slipping turn when you stall
?

Depends on the airplane, and momentum on various axis, center of gravity...Mostly the individual airplane.

Usually, but not always, no big deal.

Skids are where you can get into trouble the most.

 

[tonycondon]

like matt said, depends on the aircraft. Chips Extra will spin out of a slip amazingly well, in fact, it seemed to me to spin better out of a slip than a skid!

172 on the other hand, in my experience at least, seems difficult to stall out of a slip.

No one answer is right.

 

[CowboyPilot]

I really wish that instructors and the like would pound into students heads that in most unusual attitudes the reason people get killed is from them pulling on the stick or yoke. You can go as steep as you want and not have an issue. Things don't load up until you pull. A lot of doctors in fast airplanes in instrument conditions could have used the lesson. They get into a nose down situation and see the altimeter unwinding. They have no idea what their attitude is--and they pull. A few seconds later they no longer have wings.

Amen.

But everything I wrote here is probably worthless. It's just based on my experience and what I have observed from doing the above. I'm not an aerodynamics expert. I just notice cause and effect. There are quite a few people on this forum that are better qualified to answer the above.

I've never given much thought to aerodynamics when I found myself in an accidental or inadvertent spin. . . What I gave thought to was "cause and effect" as in I'm pretty sure I know what caused me to be upside down and spinning like a circus top so I better correct it sometime soon."

Never underestimate the importance of your own perception of "cause and effect." It greatly enhances your "seat of the pants" ability which translates into maturity and experience and ability as a pilot.

"Stick & Rudder," the textbook don't do you a helluva lot of good when you get inverted in some Navy jet's jet wash. Understanding and reacting to cause and effect will help you faster and quicker than anything else.

Regards.

-JD

 

[gismo]

like matt said, depends on the aircraft. Chips Extra will spin out of a slip amazingly well, in fact, it seemed to me to spin better out of a slip than a skid!

172 on the other hand, in my experience at least, seems difficult to stall out of a slip.

No one answer is right.

True, but AFaIK any airplane will roll towards wings level at the onset (incipient phase) of a slip induced spin. That gives a lot more time for the reflexes to kick in and prevent an actual spin. One of the biggest differences between airplanes is the response to aileron input in this situation. In a 172, aileron away from the spin direction will delay spin entry but in some planes (this probably includes the extra, I know it includes the Starduster Too and AT-6) holding or worse yet adding aileron towards the inside of the original turn will hasten spin entry.

I can't say for sure but I'd bet that in any of those planes unloading the wings (forward stick) anytime prior to reaching about a 45 degree bank in the opposite direction of the original turn will stop the spin in it's tracks.

 

[poadeleted20]

Generally speaking, if the ball is out of center at the stall, the airplane will yaw in the direction away from the ball. In a slip, that means it goes opposite the bank angle. If the cross-control is big enough (say, full rudder opposite the bank), you can get an interesting "over the top" departure. However, in just about any light single, unless you hold that full rudder through the departure, it will not actually enter a spin. If you simply don't have enough rudder to coordinate the turn (i.e., no rudder, as opposed to opposite rudder), you are, in such a plane, unlikely even to see the "over the top" move, just an easily controllable roll towards level as described above by Lance.

 

[bbchien]

Yah but don't be trying this in a Baron. I have a hard enough time limiting it to a split S, let alone an inverted spin.....

 

[gibbons]

Do you plummet to the ground in a ball of flames and have your wings ripped off at the same time?

This is what always happens to me when I try it. I just hate it when that happens.

Chips Extra will spin out of a slip amazingly well, in fact, it seemed to me to spin better out of a slip than a skid!

Tony, I must have hit it just right because usually it's much harder to get the Extra to spin over-the-top (from a slip) than it is under-the-bottom (from a skid). We'll try it again this March.

If the cross-control is big enough (say, full rudder opposite the bank), you can get an interesting "over the top" departure. However, in just about any light single, unless you hold that full rudder through the departure, it will not actually enter a spin.

I've only really experimented with this in the Pitts and the Extra, but in those two airplanes Ron is exactly right. It takes an almost abusive use of rudder to make the airplane go over-the-top.

 

[jshawley]

If I'm not mistaken, BruceAir put out a video on this subject.

Jim

 

[Dave Krall CFII]

I really wish that instructors and the like would pound into students heads that in most unusual attitudes the reason people get killed is from them pulling on the stick or yoke. You can go as steep as you want and not have an issue. Things don't load up until you pull. A lot of doctors in fast airplanes in instrument conditions could have used the lesson. They get into a nose down situation and see the altimeter unwinding. They have no idea what their attitude is--and they pull. A few seconds later they no longer have wings.

quote]

It's more a matter of pulling the right amount over the correct duration of time in that situation. Situational awareness is great, but not always possible without fairly drastic measures, such as in IMC.

 

[jesse]

It's more a matter of pulling the right amount over the correct duration of time in that situation. Situational awareness is great, but not always possible without fairly drastic measures, such as in IMC.

There are times where pulling *period* is bad. Imagine an attitude about 100 degrees rolled left and 30 degrees nose down. This is the stuff that can easily happen in IMC-- The first thing people want to do is pull because they are pointed down. Couple seconds later and they are dead.

 

[Henning]

This was a discussion amongst 3 unnamed pilots and myself today (and its been a flashchat discussion in the past as well).

You are turning, lets say left, and you are not holding enough rudder, therefore you are slipping (I had to explain that to avoid discussion about skids, as that is not the question). You could be doing it to lose altitude or possibly because you are lazy and flying uncoordinated.

You keep banking and you hit that magic point where your turn causes the stall speed to rise high enough to meet your current airspeed. You stall. What happens next?

Do you spin? Do your wings roll level like a normal stall? Do you plummet to the ground in a ball of flames and have your wings ripped off at the same time?

The question is: What happens in a slipping turn when you stall?

If it's inadvertant (you don't have a bunch of rudder in) in most planes you'll get a yaw and the top wing will break(not physically, aerodynamicaly) and you'll end up nose down ready for stall recovery. Most all modern light planes, you have to work at it to get them to snap. If the rudder aint on the floor, it's not gonna happen. When you get into aerobatic aircraft designed intentionally with low inherent stability, the situation gets different as it does with some warbird.

 

[Nav8tor]

If I'm not mistaken, BruceAir put out a video on this subject.

Jim

http://www.bruceair.com/stall_videos.html

Scroll down about half way.

 

[SkyHog]

Ok, so to sum up the answers: In an Extra 300 (per the video and Tony), a stall from a slipping turn will spin. In most other planes, a stall from a slipping turn is just a stall. But if you don't stall it doesn't matter. And avoiding a stall is as easy as keeping the nose down. That pretty much the sum of the answers here?

Also - a poll is coming next.

 

[gibbons]

Ok, so to sum up the answers: In an Extra 300 (per the video and Tony), a stall from a slipping turn will spin. In most other planes, a stall from a slipping turn is just a stall. But if you don't stall it doesn't matter. And avoiding a stall is as easy as keeping the nose down. That pretty much the sum of the answers here?

Nick,

I might sum it up like this:

A stall from a slip can result in a spin, but in most airplanes the control inputs need to be extreme and the pilot pretty much asleep to hold them in long enough for the wing to come all the way over the top. It is possible, and at low altitude it can be dangerous.

A stall from a skid is abrupt and attention-getting, and is very likely to result in a spin. The wing is already low and it doesn't take much to tuck it under the airplane.

It is not difficult to recover from a spin under-the-bottom if the pilot is expecting it and has the proper training and plenty of altitude. For the untrained pilot of a 172 (for example) with full fuel and four adults, low and slow and skidding the base to final, the shock and sensory overload of the under-the-bottom spin usually don't subside until the point of impact.

If you're really interested in how all this works, I highly suggest getting some spin training. Chandler, AZ and Boulder City, NV both have instructors who can provide excellent training. It's eye opening and a lot of fun.

 

[jesse]

In most other planes, a stall from a slipping turn is just a stall. But if you don't stall it doesn't matter. And avoiding a stall is as easy as keeping the nose down. That pretty much the sum of the answers here?

I can say I haven't ever had a stall from a slipping turn in a 172, Archer, or Diamond DA-20 do anything exciting. These have all been done very nose high with an obvious expectation of the stall coming on.

In any of these airplanes keeping the nose pointed down a reasonable amount will not cause a stall.

As you know from flying with me I tend to do a lot of slips. I do them because they're fun.

 

[jesse]

Nick this should help you understand what will happen in an aircraft like the 172 you were flying. Keep in mind that every airplane will have different stall/slip/spin characteristics. I decided the best way to explain this was to go up and do it.

Here is my video of a turning slip forced into a stall in a Cessna 172:

http://www.youtube.com/watch?v=5xDxj_CRfqY

As you can tell more or less the airplane will just mush towards the ground. It is actually more tricky to hold the 172 in a normal stall as you must constantly correct for one wing wanting to drop. If you do a turning slipping stall you just hold the controls and spin around dropping like a rock. The nose will slowly bob up and down around the horizon. Control input for the slip was full right rudder, almost full aileron, and yoke held back to the stops. I held the yoke to the stops method throughout that entire stall demonstration. Sometimes the 172 will drop enough that it recovers enough airspeed to go back up as you can see. I really wish that instructors would go over this stuff with their students in each airplane they fly so that they are not afraid of certain parts of the flight envelope.

Edit: It looks like youtube is sucking right now. If that link doesn't start working soon I'll upload somewhere else

 

[SkyHog]

Thanks Jesse. That is what I figured would happen. Cool to see it in video form!

 

[Michael]

Keep the nose below the horizon and don't worry about it. I don't care how steep you bank in the turn or how coordinated you are if you keep the nose below the horizon and don't jerk the yoke to your chest you won't be stalling (in any airplane I've flown). I can crank and bank a 172 or Diamond at any altitude and any airspeed as steep as I want as long as I let the nose fall by itself into the turn and don't fight it.

I really wish that instructors and the like would pound into students heads that in most unusual attitudes the reason people get killed is from them pulling on the stick or yoke. You can go as steep as you want and not have an issue. Things don't load up until you pull.

Why do you think you will not stall in a turn, Only when you pull up? What does your POH say about load factors increasing the stall speed in turns? Do you know what a 45* or even 60* bank at 60 or 70 kts will do with full fuel and 3 passengers in a light plane?

 

[jesse]

Why do you think you will not stall in a turn, Only when you pull up? What does your POH say about load factors increasing the stall speed in turns? Do you know what a 45* or even 60* bank at 60 or 70 kts will do with full fuel and 3 passengers in a light plane?

Load will go up by pulling on the controls. If you do not pull on the controls the nose will naturally fall into the turn and your airspeed will not get to the point of stalling. Of course you will not be holding altitude either--You have to pull to hold altitude.

Pulling causes load which causes the stall or worse yet--no more wings. Could you stall in a turn without pulling on the stick? Maybe--but for the most part it's pretty safe to say if you keep it unloaded and don't pull you'll be fine.

 

[poadeleted20]

Could you stall in a turn without pulling on the stick?

Light singles are designed so that even with full nose-up trim, they will not exceed critical AOA power-off without positive aft stick input -- not sure about power-on. However, if you haven't done anything silly with the trim, and it hasn't run away nose up (as electric trims have been known to do), a light single airplane will not stall without some help from the pilot. They may not all recover from a stall hands off, but absent a malfunction, they will not go into one that way. Generally speaking, you really have to work at it to cause a light single-engine airplane to stall and/or spin.

 

[Michael]

Generally speaking, you really have to work at it to cause a light single-engine airplane to stall and/or spin.

How do you explain all those "base to final" accidents? were they all skidding too slow while pulling on the yoke? did they turn to steep to slow?

I am really interested to know what you think. I am always uneasy about steep turns in the pattern.

 

[jesse]

How do you explain all those "base to final" accidents? were they all skidding too slow while pulling on the yoke? did they turn to steep to slow?

They are on a left base.. They might even be a bit slow.. Looks like they are going to overshoot final..They turn real steep. They aren't used to this steep of a turn and if they didn't pull on the yoke they'd be WAY more nose down than they are used to. So they pull a bit--they are trying to hurry the turn--so they start pressing on the left rudder.... They are slow, skidding, and pulling...and now they are dead.

 

[SkyHog]

I think that's exactly what happens. Overshoot final, cheat with the inner rudder. Pull back to tighten the turn. Boom, recipe for disaster.

 

[flyingcheesehead]

How do you explain all those "base to final" accidents? were they all skidding too slow while pulling on the yoke? did they turn to steep to slow?

I am really interested to know what you think. I am always uneasy about steep turns in the pattern.

That's actually part of the problem.

Pilot (who doesn't know better) accidentally overshoots final - Tailwind on base, maybe. They've been told not to exceed x degrees of bank in the pattern, so instead they add some rudder. Being in a bank, the rudder also points the nose down, so they pull back to compensate and/or tighten the turn, and round and round they go...

I'd say that the CFI's need to do a better job of explaining WHY you don't want to turn too steep in the pattern (increased load factor means increased stall speed, which may approach the speeds used in the pattern) rather than just giving an arbitrary number. Then, they need to discuss the risks involved in uncoordinated flight (spins) and what causes all the accidents.

Frankly, I think a stall in the pattern due to turning "too steep" is probably a lot more recoverable than a spin due to skidding while trying to NOT turn "too steep."

 

[cwyckham]

Why do you think you will not stall in a turn, Only when you pull up? What does your POH say about load factors increasing the stall speed in turns? Do you know what a 45* or even 60* bank at 60 or 70 kts will do with full fuel and 3 passengers in a light plane?

As others have said, a 60 degree bank only increases the stall speed in a level turn. You'll pull 2 g in a 60 degree bank, therefore increasing your stall speed, if you do it without losing altitude. However, if you allow the aircraft to lose altitude, you don't have to pull any extra g at all, so the stall speed stays the same.

When you're in a slipping turn, you're trying hard to lose altitude, so there's no need to pull on the yoke and increase your g load. People generally get into trouble when they're feeling like the ground's getting too close and they start pulling. That's especially a problem for gliders or powered aircraft who've lost power. Those same people are nervous about banking too much so low, so they're skidding and pulling which is a bad combination. People seldom slip and pull.

Chris

 

[Henning]

How do you explain all those "base to final" accidents? were they all skidding too slow while pulling on the yoke? did they turn to steep to slow?

I am really interested to know what you think. I am always uneasy about steep turns in the pattern.

Yep, that's pretty much it. Students afraid to put the wing down into the appropriate bank and forcing the turn with the rudder. Toughest thing to get across is getting that wing down turning base to final is safer than keeping it flat.

 

[Dave Krall CFII]

Nick this should help you understand what will happen in an aircraft like the 172 you were flying. Keep in mind that every airplane will have different stall/slip/spin characteristics. I decided the best way to explain this was to go up and do it.

Here is my video of a turning slip forced into a stall in a Cessna 172:

http://www.youtube.com/watch?v=5xDxj_CRfqY

As you can tell more or less the airplane will just mush towards the ground. It is actually more tricky to hold the 172 in a normal stall as you must constantly correct for one wing wanting to drop. If you do a turning slipping stall you just hold the controls and spin around dropping like a rock. The nose will slowly bob up and down around the horizon. Control input for the slip was full right rudder, almost full aileron, and yoke held back to the stops. I held the yoke to the stops method throughout that entire stall demonstration. Sometimes the 172 will drop enough that it recovers enough airspeed to go back up as you can see. I really wish that instructors would go over this stuff with their students in each airplane they fly so that they are not afraid of certain parts of the flight envelope.

Edit: It looks like youtube is sucking right now. If that link doesn't start working soon I'll upload somewhere else

It's a good video but I turned it off halfway through because not only could I not hear (understand) what you were saying, the constant, loud, stall horn was too annoying.

 

[Dave Krall CFII]

Load will go up by pulling on the controls. If you do not pull on the controls the nose will naturally fall into the turn and your airspeed will not get to the point of stalling. Of course you will not be holding altitude either--You have to pull to hold altitude.

Pulling causes load which causes the stall or worse yet--no more wings. Could you stall in a turn without pulling on the stick? Maybe--but for the most part it's pretty safe to say if you keep it unloaded and don't pull you'll be fine.

Considering things like tumbling gyros and instrument lag time, how does one recover from unusual attitudes in IMC on the simulator that are randomly generated either by the SIM or another person, while the SIM pilot looks away from the panel, then takes over the unusual attitude recovery?

 

[jesse]

It's a good video but I turned it off halfway through because not only could I not hear (understand) what you were saying, the constant, loud, stall horn was too annoying.

Turn your volume down

Most of it was just me doing my best to give it an input involving a slip that would make it spin or do something exciting--there was absolutely no chance that it was going to do it. I held the 172 in a stall until I no longer felt it was safe to do as I had already burned through 4,000 ft of altitude.

 

[Dave Krall CFII]

Turn your volume down .

I can't find the stall horn volume control on this Dell... stupid computer box.


.[/quote]

 

[tonycondon]

im sure Mac's have that option. Maybe they added it to Windows Vista.

 

[Chache]

I can't find the stall horn volume control on this Dell... stupid computer box.


.

It's the disguised one, in the front center of the box, with the green light...B)



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