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Chr1s1968
10-25-2008, 06:38 AM
Hi
I have just started flying and am not content to start on easy (teaches you bad habits!!). I have manged to get into a stall spin several times and want to ask

1) what factors cause a stall spin?

and more importantly

2) How does one get out of a stall spin?

Chr1s1968
10-25-2008, 06:38 AM
Hi
I have just started flying and am not content to start on easy (teaches you bad habits!!). I have manged to get into a stall spin several times and want to ask

1) what factors cause a stall spin?

and more importantly

2) How does one get out of a stall spin?

K_Freddie
10-25-2008, 06:54 AM
link1 (http://adamone.rchomepage.com/index2.htm)
link2 (http://en.wikipedia.org/wiki/Spin_(flight)) There are some good links at the bottom of this page - nice graphic PDF docs
Link3 -Some PDF file (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/a2fdf912342e575786256ca20061e343/$FILE/AC61-67C.pdf)
Link4 - Ye olde Nuggets Guide (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/9121094645)

Google 'stall spin' = lots of info
http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Owlsphone
10-25-2008, 07:49 AM
A spin starts when one wing is stalled more than the other.

Spin recovery techniques can be different for some aircraft. Some planes are even impossible to recover. The general rule to get out of a spin is, power idle, neutralize elevator and ailerons, and use rudder in the opposite direction of the spin.

Chr1s1968
10-25-2008, 09:43 AM
Thanks K Freddie and Owlsphone. Got into spin this afternoon after my first campaign kill(Have been playing in the nursery school last two days!!) and managed to get out thanks.

Stingray333
10-25-2008, 10:07 AM
Dropping the flaps sometimes helps me recover from a spin

It can be good to learn the spin characteristics of your plane by spinning the plane on purpose with the so called "auto rotation" technique: quickly pull up hard and apply full rudder. This is also called a snap-roll. This just helps get a feel for the spin characteristics of your plane, and help with recovery, etc.

If your flying in a single player setting you can also cheat and use the auto-pilot, which will recover you from anything including the dreaded flat spin.

Stingray

crucislancer
10-25-2008, 10:58 AM
IIRC, the P-39 needs some extra attention when getting out of a spin, though I don't fly it that much so I don't recall what you need to do.

M_Gunz
10-25-2008, 11:35 AM
If the plane is in slip when it stalls then you will spin.

Keep the ball centered in normal flight and you won't spin.

Keep the wings level at very low speed flight and you probably won't spin.

Don't push into stall and you won't spin.

Xiolablu3
10-25-2008, 01:11 PM
Most often new pilots stall and spin because they try to perform a too violent manouvre with not enough speed.

If you turn too tight without the required speed, you will stall and spin.

M_Gunz
10-25-2008, 02:16 PM
I stall and spin when I fixate on the target, forget to watch how the plane is flying and get
greedy for angles. The thing is that -when- I do it, I know how it happened!

K_Freddie
10-25-2008, 02:32 PM
One can yank the stick, but you bring it back about 10-20% from it's maximum very quickly. This has the nice effect of putting you on the stall envelope very fast, and hold it there. From here it's purely rudder control. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

TX-EcoDragon
10-25-2008, 07:14 PM
1) A stall is caused by exceeding the critical angle of attack - in other words, pulling too much on the stick may lead to airflow separation over the wings.

A spin happens when a stall is aggravated in some way to produce a yawing component. If this yawing component is not stopped, or opposed, and roll and yaw are coupled (ie left roll, left yaw), then a spin may develop.



2) In IL-2, the best way is to avoid pulling so hard in the first place - listen to the changes in slipstream noise - and look for the headshake - these things indicate that you are at a high angle of attack, and nearing the stall. In quick missions, it's a wise idea to load up a flight at high altitude, and practice a few of these pulls - paying attention to the visual and auditory cues you are given that lead up to the stall.

Assuming you DO stall, and if a wing starts to drop (the first sign that you may be heading towards a spin) when you see the wing drop, apply opposite rudder as quickly as possible, and apply it fully. Also pop the stick forward to lower the angle of attack.



<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
If the plane is in slip when it stalls then you will spin. </div></BLOCKQUOTE>


Well, technically a slip is spin resistant . . .stall while skidding however, and around you go.

There is no yaw to roll coupling in a slip, so when you stall, it will be more benign than when you have yaw to roll coupled. . .many aircraft will actually have their anti-spin characteristics improved by slipping, even compared to coordinated flight, and rather than spin they will mush along straight ahead while in a stalled slip, or they will spiral somewhat in the direction of the applied rudder, but so slowly as to provide plenty of time to recover from the stall before autorotation commences.

In the sim the difference between a slip vs skid on spin development isn't as obvious as in real life - but it still happens to degree in IL-2 as well, so you have a bit of a buffer before a spin initiates if you are slipping.


The best thing to practice in IL-2 is not developed spin recovery (though that's good to practice too), but rather snap roll recovery. . .most of the time a player enters a spin after and acellerated stall - this leads to a snap roll if the stall is skidded. Wait a moment and the snap becomes a standard spin. If you react quickly to the initiation of the snap roll by FULL opposite rudder and a quick forward jab of the stick (assuming a +G stall anyway) you will stop the snap roll quickly, and before a spin develops, which is more difficult to recover from, and saps more of your altitude and airspeed.

M_Gunz
10-25-2008, 07:29 PM
And if the ball isn't centered when you stall while going straight?

TX-EcoDragon
10-25-2008, 07:43 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
And if the ball isn't centered when you stall while going straight? </div></BLOCKQUOTE>

Well, as said above - if you are skidding, you will spin. Coordinated, or in a slip, you generally wont. When you say "going straight" do you mean wings level? You can transition into a slip from straight and level flight and maintain the previous flight path - however at this point the nose is not pointed along this flight path. . .but you may still be "going straight".

As some like to say, the "ball is scared" and will go to the wing that won't drop. . .if you are in a slip, the ball will be on the low wing. Since the high wing will drop, and this drop will restore a wings level attitude before yaw and roll become coupled, and things get better before they get worse. If skidding, on the other hand, the ball will be on the high side of the high wing, and the low wing will drop. . . it will drop quickly, and since it's the low wing, the flight attitude will only get worse, quickly rolling through inverted and entering the spin.

buzzsaw1939
10-25-2008, 08:42 PM
I'm waiting for some body to ask whats the difference between a slip and a skid?

Just to save the trouble, see a car going through a banked turn on ice, if the rear end goes high, he is skidding, if it goes low, he's slipping.

Stingray333
10-25-2008, 08:51 PM
I was going to ask, but thought better of it, lest I receive the receiving end of an "RTFM-n00b" lashing

In my mind skidding is flying at the the same altitude relatively straight, but the noise doesn't point in the direction of travel due to the rudder.

In slipping, a wing is dipped, altitude is being lost, and again the noise isn't pointed in the direction of travel due to the rudder

I know I am missing something here,

Stingray

buzzsaw1939
10-25-2008, 08:57 PM
I always taught that if your flying stright and level, and the ball isn't, your skidding eather way!

M_Gunz
10-25-2008, 09:39 PM
It's the slip ball so I thought the word was slip.

The condition is common with many players.

BTW I do know in turns when you oversteer it's skidding and when you understeer it's slipping.
And now it is told that slipping, you get more drag but less chance of a spin than in skid.

Well, if I keep the ball centered then I only stall since 4.0x and never spin -- until if I
keep the stick back so far the ball shoots to one side and around she goes!

buzzsaw1939
10-25-2008, 10:17 PM
I used to joke with my students, when you want to go up, pull the stick back, when you want to go down, hold the stick back! http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

K_Freddie
10-26-2008, 03:34 AM
In some IL2 planes that have heavy torque (the radials), If you try centre the ball while in a high-g turn this will induce a violent spin. Not sure if this is a game flaw (the slip ball position that is) but I think the torque effect shifts the centre to one side - about a balls width http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Crikey2008
10-27-2008, 09:21 PM
Please comment.

a slip is centrifugal (towards the inside of the turning circle) and is controlled by input
For example, the direction of slip can be controlled by wing down and opposite rudder (creating a side slip).

a skid is a centripetal (force in the direction of the outside of the turning circle) and is generally uncontrolled until control input brings the aircraft out of its skid.

Skid conditions (manufactured under slight but fast turning moments) may operate even if you're attempting to fly straight.
The same with slip since you may keep the nose going in the direction you want by applying sufficent opposite rudder.

The P-39 flat spins with it's nose down; a result (as noted above) of roll being coupled to yaw while it's centre of gravity is forward of its centre of lift. It's behind engine keeps that equilibrium state once its entered into it.

TX-EcoDragon
10-28-2008, 02:24 AM
Slip: rate of turn is insufficient relative to horizontal component of lift. The ground track of the aircraft can remain constant as yaw is opposed by the horizontal component of lift.
A slip may or may not involve a turn. In either case, the pilot/passengers will feel themselves being pushed to the low wing/inside of a turn. (Note: In a coordinated level turn, the piot/passengers will not feel any lateral forces, they will feel Gs in the vertical axis, so their martinis won't spill off the tray tables no matter the bank angle.)

Skid: rate of turn is excessive relative to horizontal component of lift. The ground track of the aircraft will arc in the direction of the excessive rudder input, since yaw is unopposed. The rudder drives the turn, the pilot/passengers will feel themselves being pushed to the outside of the turn (towards the high wing in a skidded turn).

Here's a video of one of the applications of a slip: http://www.youtube.com/watch?v=I96s0VLB_rU

Even though this is "cross controlled" for the reasons previously stated, it's a rather safe maneuver at low altitude where it is regulalrly employed for handling a crosswind as seen in the above link. It is also often used to increase the rate of descent/steepen the glidepath on landing approach to get down quicker, clear obstacles near the runway, this happens because as the aircraft is yawed, more of the side area of the aircraft is expozed to the relative wind, which causes an increase in drag. Lastly, slips are also used to see the runway when approaching to land since many tailwheel aircraft are blind in the forward direction.

Oh and of course they may be used, along with skids, in combat to throw off the aim of the guy shootin at ya!

M_Gunz
10-28-2008, 03:03 AM
So the Greek guy who built the gymbal movement flight sim seat should be controlling tilt
from slip ball data instead of roll angle data, to make down to the side the player should
feel. That would be great because you'd not have to check the ball nearly as often, you'd
be able to feel what an unmoving chair won't. I hope he sees this....

na85
10-28-2008, 06:50 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Crikey2008:
Please comment.

a slip is centrifugal (towards the inside of the turning circle) and is controlled by input
For example, the direction of slip can be controlled by wing down and opposite rudder (creating a side slip).

a skid is a centripetal (force in the direction of the outside of the turning circle) and is generally uncontrolled until control input brings the aircraft out of its skid.

Skid conditions (manufactured under slight but fast turning moments) may operate even if you're attempting to fly straight.
The same with slip since you may keep the nose going in the direction you want by applying sufficent opposite rudder.

The P-39 flat spins with it's nose down; a result (as noted above) of roll being coupled to yaw while it's centre of gravity is forward of its centre of lift. It's behind engine keeps that equilibrium state once its entered into it. </div></BLOCKQUOTE>

Centrifugal = "center fleeing" = outwards
Centripetal = "center liking" = inwards

Crikey2008
10-28-2008, 06:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by na85:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Crikey2008:
Please comment.

a slip is centrifugal (towards the inside of the turning circle) and is controlled by input
For example, the direction of slip can be controlled by wing down and opposite rudder (creating a side slip).

a skid is a centripetal (force in the direction of the outside of the turning circle) and is generally uncontrolled until control input brings the aircraft out of its skid.

Skid conditions (manufactured under slight but fast turning moments) may operate even if you're attempting to fly straight.
The same with slip since you may keep the nose going in the direction you want by applying sufficent opposite rudder.

The P-39 flat spins with it's nose down; a result (as noted above) of roll being coupled to yaw while it's centre of gravity is forward of its centre of lift. It's behind engine keeps that equilibrium state once its entered into it. </div></BLOCKQUOTE>

Centrifugal = "center fleeing" = outwards
Centripetal = "center liking" = inwards </div></BLOCKQUOTE>

Well spotted http://forums.ubi.com/images/smilies/clap.gif

You've forced some further observations:

The centrifugal and centripetal forces do not exist in reality.
However, we feel them when we are in a non-inertial system. Someone sitting on a merry-go-round has to apply force inwards to stop from flying off to the outside; and that is centrifugal force as you point out.

In a similar manner, when an aircraft is in a skid outwards its outer wing will develop more lift and fly the aircraft against the original skid direction; or the pilot will apply control input to force the aircraft back into the turning circle to obtain the same result quicker.
This is why I called the skid centripetal in nature because equilibrium lies in the centripetal direction towards the inside of the turning circle, Similarly, in a side slip opposite rudder is used to counteract the lift force moving the aircraft into the turning circle (onw wing down, the other up). In that sense I called the slip centifugal because that is the direction of the rudder force used to maintain a straight line of flight.

Understanding stall from the perspective of how the aircraft is destined to react against these forces whether naturally or from pilot input is the key to understanding how to handle stall flight.

In general terms there is more room and more time to handle stall if these forces are entered into with sensitivity.

I'm not sure when stall warnings began to be installed into aircraft but clearly there is a felt need for today's aircraft. Perhaps that is an indication of the caution needed around stall in both slow and fast aircraft.

M_Gunz
10-28-2008, 07:31 PM
As pointed out above, in a skid (too much rudder for the bank) you will feel pushed outwards.
Consider turning on a flat road in a car you will feel the same, pushed outwards.

Too little rudder in the turn and you get slip.

Looked at from the other way, too much bank makes slip and too little bank (flat turn ala DrI)
makes skid.

The big bonus present: slip in turn is spin resistant! Skid in turn is spin prone.

Maybe I can make a chair that will rock sideways up to 5 or 10 degrees then I won't need to
depend on the ball to know what I would IRL. But it would maybe not work online as devicelink
online is limited.

WTE_Galway
10-28-2008, 09:49 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:

Maybe I can make a chair that will rock sideways up to 5 or 10 degrees then I won't need to
depend on the ball to know what I would IRL. </div></BLOCKQUOTE>

Back in my real world flight training the instructor would regularly cover the ball and get you to fly co-ordinated by lateral force and sound. Actually the key to fine adjustment was sound. An aircraft in even slight slip or skid makes a distinctive louder air rush sound that is unique for every plane and you learn to pick it up instinctively.

TX-EcoDragon
10-29-2008, 01:43 AM
You don't even need to look at the ball.

If looking left or right over a wing, as you start to roll use rudder input to make the wing move vertically, rather than slicing forwards or backwards. If you put your feet on the floor and briskly roll into a medium or steep bank you should see the wing slice forward and backwards when you roll (if the adverse yaw is properly modeled in that aircraft/sim) you can then cancel out this forward/backward motion of the wing with rudder and if you do this well, the ball will be centered the whole time while you are doing these wing rocks. Alternatively, the same thing can be done when looking forward over the nose, if you make the spinner/nose rotate on point as you roll, rather than letting the nose move left or right as you roll. If the nose makes a happy face, that's not good. You want to see it draw this"." not this "U".

Of course this only works while rolling, and not once the bank is established, but generally, once the bank is established, the aileron input is close enough to neutral that very little rudder is needed to maintain coordination relative to how much was required when the ailerons were deflected. You can pin the nose on a spot some amount above or below the horizon and if you don't let the nose slice left or right (in a bank this will be up or down), you should be pretty well coordinated. . .and of course you can verify this with a glance at "the ball".

M_Gunz
10-29-2008, 02:19 AM
It's a d@mn sight more difficult in a sim where your frame of reference is the view though.

Not letting the nose rise or fall from initial pointing when turning though does work in
sim-land to at least some degree and I go back over 10 years on that though I didn't know
it was that good an indicator, only roughly. Well, live and learn!

ADD: hey if we get that sound mod that Eco posted about earlier then a lot of improvement
should come about in the way players fly IL2.