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Ed Cesnalis

Avoiding inadvertent spins

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I'm reading pilots saying they avoid slips on final to avoid spins.

I'm prone to slip but I do avoid skids thinking spins enter from skids not slips.

Are slips on final protection / margin or are they additional spin risk simply because they are uncoordinated?

Obviously I think they are protection not risk.

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I am working on a sport pilot glider add on. Just this past weekend flying with a glider instructor, he ask me to do a stall in a skidding turn. I did, but just as soon as the nose started to brake I initiated the recovery. I didn't let it go far enough to suit him, so he did one letting it break into the spin entry. No big issue, because I have done spins on many occasions.

Back when I did my CFI 25+ years ago the instructor ask me to do a stall in a slip. I held full up elevator, full rudder, and full opposite aileron while the airplane just shook and shuddered. It never did brake letting the nose drop.

Another thing that sticks in my mind even though it didn't happen to me is hearing about a Mooney. Just doing simple straight ahead full stalls it likes to break and spin.

I think the take away is that each airplane is different and you need to know the individual habits of the airplane you are flying. Personally I am not afraid of slips. I use them and teach using them. They are a valuable tool to have in your pilots bag of tricks.

Sometime soon I plan on taking my 14 year old son who recently soloed in a glider out and do some skidding turn stalls. Just so he will know what happens if you mess up.

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7 minutes ago, Tom Baker said:

I plan on taking my 14 year old son who recently soloed in a glider out and do some skidding turn stalls. Just so he will know what happens if you mess up.

Your a good dad

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1 hour ago, Ed Cesnalis said:

Here's the take-away from that:  don't use rudder to tighten a turn.

Though if you're using aileron to tighten the turn, DO use rudder to stay coordinated!

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2 hours ago, Ed Cesnalis said:

Your a good dad

I started flying young, and had to wait to solo. Part of my pre solo training included spins, both left and right. We also did them from accelerated stalls both into the turn and over the top.

I consider myself lucky to have had that training.

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I frequently do forward slips if I've misjudged my height and end up coming into a short field too high or the wind is stronger than I thought and this is preventing my CT from loosing altitude fast enough for the upcoming runway.  Maybe I've got a false sense of security but I've never had any surprises doing this.  My CTSW always seems to be docile and predictable and provides me with good directional control doing slips.  I usually use full flaps for landing and I do watch my speed and keep it well above stall.  When I remove pressure from the stick and rudder, my CT immediately responds and returns to the attitude it is trimmed for.

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Slips are not a problem, I do them regularly at speeds down to 48kt to adjust my descent rate.  I will slip to the pedal stops most of the time; I will always do this instead of adding more flaps, it just feels like I have more control and can adjust or take out the slip when I'm on the glide path I want to be on.

If you don't retrim or add stick back pressure the airplane will pick up speed when slipping due to the gravity assist.  This makes it pretty hard to get the airplane down to stall speed in a slip, you'd have to have the nose abnormally high.  If you did start the spin sequence, the low wing would have to come all the way over the top to roll into the spin.  This gives a lot of time to get off the rudder before the wing comes over. 

The issue with skids is that the low wing rolls out from under you and you are IN the spin before you have a chance to react.  At pattern altitude you probably can't recover it, so you'd have to be johnny on the spot with that red handle...

I'm with Ed and Dick here, skids are dangerous on the base to final, slips not so much.

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A good way to refer is a 'proper slip' vs a skid because a skid is a slip too.

A proper slip could lead to a snap roll in the pattern but not as likely as a skid leading to a spin and with more time to react. 

 

Inadvertent snap rolls seem to come with a rapid rudder input like the student that was slipping on final and got a tired leg and just removed her foot for the snap entry.

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55 minutes ago, Ed Cesnalis said:

A good way to refer is a 'proper slip' vs a skid because a skid is a slip too.

Most pilots view them as opposites.  They are both uncoordinated flight, but a skid is not a slip.  A slip is inadequate or opposite rudder for the direction of the turn, a skid is too much rudder into the same side as the turn.

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Depends on where you get your definitions:

 

 

11.4  Skids

 

11.4.1  Definition and Explanation

 

The term skid denotes a particular type of slip that occurs when the airplane is in a bank and the uncoordinated airflow is coming from the side with the raised wing. Typically this happens because you have tried to speed up a turn using “bottom rudder”, that is, pressing the rudder pedal on the same side as the lowered wing.

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30 minutes ago, FlyingMonkey said:

So... where DID that definition come from??  

https://www.av8n.com/how/htm/snaps.html

other gem: Beware: The inclinometer ball is often referred to as the slip/skid instrument, but that is another misnomer. It measures inclination, not slip. As we shall see in section 17.1.4, it is quite possible for the airplane to be inclined but not slipping. To repeat: there is no good way to determine the slip angle without a slip string.

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Hold it guys......I need to get my popcorn and come back to read when I get some time.  This is definitely information overload!   :o

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From the FAA Airplane Flying Handbook:  "A slip occurs when the bank angle of an airplane is too steep for the existing rate of turn."  Hard to see how that can also be a skid.  

Aircraft Spruce will sell you an "Inclinometer" for $54.  It is a curved glass tube filled with liquid in which a solid round sphere is free to move under the influence of gravity and inertial (centrifugal) forces.  You are all very familiar with this instrument.  Aircraft Spruce also calls these instruments "Bank Indicators" and "Slip Indicators".  

 

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