Slipping turns.

[iflyforpie]

I don't do slipping turns anymore really, since Cessna flaps are more than adequate to provide a large controlled decent rate in most circumstances.

I was first taught the slipping turn as bank to the way you are turning and reduce yaw with rudder, but not so much as to stop the turn.

I was then taught by a private pilot on his Taylorcraft to bank away from the direction of turn and over yaw the aircraft with rudder. His reasoning being--and rightly so--that the runway is more visible doing it this way.

When I told my instructor this (many years ago now) he said this was a dangerous maneuver because it was actually a skid.

I define a skid as using bottom rudder (which you aren't in this case) and it is dangerous because in a stall, the bottom wing will stall first, increasing the bank angle.

My question is, what are the risks for doing a slipping turn this way?

Discuss...

[BTD]

That manuever is a skid. If you are yawing the aircraft to turn it, especially against a bank, the ball will be to the outside and that is a skid.

[Hedley]

In a turn:

top rudder is good (slip)
bottom rudder is bad (skid)

If you step on the bottom rudder in a turn, the
yaw produced will slow the inside wing down,
increase it's angle of attack, and potentially
stalling that wing. Meanwhile the outer wing has
sped up because of the yaw and is producing
lots of lift.

This easily results in you being flipped upside
down during your turn onto final, in a spin.
Most people don't like that.

Slips are good, skids are bad.

[FlaplessDork]

In the airplanes I fly I only slip for a x-wind. Planning and flaps do the job much better.

[Invertago]

I'm also too good to need slipping turns anymore

[deflux]

In the airplanes I fly I only slip for a x-wind. Planning and flaps do the job much better.

I agree, but a nice aggressive slipping turn onto final is way more fun

[magyar]

correct me if I'm wrong but turning to final you do want to use some rudder in the direction of turn to keep the ball centered and the airplane co-ordinate, just not to much or over compensate,that would be dangerous.

[brokenwing]

... If you're teaching people how to fly, you should probly be knowledgable and comfortable enough in the aircraft to know when and where to use slipping turns, IMO slipping is great and should be used more, It's alot easier than using flaps, plus if you're a little high, you'll always be able to make your runway in the event of an engine failure. Also, if you keep your circuits nice and tight, your students will likely get more take off and landings in their 1 hour flight.

[Tim]

I was then taught by a private pilot on his Taylorcraft...

that's the problem right there...

[Old Dog Flying]

And if you have an electrical failure and now no flaps...what next? Land in the next county.??? What if no flaps on the aircraft??? Slipping turns are not dangerous unless taught by an instructor who doesn;t understand the procedure. Teach them at altitude using roads for reference then back into the circuit.

And the idiot in the T-Cart is lucky to still be alive.

[iflyforpie]

And the idiot in the T-Cart is lucky to still be alive.

Tell me why based on what I've said. What could happen doing a slipping turn where there is more yaw than bank?

I've done boat turns (full rudder with crossed aileron to keep wings level) for filming purposes and never had a wing even think of dropping. Doing this IMHO is riskier than a slipping turn with more yaw than bank where a wing drop will simply restore wings level.

[Old Dog Flying]

The T-Cart demo is not a "slipping" turn but is a SKIDDING turn.

[iflyforpie]

Nope.

Skidding is using bottom rudder. You are still using top rudder in the T-Cart example.

[BTD]

Nope.

Skidding is using bottom rudder. You are still using top rudder in the T-Cart example.

Nope it is a skidding turn. Bottom rudder is not the only way to do a skidding turn although it is the most common. If you are yawing the aircraft against a bank input to turn it that is a skid. Your example is an awkward skid, and one that most light aircraft couldn't do because they wouldn't have enough rudder authority to overcome the bank in the opposite direction, however it is still a skid.

The ball in your example would be to the outside of the turn, that is a skid.

BTD

[Hedley]

they wouldn't have enough rudder authority to overcome the bank in the opposite direction

I suspect this would only be possible at small angles
of bank, because as the aircraft is banked more and
more, the horizontal component of the yaw produced
by the rudder would become less and less. The vertical
component of the yaw produced by the rudder does not
make the airplane turn.

As a way of understanding this, at 90 degrees of bank,
full top rudder will not make the airplane turn at all - only
keep the nose up. I do this all the time - it's called
knife edge flight, and it's perfectly safe. Easier to do
at faster speeds.

[BTD]

they wouldn't have enough rudder authority to overcome the bank in the opposite direction

I suspect this would only be possible at small angles
of bank, because as the aircraft is banked more and
more, the horizontal component of the yaw produced
by the rudder would become less and less. The vertical
component of the yaw produced by the rudder does not
make the airplane turn.

As a way of understanding this, at 90 degrees of bank,
full top rudder will not make the airplane turn at all - only
keep the nose up. I do this all the time - it's called
knife edge flight, and it's perfectly safe. Easier to do
at faster speeds.

Agreed, however, the original example given was a skid and not a slip.

[iflyforpie]

Looks like it is a battle of semantics.

But nobody has told me any specific danger of maneuvering an aircraft in this manner. Most Cessnas will perform this maneuver quite well because it does not require a large angle of bank.

Why is this 'skid' so dangerous?

[BTD]

Personally I don't think it is quite as dangerous as a usual skid in the direction of the bank.

However, in the example, you are still inducing lots of yaw in the direction of the turn. In a slipping turn you are inducing yaw in the direction away from the turn. If you were to stall in the skid scenerio you have lots of yaw in the direction the airplane is already turning.

Regardless of all of this, if you have passengers I would steer clear of this just from a comfort point of view. Most passengers don't like yaw while straight and level. (think flying along straight inducing yaw and keeping wings level with opposite aileron). Now if you do this while banking away from the desired direction of turn, people won't be too happy.

Its like Nascar designing a race track with the bank of the curves going outward instead of inward, terribly uncomfortable.

My opinion.

BTD

[iflyforpie]

Thank you. That is what I was looking for.

As I said, I rarely do a slipping turn either way (I do carry quite a few passengers, and if I am by myself I use full flaps early on for steep approaches and tight circuits). I was just looking for other opinions on the risks involved that were more than 'it's a skid, so it's dangerous'.

[MichaelP]

A couple of chaps came to me one day to ask me to explain why their Jodel 119 dropped a wing when they slipped it.

I went up with one of them and he was stalling the aircraft on finals... It's good to stall an inch off the ground but not ideal at a hundred feet!

In China we did stalls from a slip as part of the syllabus and the DA40 does a very dramatic wing drop stall from this situation!

Slipping turns in the Citabria are fun and dramatic and safe enough... You must feel your aeroplane and know when the buffetting becomes stall related.

I use slipping turns for landing into a setting sun, landing if there's oil all over your windscreen (or a dead bird perhaps), or if you're flying a Spitfire (dreamer!). I sometimes call "Spitfire finals" if I'm doing a curved approach.

We're required to teach it and I've known a student to fail a PPL flight test because he got confused doing one... Later he did a perfect slip as part of his forced landing exercise probably because it was the right context for doing it!
He did a partial retest and demonstrated to the examiner that he was perfectly able to do a slip even though he'd done likewise on his first flight test as part of the 'PFL'! I thought that a bit unfair.

[hairdo]

In China we did stalls from a slip as part of the syllabus and the DA40 does a very dramatic wing drop stall from this situation!

Hold it in a bit longer and it will give you a fun and more aggressive spin too!

As I said, I rarely do a slipping turn either way (I do carry quite a few passengers, and if I am by myself I use full flaps early on for steep approaches and tight circuits). I was just looking for other opinions on the risks involved that were more than 'it's a skid, so it's dangerous'.

With a descending skidding turn, the inside wing is going slower (more than in a regular descending turn), so it has the potential to stall sooner than expected. What you described to me sounded like a cross-controlled situation, which, if you stall, leads to a more aggressive than normal spin... kinda bad if you are low and slow (ie. approach). Slipping turns, useful for losing alt, seeing forward (I don't know why your Taylorcraft buddy didn't do a simple forward slip). Skidding turns, only use I can think of is for aerial photography.

The way I find that helps me to identify if I am doing a slip vs. a skid is that if the nose is turning the same what that I am pushing on the rudder, then I'm skidding. If I'm pushing on the rudder and the nose isn't moving, then I should be slipping (forward, side slip). If the nose is turning in the opposite direction of my rudder, then I should be slipping. Obviously, you will need rudder for other applications which won't lead to a skid or slip (controlling yaw from a turn entry), but when you are intentionally trying to create a slip or skid, I find the above to help properly identify what you are doing (especially for new students).

My 2cents.