Slip Restrictions

[Tom]

I have been flying my PA 18-150 for about 18 months. I'm getting to the point of considering my technique up to about average, probably not any better than that. Flying last night with an instructor/friend, he suggested more aggressive slips. The manual is pretty skimpy on that topic.

1) Are there any slip restrictions on the PA 18?
2) Any restriction with partial or full flaps?
3) If slipping aggressively, what speeds do some of you try to maintain:
a. no flaps
b. one notch
c. full flaps
4) Are there any other considerations that I have not mentioned?

The instructor that checked me out originally suggested moderate slips with no flaps but nothing beyond that recommendation.

Tom

 

[Flying Dave]

I don't think there are any restrictions on slipping. Not sure about slips with side windows and doors open. I used to do it in all flap configurations. As for an airspeed, remember that it will be inaccurate due to the relative wind direction change at the pitot tube. As you get to know your airplane, you will know when you are to slow or fast by feel and sound. Go out and practice full slips with an instructor at slow airspeeds with some altitude beneath you and learn what your airplane likes/dislikes.

DE

 

[cubunltd]

I agree with Flyingdave. Learn your own airplane with an instructor. I've slipped with full flaps and doors and windows open. The airspeed is inaccurate but Start off around 60mph and experiment at altitude.

John

 

[cubscout]

I daresay, probably 80% of my Supercub landings were from slips, for one reason or another. Initially, almost direct crosswinds in a 105 Special, and subsequently mild crosswinds, but with a 200' rope trailing, and wanting to clear the fence. After the first few thousand landings, I started to get OK at this.

Flyingdave and Cubunlmtd are correct, no published restriction here. The key is flying the correct PITCH ATTITUDE, since the indicated airspeed is useless; plus, if you're under 200' AGL your head should be totally out of the cockpit. Learn what it looks and feels like, and you'll do good landings.

With more than about 10 knots crosswind component, I like to touch down on the "back" side of the upwind mainwheel, hold off the downwind mainwheel, then plant the tailwheel gently, and be quick on the rudder in the transition.

Other types behave differently, but this has been OK on Supercubs, Champs and Scouts.

But that's just my experience, your actual results may vary. Do what works out for you.

Happy Landings! Cubscout

 

[Bill Rusk]

Definition of a full slip is when the top rudder is at the stop. Ie full rudder. Aileron as necessary to keep it going straight or if a turning slip aileron as required.

Bill

 

[bob turner]

We measured and timed slips - if the door and window are open, and face down, the slip is just shy of twice as effective in terms of angle and vertical speed. That's on a no-flap cub. I never timed it on a Cub with flaps, but with the 60 degree flap setting there didn't seem to be any adverse effect. Of course, with those flaps, who needs a slip?

 

[Tom Jones]

I've never had a problem slipping very agressively. Rudder on the stop, aileron to suit to control the descent rate. Max bank is when the elevator will just barely keep the nose from falling through - you'll run out of rudder before you run out of aileron. All flap configurations (although usually full flaps), doors and windows open or closed.

It's pretty windy slipping toward an open door though. I usually slip to the left, away from the door if it's open and the wind direction allows.

If you really want an elevator ride, try a full flap, max bank, full slip with floats! Just don't try it low the first few times...

 

[Christina Young]

Of course, with those flaps, who needs a slip?

Different combinations of airspeed & slips are taught at Andover as one of the techniques for short field landings over 100 ft obstacle, holding the slip all the way into ground effect (if there is any at your airspeed!) and cushioning the landing with a touch of power. Always with full flaps. I found this quite fun and exhilarating!

 

[ground loop]

Full flaps, full slip into ground effect with thrustline mod is tough to beat for short landing over an obstacle. This is where the thrustline mod shines in my humble opinion!

 

[54tw]

I couldn't find a restriction against slipping with flaps in the Super Cub AOM. As others recommend, with an instructor start out at altitude to check out handling characteristics then perform the pattern work.

If you look very closely at the following photo you may see the amount of rudder deflection in this slip w/full flaps. What appears to be vertical wire off the vertical stab is actually the upper rudder in profile.

http://sparky.supercub.org/photopost/showphoto.php?photo=2019&size=big&cat=500&page=1

 

[JP]

My instructor taught me to slip agressively--full deflection of the rudder and aileron as needed. You can have a surprising amount of up elevator, but don't test the edges of that close to the ground. Have your instructor explore that with you.

I have no flaps on my -11. It's a pretty clean airplane so I like to slip a lot once I'm sure I've got the runway made. Remember to slip nose into the wind and have a blast! Slips are just too much fun and an essential part of the joys of cub flying.

 

[Tom]

Slips

Thanks to all of you who took time to respond to my question on slip restrictions. As soon as the weather clears a bit, I am anxious to explore these slips further (with an instructor and plenty of altitude). It sounds as though I have been a bit conservative.

Thanks again,

Tom

 

[JP]

Be careful.....full slips are wonderfully addictive! :lol:

 

[scubber]

Our PA-18 came from Lock Haven with a C-90, therefore no flaps. When the engine was upgraded to a 135 a few years ago . . the budget ran out . . and flaps weren't added. . . but VG's were. With the "90" and in full slip (to the stops) you would fell vibration in the stick when you were getting too slow. Now I fell the same vibration at full slip but . . it is still rock solid.

 

[JP]

Cool....I'm going to put my VGs on in another ten hours or so. Just want to make sure I get the feel of it without the VGs first. Stall speed is pretty low as it is.

 

[centmont]

JP:
I'm in the middle of flight training, full of books but less than 40 hours at the stick. Nonetheless, If I "turn the nose into the wind" with the rudder, assuming cross wind, won't I have to counteract with left aileron to track straight? Wouldn't this lift the right wing and expose it to the crosswind? Forgive me if the answer should be obvious. I'm so excited about flying I frequently spend evening poring over this site and thinking about the answers....just couldn't make this one work out in my head. Thanks, Ralph

 

[JP]

JP:
I'm in the middle of flight training, full of books but less than 40 hours at the stick. Nonetheless, If I "turn the nose into the wind" with the rudder, assuming cross wind, won't I have to counteract with left aileron to track straight? Wouldn't this lift the right wing and expose it to the crosswind? Forgive me if the answer should be obvious. I'm so excited about flying I frequently spend evening poring over this site and thinking about the answers....just couldn't make this one work out in my head. Thanks, Ralph

Ralph, I got it wrong (I was thinking in reverse ref the slip and more along the lines of a simple wind drift crab on an aprproach). A good question--remember, I'm using a slip to lose altitude prior to transitioning for the flare phase. Yet, I also want it to be useful in counteracting the crosswind.

Imagine you are on final. You've got a crosswind from the right. You also have the runway made in case your engine quits, so you want to lose a little altitude. I give left rudder and right stick (cross control) for the slip.

So, my right wing goes down and I've got left rudder to stop the turn/adverse yaw.

If the crosswind is from the left, I go left wing down (left stick) and right rudder (cross control).

Slipping to the left feels really natural. Slipping to the right side still feels funny. So I practice that one more.

For a slip I suppose one could remember what to do by saying the following--from where the darn wind doth blow, keep that wing low!

Once I'm down and ready to flare I transition out by using the rudder to go straight down the runway and keep the low wing low to keep from drifting.

 

[Tailwheel Ted]

JP:
I'm in the middle of flight training, full of books but less than 40 hours at the stick. Nonetheless, If I "turn the nose into the wind" with the rudder, assuming cross wind, won't I have to counteract with left aileron to track straight? Thanks, Ralph

Ralph,

Think about it a moment. How do you turn a plane in the air? With bank. How do you bank? With ailerons.

So, the answer to your question is to bank into the wind with the ailerons just enough to keep you centered over the runway and then apply enough opposite rudder to keep it pointed down the runway.

Ted

 

[agavmechanic]

My cub doesn't have flaps, and I love slipping. It looks so cool too! As far as getting with an instructor and doing slips, it depends on the flight instructor. Most have flown nothing but Cessna's. And therefore are afraid to slip very much. -At least the instructors I've ran into. Need to get an older more experienced instructor if the one you have seems to be afraid to slip w/ or w/o flaps. Also, on my commercial checkride, I had the examiner pull power on me in a 182rg, and the gear circuit breaker. I had a thousand feet above the strip, about 1/2 mile away. I dropped one notch of flaps, started a 360 turn(in a glide) pumped the gear down manually, and when I finally got back on heading, I was still way high. I quickly explained to the examiner that I had a cub with no flaps and dropped two more notches in the 182, and a hard slip. I got it on the runway. It touched down about halfway down, but I got her done. It's all about how aggressive you need to be. I never did get the power back. He made me land the thing. Which was cool! Stressful, but cool!

 

[Tim]

JP, you should of been a lawyer, you have a way with words

 

[JP]

JP, you should of been a lawyer, you have a way with words

Tim:

Funny, I'm not a lawyer but I used to play one on tv....

JP

 

[JimC]

Ralph wrote:
>Nonetheless, If I "turn the nose into the wind" with the rudder, assuming >cross wind, won't I have to counteract with left aileron to track straight? >Wouldn't this lift the right wing and expose it to the crosswind?

Ralph, you'd turn the nose "away" from the wind (not into it) with the rudder while giving aileron toward the wind. The windward wing will be the low one. It might be easier to visualize the slip as just lowering the wing toward the wind and then using opposite rudder as required to keep from turning into the wind.

That said, the slipping technique that I usually use is full rudder and turn (or not) as desired by adjusting the ailerons.

Since the cabin is quite breezy if you do a right slip with the door open, I will usually left slip even with a crosswind from the right, as long as the crosswind isn't too severe, just cocking the nose more to the right to compensate (thereby coming down more sideways). The plane is relating to the air, not the ground, so raising the windward wing doesn't 'expose' it to a crosswind. That effect doesn't come into play till you have a wheel in contact with the ground.

JimC

 

[JP]

Ok, now that we're all on the same page (or wing, literally and figuratively)....

I find it natural and easy to slip left wing low. Second nature. Right wing low, well, it still feels funny. I've started practicing as much as I can on that side so that it will become second nature. To my delight I've discovered that it seems to slip fine in that direction, too. :lol: Breezy, though.

I'm fortunate inasamuch as my summer base has grass/gravel "runways" parallel to those strange paved things. Not sure what they are so I stay away from them.

 

[sj]

I frequently go base to slip instead of base to final. Most of my DW-Base-Final pattern is an arc anyway, so when coming around to final I leave the bank in and apply a bunch of opposite rudder to start the slip. I have found this is also more comfortable for the passenger since they are already banking. With the cub flaps, slips are mostly used in our part of the country to recover from poor planning, in the old non-flapper tango cub, they are a lot more useful and always fun in both.

If you are really going to operate on the edge, I would sugguest you go out with an instructor first and do some stalls, etc in slips.

I also agree with Bill's definition of a full slip: Full rudder and then appropriate aileron however, I have flown a couple cubs (mostly experimental) and other airplanes that there was not enough aileron to keep up with full rudder and had to back it off a tad.

Being extremeley confident to use a slip all the way to the ground is especially priceless in an engine out situation where you want to keep your options open until the last minute. Any slip training you do will pay off big time if this ever happens to you.

Just my thoughts.

sj

 

[labdad32]

Slips

I have not seen discussion relative to the nose attitude during slips. I was taught to keep the nose low, but have a friend that touts a slightly nose high attitude. Thoughts?

I was out slipping the Beaver on wheels the other day, using take-off flaps, and it comes out of the sky pretty fast but feels rock solid.

 

[JP]

Good question...

I've been taught that you can get the nose up quite a way before you get in the oh oh zone. Certainly level to 10 degrees up isn't a prob.

When I flew the J-3 a lot I slipped all the landings. You could really drop it on a spot that way.

My currrent task is getting used to the VGs on landing. I still float and/or flare too high on occasion. Gotta re-learn how to slow her down and drop it on from 2-3 feet. The -11 is a lot slipperier than the J-3.

 

[JimC]

>The -11 is a lot slipperier than the J-3.<

Hey, JP.
I got both a -3 and an -11, and you sure got that right. I tend to prefer the way the -3 responds to control input. Have you noticed a difference in the 'feel' of the two?
All the best,
JimC

 

[JimC]

>I have not seen discussion relative to the nose attitude during slips. I was taught to keep the nose low, but have a friend that touts a slightly nose high attitude. Thoughts? <

When slipping, I just use the nose attitude to control the airspeed and don't worry about whether the nose is high or low. If I want to speed up, I drop the nose a bit, and if I am getting too fast, I raise it. Consequently, I'm continually working the elevators just like the rudder and ailerons as I descend. Don't know if this is the correct way to do it, but it seems to work for me. My biggest problem seems to be coordination of rolling out of the slip at just the appropriate moment during the flare, so that I'm not drifting at touchdown and also have not killed the high drag configuration too far above the ground. I have trouble compensating for this with throttle because the C-85 engine stumbles and hesitates if I give it throttle too quickly. If I'm trying to be really slow, wait too late, and then get a quartering gust that kills even more airspeed as I'm rolling out of the slip and flaring, I sometimes make a less than perfect landing.
But heck, that's no surprise; as even the best of my landings are considerably less than perfect.
JimC

 

[Aviator]

...I find it natural and easy to slip left wing low. Second nature. Right wing low, well, it still feels funny...

Too much time in side-by-side cockpits, JP.

 

[JP]

>The -11 is a lot slipperier than the J-3.<

Hey, JP.
I got both a -3 and an -11, and you sure got that right. I tend to prefer the way the -3 responds to control input. Have you noticed a difference in the 'feel' of the two?
All the best,
JimC

The -3 feels "purer", more gentle and natural to fly. It is a subtle difference depending on what regimen of flight you are in. The -11 at lower rpm is very close to the -3 in flight. With the extra horsepower applied and the presence of the pressure cowl, she's a whole different animal on takeoff and landing.

The VGs improve roll controllability significantly in the -11, so it is a joy to dutch roll and honk around. Wind affects it far less than the -3, so you don't feel like you are flying a kite around on some days.

I really enjoy the front seat in the -11. Overall, my awareness is better and landings are really easy to do (just gotta slow down...). The view is tremendous.

They are both terrific "flying" airplanes. I bought the -11 so I could do more x-c trips. She settles in right around 90, which is a big difference from 62 mph in the 65 hp. J-3!! :lol: