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The big slip

cgoldy

Registered User
Moogerah Queensland Australia
I am not a numbers man and fly by feel. I fly slow and low 90% of the time and just love it. But sometimes I wonder about my slips. I am comfortable slipping all the way to the flare, full rudder and appropriate aileron. I have been slipping like this for 15 years. But I don’t understand what the ASI is telling me. If I am flying at 30 knots, 5 knts above my stall, and radically slip, I often see 45 on the AIS but I don’t think I have altered the stick position. I would think in a slip the pitot would be traveling sideways to the airflow and showing a lower IAS. The plane always feels solid and safe in a radical slip. Am I close to something I have not experienced before? Am I subconsciously adding forward stick? Does stick position in relation to stall still apply in a slip? Please no smart arse comments about safe flying.

cgoldy
 
why dont you just experiment a little? I find this works the best, climb up to an altitude you would be happy to enter a spin from (usually 2000ft AGL is good for me) set an imaginary altitude as "ground" and try a couple of slips with the stick in different positions. not saying you will enter a spin but I am rather happier to be higher than lower
 
Have you tried with a slip to the other side. Just as a test. Reasoning, I would be curious if the fuselage is blanking the spanwise flow and building pressure in the region of the pitot which in a slip to the other side would result in a reduction of pressure in the pitot region.
Good chance this has no effect as well and is a broken theory.
 
I think by going into the slip you have lost some lift so you will increase you downward and vertical speed at the same time, so you are going to have to pick up the nose more to keep the same forward airspeed. The smart guys should correct me if I am wrong. Just go off the gps speed. I would recommend everyone have spin training before attempting what I am going to recommend. I prefer 4,000 ft AGL when I do my hard slip training. In my cub I can do a hard slip and keep pulling back until the upper wing drops, when it does just let the nose down and as the plane comes level move into a slip in the opposite direction much like a exaggerated falling leaf maneuver. Repeat as needed. This keeps you close to the center line on approach. This will also give you a feel for how your plane reacts to a stall during a slip. I was shown this maneuver in a Pacer by my first instructor (old crop-duster) I only had many 40 hours at the time and did not fully understand what was happening but in his hands it was magic. 1400 hours latter and I kind of make it work but not like him. Due to the angles and dangles involved it feels different than a normal slow flight attitude and takes some getting used to. DENNY
 
I was going to say something similar to what Denny and bodumatau said. When I first learned of slips, I was thinking, "how is this going to be different from a spin or snap roll?" I had an instructor who wanted me to learn spins, so we added slips as an entry point to see what happens.

It became clear that if you were in a normal slip, you had to work pretty hard to get the upper wing to stall. When it got close, it seemed pretty obvious, at least to me.

I did all this in Tomahawks and Citabrias, and later in a Cessna 172. I think playing with it up high is a really good thing to do.
 
I should try this in a Super Cub with full flaps. In a J3 you can enter a full rudder slip, then slowly pull the stick full aft. It will not stall. I really didn't believe it until I tried it.

I admire the caution of folks who go to 4000' agl for spin training. If you get into a spin in a Cub that costs you a thousand feet, you really need to study recovery techniques. That is, unless you want multiple turn spins.

When I teach spins, the recovery starts right after the spin has developed - usuallly a half to 3/4 turn. The hardest part is getting a clean entry.
 
When I did my spin training in a Great Lakes Biplane we tried to enter a spin from the slip the top wing would fall level then go back into a slip if you just held the controls in the same spot. Rick Stowell noted in his book a forward slip is about as safe as you can get. DENNY
 
I was thinking about this all morning. The most extreme "forward slip" would be a knife-edge maneuver. At that point, the wings provide no lift. The fuselage is the lifting body.

So, as you go from straight and level toward knife edge, wing loading drops and the fuselage takes on more lift. Maybe that's why it is hard to stall the upper wing in a full slip.
 
I recall doing extended slips and skids in four Cubs - w or w/o flaps - w or w/o extended wings. I came away believing slips to stall could be managed with available control; skids to stall were more often followed by upset into a pre-spin and were to be avoided.

Gary
 
Colin, Your ASI is telling you to look out the window and stop looking at the instruments. 8) Do you have static ports on your pitot tube? Slipping sideways likely creates a sucking action on the static ports causing an increased speed reading. Sucking on static ports does the same thing as blowing in the pitot.
Slip it as radically as you feel comfortable. As long as you get a reverse action from the controls when you move them you are not too slow. Unless you've done something to the plane which creates an abrupt quick stall or loss of control, you should be safe standing it on a wing tip with the nose pointing at the sky in a slip. Yes, this is an extreme. As long as you get an instant tendency to recover when you relax the controls you are safe. Just pay attention to rate of sink close to the ground allowing enough altitude to stop the sink rate. You will know if it is going to do an upset of some sort.

Flying on the edge is safe as long as you know where the edge is.
 
Colin, Your ASI is telling you to look out the window and stop looking at the instruments. 8) Do you have static ports on your pitot tube? Slipping sideways likely creates a sucking action on the static ports causing an increased speed reading. Sucking on static ports does the same thing as blowing in the pitot.
Slip it as radically as you feel comfortable. As long as you get a reverse action from the controls when you move them you are not too slow. Unless you've done something to the plane which creates an abrupt quick stall or loss of control, you should be safe standing it on a wing tip with the nose pointing at the sky in a slip. Yes, this is an extreme. As long as you get an instant tendency to recover when you relax the controls you are safe. Just pay attention to rate of sink close to the ground allowing enough altitude to stop the sink rate. You will know if it is going to do an upset of some sort.

Flying on the edge is safe as long as you know where the edge is.


Thanks guys, you have given me confidence to go high and explore the slip envelope. Pete, I think you have nailed it again. The static is on the pitot.
 
Better be ready for the spin entry from a slip! Its not the same as a skidding entry. Lowel level it usualy ends up with the plane in a smoking hole. Most people who use their planes on the job for low level work (especialy slow menuevering) avoid flying the airplane uncoordinated. I know this thread was about airspeed indications, but impressionable minds are reading this. Me personaly, i fly a no flap pa11 and i can count on one hand not using all five fingers how many times ive slipped it over the years. Just my two cents.
 
Me personaly, i fly a no flap pa11 and i can count on one hand not using all five fingers how many times ive slipped it over the years. Just my two cents.

Guess I must be a special kind of dumb then because I slip to nearly every landing. If you wanna get over an obstacle and on the ground in a no-flap cub you just have to master the slip. Like skywagon8a said, you can fly on the edge safely as long as you know where that edge is.

Nothing wrong with slipping to landing IMO. I manage airspeed with pitch and just go in and out of a slight forward slip to manage approach angle. I could use throttle but I normally use a high approach so I'm already at idle so gotta bring some slip in to get out of the air and hit my spot. It's also a case of what may be safe in a cub may not be safe in another aircraft that has a more violent stall/spin characteristic. The cub is definitely more forgiving of getting slow and uncoordinated.
 
It's getting kind of stale in here middle of the winter. Let's get a good old lively debate going!:wink:
 
Get a qualified instructor and go for a ride in your plane as it's currently rigged. Find out what it does coordinated and with skids-slips. Convince yourself to pay attention.

Gary
 
I echo the practice suggestions! But I’ve found if you maintain your pitch in the slip you typically don’t change your airspeed. Most folks tend to lower the nose thinking they’re going to stall, increasing airspeed and thus float. YMMV
 
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Better be ready for the spin entry from a slip! Its not the same as a skidding entry. Lowel level it usualy ends up with the plane in a smoking hole. Most people who use their planes on the job for low level work (especialy slow menuevering) avoid flying the airplane uncoordinated. I know this thread was about airspeed indications, but impressionable minds are reading this. Me personaly, i fly a no flap pa11 and i can count on one hand not using all five fingers how many times ive slipped it over the years. Just my two cents.

Nope

Glenn
 
I'm like Crash Jr I slip to most landings. What will really get your attention when in a really hard slip is to have the window blow into the plane there is a Huge pucker factor for a couple of seconds.
 
I'm like Crash Jr I slip to most landings. What will really get your attention when in a really hard slip is to have the window blow into the plane there is a Huge pucker factor for a couple of seconds.

Flew Cubs for so long with the door open (and had that happen a couple time) I only slip to the left out of habit now. I’m also in the camp of slipping on most landings with a Cub. Once my Clipper is together, that will also be slips to almost every landing as well.


Sent from my iPad using Tapatalk
 
Doors open or off I've never lost any windows in a Cub, J4, Champ or anything else. In a Stearman or most biplanes the only way your going to find the runway or anything else is to slip it till the wing almost almost drags.
 
Get a qualified instructor and go for a ride in your plane as it's currently rigged. Find out what it does coordinated and with skids-slips. Convince yourself to pay attention.

Gary


but be aware that the plane (cub) will behave a bit differently with a guy in the back.
I took a long time GA pilot up once as px who thought we were nuts for flying so slow.
At 4000’ got slow and went thru a series of maneuvers, deep into spin territory, bragging all the while at how docile a cub was, he was slowly being converted when, wham! The wing came over so hard we pendulumed upside down for a moment.
I have since never been able to duplicate that maneuver while flying alone.

His wife won’t let us hang out together anymore.
 
Best fun maneuver in a Flight Review is a turning Slip power off from downwind to spot landing. Done right it's land on a dime and get 5 cents change.

Gary

This right here.
I spent a few days doing this a couple years ago and when you hit it perfect it was awesome. Constant slip in a constant radius from downwind to touchdown. I had to go back and look at my track logs just to smile about it.


Transmitted from my FlightPhone on fingers...
 
I'd be curious if those in the camp of "slips are dangerous" still do side slips in a crosswind. It's still an uncoordinated maneuver folks!
 
I know more than one ATP pilot that has told me slips are dangerous (they crab and kick in crosswind) How many times have you read that you should ALWAYS keep the ball centered. Ya everyone is taught about a skip/skid turn in when you start but it was just on 5 min point combined with 20 other things then move on. If you don't fly small planes/taildraggers it is easy to miss/loose that bit of information. I think I spent two years asking pilots about the safety of slips and every time I got a different answer. After my Spin/Aerobatic training I had a better feel for it. Reading Ricks book I was able to better understand why(go figure training + reading = knowledge]. Understanding the difference between a slip and a skid is very important but I feel sometimes the shortcut answer to students is always keep the ball centered. DENNY
 
Passenger comfort often dictates how the plane is flown. Get them queasy and it's sometimes followed by a safety meeting or whack on the head.

Gary
 
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