Learning Forward Slip Landings

Fellow_Pilot

Fellow_Pilot

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Fellow_Pilot
I’ve been working on forward slip landings for a little bit and can’t seem to get the plane to consistently/reliably land within 400 feet past aiming point (beginning of first stripe). Most of the time, I would end up floating past my point past 400 feet. I know practice makes perfect and all, but is there some kind of technique that one could possibly use to more reliably touch down within 400 feet per the ACS? Thanks!
 
Are you flying the proper airspeed? When are you closing the throttle? Is your aiming point an appropriate distance ahead of your touchdown target?

Could be lots of things, but it’s hard to tell from here. ;)
 
MauleSkinner said:
Are you flying the proper airspeed? When are you closing the throttle? Is your aiming point an appropriate distance ahead of your touchdown target?

Could be lots of things, but it’s hard to tell from here. ;)
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I try to aim at my approach speed and usually close the throttle on final. I usually aim for roughly the threshold of the runway.
 
Fellow_Pilot said:
I try to aim at my approach speed and usually close the throttle on final. I usually aim for roughly the threshold of the runway.
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“Try”, “usually”, and “roughly” are probably your problem. If you’re not consistent in your technique, you can’t make appropriate corrections.
 
MauleSkinner said:
“Try”, “usually”, and “roughly” are probably your problem. If you’re not consistent in your technique, you can’t make appropriate corrections.
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True, I’ll give that a shot.
 
Are you flying an approach speed off a checklist, or 1.3*Vso for your weight?
 
I’d also suggest that maybe your touchdown target is too close to the threshold.
 
Keep in mind that your ASI will read erroneously while you’re in the slip, so it’s possible that you’re flying faster than you realize. You might also consider beginning the slip a bit earlier in the sequence to ensure that you’re losing enough altitude to make your intended touchdown point.
 
Ryanb said:
Keep in mind that your ASI will read erroneously while you’re in the slip, so it’s possible that you’re flying faster than you realize. You might also consider beginning the slip a bit earlier in the sequence to ensure that you’re losing enough altitude to make your intended touchdown point.
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How would you correct for the misinformation of the ASI?
 
Are you "practicing" a forward slip or find that you "need" a forward slip to spot land? Have you tried holding the slip a little longer such as a second or two?
 
Timbeck2 said:
Are you "practicing" a forward slip or find that you "need" a forward slip to spot land? Have you tried holding the slip a little longer such as a second or two?
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It’s for the checkride.
 
Fellow_Pilot said:
How would you correct for the misinformation of the ASI?
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Really just continued practice and knowing how the attitude of the nose effects the descent rate and airspeed.

Are you slipping in the landing configuration?
 
I guess my other question would be, what are you thinking the slip is supposed to be doing, and/or how long you’re supposed to hold the slip?
 
Fellow_Pilot said:
I’ve been working on forward slip landings for a little bit and can’t seem to get the plane to consistently/reliably land within 400 feet past aiming point (beginning of first stripe). Most of the time, I would end up floating past my point past 400 feet. I know practice makes perfect and all, but is there some kind of technique that one could possibly use to more reliably touch down within 400 feet per the ACS? Thanks!
Click to expand...

When you miss it are you always long? Or do you come up short sometimes? Lots of techniques mentioned above, all good as far as I see it. Repetition. As far as the correcting for airspeed goes you need to find out how much off its going to be first, then add or subtract as necessary. What airplane do you fly?
 
Fellow_Pilot said:
How would you correct for the misinformation of the ASI?
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You can look at the ASI after you kick it straight - the indicated speed is likely to go up - that could be why you float, then you know to slip with the nose higher next time.
 
Let’s explain a forward slip a little differently. You are basically using the rudder as a flap that produces drag without adding lift.

As you reduce the power to idle and apply the the aileron and rudder, you decrease the pitch attitude as you would by dropping flaps. You use bank for directional control, and pitch for airspeed. When you decide to end the maneuver, roll wing level as you increase the pitch and slowly let the flap out to control airspeed. If you roll out and let the rudder out, you get an airspeed increase and land long.
 
Fellow_Pilot said:
How would you correct for the misinformation of the ASI?
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This may have been addressed earlier but relying on IAS will mess you up on some/many aircraft.

The key in my experience is angle of attack, but I’m not talking about an instrument. Pick a proper IAS while in coordinated flight on final. Take a mental picture of your AOA based on the nose and the ‘horizon’. Then go into your slip while keeping the AOA constant based on the nose and the ‘horizon’ (forget the ASI).

You may think that with the nose yawed one way and the wings banked in another that any reference between the nose and what I’d call the apparent horizon, would be screwy. It’s not. Try it and you’ll see. Set your approach configuration and trim that gives you your target IAS. Take a mental picture and them enter your slip. You will immediately find a bit of back pressure is required to maintain the AOA picture. That’s normal in every one of the few aircraft I’ve flown. Check the ASI but don’t fly it. Once you know how it acts, it’s a good cross check for that aircraft.

Do that and you enter a slip that will increase your descent angle and rate to the touch down point. It will be in in front of where you would have landed without the slip if you don’t increase power.

I don’t trim out the extra back pressure. If I come out of the slip early. I’m perfectly trimmed. If I hold it to round out, I just keep the back pressure on as I come out of the slip increasing to whatever is required for landing.

This is useless info for pilots of planes that don’t slip well, which means planes where the rate and angle of descent doesn’t increase significantly in a slip.

This is a key to the castle for someone learning to land something like a Schweitzer 2-22 glider. Gliders are close to impossible to land without spoilers or flaps. The 2-22 has very ineffective spoilers. Therefore a slip is part of all normal landings. And theirs no engine to confuse things.

Rent a Cessna 15x 17x and figure it out.








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Clip4 said:
Let’s explain a forward slip a little differently. You are basically using the rudder as a flap that produces drag without adding lift.

When you decide to end the maneuver, roll wing level as you increase the pitch and slowly let the flap out to control airspeed. If you roll out and let the rudder out, you get an airspeed increase and land long.
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Sorry but this is terrible advice. What you're describing (unless I misunderstand) is removing the aileron before the rudder when coming out of the slip. This is a great way to kill yourself in some airplanes that have more effective controls than most trainers do. Bad and potentially dangerous technique regardless. What happens is that you transition from a slip to a skid. Slips are quite spin resistant. Skids are not. You do not want to skid at low altitude. I have a friend who was killed slipping his Pitts on approach and spun in on short final. Only real way to do that is to remove the ailerons before you've removed the rudder. You should always remove the aileron and rudder simultaneously while coming out of a slip. The rudder has nothing to do with airspeed control during and coming out of a slip. It's all pitch attitude control.
 
In addition to the above, I’m confused about the pitch up statement. In the two planes I fly regularly, I pitch down when doing a forward slip. Otherwise you just slow down and descend at the same rate rather than descending faster at the same speed.

Never mind, I misread it. The pitch up statement was for exiting the slip.
 
This for PPL? On my PPL Checkride I got s thataboy from my DPE on my slip to landing.

Started my pattern 200’ high and once I turned final I slipped it all the way down holding my 80kt approach speed the entire way. Rolled out once over threshold into a perfect no flap landing.

My first CFI taught me slips as a quick 1-2 second adjustment and I never understood their purpose. My last instructor taught me them as a complete tool
 
Clip4 said:
Let’s explain a forward slip a little differently. You are basically using the rudder as a flap that produces drag without adding lift.
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??? The rudder is a very small control surface, and its contribution to increasing drag is minimal. By entering a slip you are turning the airplane partly sideways into the relative wind, dramatically increasing its effective frontal area. The more rudder authority you have, the more fuselage area you can put in the relative wind. The dramatic increase in drag of the whole airplane can cause spectacular rates of descent in a plane that slips well. It's a valuable maneuver if you are too high for an emergency landing, and very safe as long as you keep your airspeed appropriately up. 80 mph in a full rudder slip in an AA5 will come down in a hurry, with or without flaps. It's great maneuver for clearing tall trees just off the end of the runway when landing.
 
Jamie Kirk said:
Started my pattern 200’ high and once I turned final I slipped it all the way down holding my 80kt approach speed the entire way. Rolled out once over threshold into a perfect no flap landing.
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I think that’s beyond the intent/requirement of the ACS, so an attaboy would be appropriate.

The landing criteria in the ACS are the same as for a normal landing, so I’d take that to mean one can transition to a “normal” attitude prior to the flare. Although recovering from the slip just in time to ensure the tire touches down before the wingtip is fun. ;)
My first CFI taught me slips as a quick 1-2 second adjustment and I never understood their purpose. My last instructor taught me them as a complete tool
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The object, at least for purposes of the ACS, is an adjustment to get down to the normal glide path. If you only need a second or two of forward slip, there are other, better, ways to make that adjustment IMO.
 
Jamie Kirk said:
This for PPL? On my PPL Checkride I got s thataboy from my DPE on my slip to landing.

Started my pattern 200’ high and once I turned final I slipped it all the way down holding my 80kt approach speed the entire way. Rolled out once over threshold into a perfect no flap landing.

My first CFI taught me slips as a quick 1-2 second adjustment and I never understood their purpose. My last instructor taught me them as a complete tool
Click to expand...

Though I had soloed a 150 years earlier, I took my PPG flight test with a guy I didn’t know and in a plane I had maybe 2 flights in. For the simulated off field landing where you have land on a spot and stop short of another point, I setup the Schweitzer 2-33 just like the 2-22; high with some spoilers. Too high except for the fact my plan included a full rudder deflection slip to the flare. The 2-33 slips well but full spoilers are also very effective.

“...very unnecessary but well executed”


Sent from my iPhone using Tapatalk Pro
 
luvflyin said:
When you miss it are you always long? Or do you come up short sometimes? Lots of techniques mentioned above, all good as far as I see it. Repetition. As far as the correcting for airspeed goes you need to find out how much off its going to be first, then add or subtract as necessary. What airplane do you fly?
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I fly a Cessna 152
 
What I usually do is I stay at pattern altitude, extend my downing ever so slightly, as soon as I turn final, I lower my final notch of flaps, take out the power, and slip to the runway.
 
Bill Watson said:
Though I had soloed a 150 years earlier, I took my PPG flight test with a guy I didn’t know and in a plane I had maybe 2 flights in. For the simulated off field landing where you have land on a spot and stop short of another point, I setup the Schweitzer 2-33 just like the 2-22; high with some spoilers. Too high except for the fact my plan included a full rudder deflection slip to the flare. The 2-33 slips well but full spoilers are also very effective.

“...very unnecessary but well executed”


Sent from my iPhone using Tapatalk Pro
Click to expand...
We had a wind shift during my checkride, and I ended up landing downwind...slipped the crap out of the 2-22 with spoilers to get it down in time.:rolleyes:
 
Fellow_Pilot said:
Most of the time, I would end up floating past my point past 400 feet.
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It’s been said before, but it’s quite simple: if you’re floating excessively, it just means you’re entering ground effect with too much speed/energy. Your instructor should be able to pinpoint why that’s happening and what to do about it.

As an aside, I like to come in a bit high and use some slip on nearly every approach.
 
Fellow_Pilot said:
I fly a Cessna 152
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Ok. Static port is on the left side (I think, verify this). If you are doing a right rudder/left aileron slip, the static port is ‘into’ the wind. This increases the pressure on the static port which gives the same result as less pressure in the pitot tube. Airspeed will read low. You are actually flying faster than the ASI indicates. Left rudder/right aileron puts the static port behind the fuselage and there will be a little less pressure than usual. This will have the effect of the ASI reading higher. You are going slower than it reads. There may be some issues with the pitot tube being ‘shielded,’ it’s on the left side (verify this) but I don’t think that effect is as pronounced as the static port issue.

Take this as background info. What is said above about your ‘sight picture’ is more important. Anyway, there are a lot of CFI’s around here that I’m sure have spent a lot of time in a 152 and can maybe give you some accurate numbers.
 
I used to love to slip, aiming toward the threshold, always, and coming in crazy steep as you can do with a 172 cranked sideways. It's like "flaps 40" but you can undo it instantly. With practice, you can leave the straightening up until later and later. We usually tried to land very close to the threshold, as to make the reverse turnoff at our airport, to save two miles of taxiing.
 
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