Side-slipping
Not so N, but still FG
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Too much law? May we discuss a flying technique?
Air law has been somewhat prominent in recent discussions here and, of course, it's an important subject, but may we talk about some aspect of aircraft handling that has not been done over recently? I suggest that we overshoot away from landings, but what about something like side-slipping? How many people are or are not taught how to do it? How many people regard it as part of their everyday skill set? If possible, can we avoid concentrating exclusively on the wisdom or unwisdom of slipping in C172s with the flaps down, although by all means go on about that if it gets your cookies. What else? Lowering flaps in the final turn? Fireproof shreddies? Cup holders?
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Learnt forward and side slipping when flying gliders ... second nature now.
C172 ... I've slipped it OK with full flap but like you I don't really want to go there as the subject has been done to death!
SS
C172 ... I've slipped it OK with full flap but like you I don't really want to go there as the subject has been done to death!
SS
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It was only when I expressly asked for some extra crosswind landing instruction, post PPL, that I was taught anything about side-slipping and some uses for it.
Since having that training, I'm convinced that confidence has improved more rapidly since it gives and extra technique for use in various circumstances. I.e. a backup on occasion.
In the light of this, I'd have thought s/s should form part of the PPL syllabus.
Since having that training, I'm convinced that confidence has improved more rapidly since it gives and extra technique for use in various circumstances. I.e. a backup on occasion.
In the light of this, I'd have thought s/s should form part of the PPL syllabus.
Why do it if it's not fun?
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Ooh, side-slipping - Fun! Depending on the aircraft, of course.
I got my PPL on a PA28, and my instructor taught me to side-slip. Have never had any problems, and it can be a very useful technique.
Then I switched to a PA18, and one of my instructors taught my to side-slip properly (doesn't count unless you are using full rudder.... and preferably whilst turning in the opposite direction to that in which you've applied the rudder). Had a go at doing the same in a PA28 once, and it wasn't quite so comfortable as the PA18.
Then had a chance to fly a couple of aircraft like the Great Lakes, Pitts S2B and Tiger Moth where knowing how to side-slip is not just useful (and fun) but pretty much essential.
My Europa is not a nice aircraft to side-slip - it likes to pick up speed, and will very quickly go above Vfe with the flaps down unless you keep an eye on it. I try to practice regularly, but it's not something to do close to the ground unless you're in practice.
And finally there's the C172 - the ones I fly warn against side-slipping with full flaps in the POH, so I've never tried it.
The moral of the story? From my limited experience, it seems to depend very much on the type of aircraft you fly. Some can't do it, some can but only if you're careful or only up to a certain point. Others are brilliant at side-slipping. Definitely something that you should get someone to show you if you fly a suitable aircraft, though, IMHO.
FFF
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I got my PPL on a PA28, and my instructor taught me to side-slip. Have never had any problems, and it can be a very useful technique.
Then I switched to a PA18, and one of my instructors taught my to side-slip properly (doesn't count unless you are using full rudder.... and preferably whilst turning in the opposite direction to that in which you've applied the rudder). Had a go at doing the same in a PA28 once, and it wasn't quite so comfortable as the PA18.
Then had a chance to fly a couple of aircraft like the Great Lakes, Pitts S2B and Tiger Moth where knowing how to side-slip is not just useful (and fun) but pretty much essential.
My Europa is not a nice aircraft to side-slip - it likes to pick up speed, and will very quickly go above Vfe with the flaps down unless you keep an eye on it. I try to practice regularly, but it's not something to do close to the ground unless you're in practice.
And finally there's the C172 - the ones I fly warn against side-slipping with full flaps in the POH, so I've never tried it.
The moral of the story? From my limited experience, it seems to depend very much on the type of aircraft you fly. Some can't do it, some can but only if you're careful or only up to a certain point. Others are brilliant at side-slipping. Definitely something that you should get someone to show you if you fly a suitable aircraft, though, IMHO.
FFF
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I've never sideslipped a 172 either.
But it strikes me that there are two possible reasons for such a prohibition. One is that it creates a handling problem, most likely longitudinal or directional instability (I saw both on a prototype once when sideslipping with full flaps, quite exciting). The other is that there is a combined rudder / aileron / flap (probably the last two) stress case which is considered hazardous to the airframe and therefore was prohibited.
Now if shortstripper has found no handling problem in sideslipping a 172....
G
But it strikes me that there are two possible reasons for such a prohibition. One is that it creates a handling problem, most likely longitudinal or directional instability (I saw both on a prototype once when sideslipping with full flaps, quite exciting). The other is that there is a combined rudder / aileron / flap (probably the last two) stress case which is considered hazardous to the airframe and therefore was prohibited.
Now if shortstripper has found no handling problem in sideslipping a 172....
G
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I was taught to do it properly during taildragger difference training on an aircraft without flaps, so again it was pretty much essential. Until then it had not really been taught very well, i.e. I hadn't learned to do it. 
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I fly a Rallye 100 into 320 M of grass, over trees from one end. In zero wind I "MUST" side-slip to get down in order to leave a reasonable margin to stop.
It goes back to the thread on "real pilots", For some reason young instructors in the main don't teach side-slipping, many new PPLs don't know about it nor when to use it.
If you must come in "high" over trees etc, or you "end up" too high on approach, you want to loose as much height as possible while travelling the least forward distance.
Therefore if you are still high while flying at minimum approach speed then you must "make" the aircraft fly less efficiently to increase the rate of "sink", side-slipping is the safest way to do this.
The C172 with 40 degree flaps should not be sideslipped with "full" flap. This is not because the aircraft will fall apart, but because the vertical fin could stall due to the disturbed airflow over the fin and rudder at a slow speed. As you already may have input full aileron, the aircraft could roll unexpectedly and perhaps through 90 degrees before you are able to recover. (not something you would want to happen close to the ground).
To side-slip without full flap in a 172 with 40 degree flap, will not give you any advantage over just using full flap and keep the speed at min approach speed.
Go out and learn to fly cross controls, find a good old "cub" pilot to go with you.
Tony
It goes back to the thread on "real pilots", For some reason young instructors in the main don't teach side-slipping, many new PPLs don't know about it nor when to use it.
If you must come in "high" over trees etc, or you "end up" too high on approach, you want to loose as much height as possible while travelling the least forward distance.
Therefore if you are still high while flying at minimum approach speed then you must "make" the aircraft fly less efficiently to increase the rate of "sink", side-slipping is the safest way to do this.
The C172 with 40 degree flaps should not be sideslipped with "full" flap. This is not because the aircraft will fall apart, but because the vertical fin could stall due to the disturbed airflow over the fin and rudder at a slow speed. As you already may have input full aileron, the aircraft could roll unexpectedly and perhaps through 90 degrees before you are able to recover. (not something you would want to happen close to the ground).
To side-slip without full flap in a 172 with 40 degree flap, will not give you any advantage over just using full flap and keep the speed at min approach speed.
Go out and learn to fly cross controls, find a good old "cub" pilot to go with you.
Tony
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PPL syllabus, by Tony R
20 hours in a can, 172 or PA28
5 hours in a Glider
5 hours in a Cub
2 hours Aeros ( Cap10 or something similar)
5 hours instrument (at least one ILS to 500 feet FOR REAL)
2 Hours in something fast and complex
1 flight in a multi engine
1 or more parachute jump to finish
After which you can go and learn to find your way around.
Tony
20 hours in a can, 172 or PA28
5 hours in a Glider
5 hours in a Cub
2 hours Aeros ( Cap10 or something similar)
5 hours instrument (at least one ILS to 500 feet FOR REAL)
2 Hours in something fast and complex
1 flight in a multi engine
1 or more parachute jump to finish
After which you can go and learn to find your way around.
Tony
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I was always told that you NEVER side-slip with flaps down... especially not full flaps. I can't find anything about it in all the flying books I own, but it seems sensible to me.
Westy
P.S. side-slipping a PA18 is sooo much fun!!
Westy
P.S. side-slipping a PA18 is sooo much fun!!
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Most aircraft are Ok to slip with full flap. and in most aircraft if you don't use full flap your side-slip will make little difference to your approach, so why bother.
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Re the flaps and as per my ATPL course: When side-slipping, if flaps are deployed then the mean lift point moves in board towards the root. This reduces the stabilsing leverage and makes the aircraft unstable. Propeller wash has a similar effect. Apparently, low-wing aircraft are also generally unstable in the side-slip. High wing and swept wing aircraft are the most stable. If you draw a picture it is instantly possible to see the AoA differences and imagine how the airflows overthe fuselage and onto the wings. Intersting stuff.
However, I don't have the courage to try side-slipping for real without being taught. Where can I go in the Surrey/Hampshire area to learn how to do these kind of things?
However, I don't have the courage to try side-slipping for real without being taught. Where can I go in the Surrey/Hampshire area to learn how to do these kind of things?
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I would suggest taking any type of light single you fly, take it high, preferably with an instructor or experienced safety pilot, and glide down, slipping it even as far as full rudder deflection in each direction. Note to avoid spinning and killing yourself - KEEP THE SPEED UP, and treat the ASI with caution (it may under-read).
Tried this recently with a high-hour "student" (was retraining from lots of experience stateside - I learnt there under a very good instructor, why can't they all teach what he taught me? Why is there so much bad training of Europeans out there, when much of the FAA training is quite good?) who really had never been shown the sideslip. Very useful exercise, especially in a Robin 200 (tiny flaps, maximum 20 degrees).
High-wing - if you can get to the other side of Hampshire I'd be delighted to show you.
TonyR
I could show you what can be done by way of angle of descent with sideslip but little flap.
Tried this recently with a high-hour "student" (was retraining from lots of experience stateside - I learnt there under a very good instructor, why can't they all teach what he taught me? Why is there so much bad training of Europeans out there, when much of the FAA training is quite good?) who really had never been shown the sideslip. Very useful exercise, especially in a Robin 200 (tiny flaps, maximum 20 degrees).
High-wing - if you can get to the other side of Hampshire I'd be delighted to show you.
TonyR
I could show you what can be done by way of angle of descent with sideslip but little flap.
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I've never asked Mr Cessna why side slipping with full flaps on the 172s I've flown is prohibited, but it certainly is not allowed in the POH.
There is a view amongst some jocks with much more experience than me that the 172 can stall with a very big wing drop and enter into a spin when slipping with full flaps if the airspeed is allowed to decay , but as I say, I've always followed the rules.
Having slipped PA28s extensively, its a great way to lose height rapidly and anyone who hasn't learned it would do well to spend some time with an instructor - the best thing is as soon as you remove the cross controls, the aircraft flies completely normally again, not pitch up or down as experienced when latering the flap settings in some aircraft.
There is a view amongst some jocks with much more experience than me that the 172 can stall with a very big wing drop and enter into a spin when slipping with full flaps if the airspeed is allowed to decay , but as I say, I've always followed the rules.
Having slipped PA28s extensively, its a great way to lose height rapidly and anyone who hasn't learned it would do well to spend some time with an instructor - the best thing is as soon as you remove the cross controls, the aircraft flies completely normally again, not pitch up or down as experienced when latering the flap settings in some aircraft.
That's interesting, as I was taught side slipping at the same place that DJRAD wasn't. It was shown to me in more than one lesson, infact I remember coming in a bit high on a dual circuit once or twice during lessons, so sideways we went
I also remember one of the comments which was said in jest, "OOOoooooo flash ba5tard"
The thing that I should practice more is getting out of it without coming off the centre line of the runway, as I tend to find that I always let off either more foot than stick and go all over the place.
Something like that anyway.
I also remember one of the comments which was said in jest, "OOOoooooo flash ba5tard"
The thing that I should practice more is getting out of it without coming off the centre line of the runway, as I tend to find that I always let off either more foot than stick and go all over the place.
Something like that anyway.
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HWD. You know where you can come to in surrey to be tought!
As for the cessna slip with full flap:-
1 )Think about the relative airflow in that condition
2) Think about what will happen to the airflow that passes over (and under) the wing (Into the slip)
3) Think about which control surfaces will be masked by aforementioned wing & flap
4) You have your answer!
Send Clowns. The ASI may Under or Over read depending on the direction of slip (Assuming only one static vent).
As mentioned by a pevious poster. The sideslip is part of the JAA syllabus (as it always was with the CAA syllabus).
As for the cessna slip with full flap:-
1 )Think about the relative airflow in that condition
2) Think about what will happen to the airflow that passes over (and under) the wing (Into the slip)
3) Think about which control surfaces will be masked by aforementioned wing & flap
4) You have your answer!
Send Clowns. The ASI may Under or Over read depending on the direction of slip (Assuming only one static vent).
As mentioned by a pevious poster. The sideslip is part of the JAA syllabus (as it always was with the CAA syllabus).
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I'd read about side slipping and already crabbed and attempted wing down landings (they just dont feel natural!)
I was doing an approach and my instructor said (quite rightly) you're obviously too high here, so do something about it.
A bootful of left rudder and a twist of the yoke adjusted the vertical hold nicely (2 reds 2 whites). Controls to centre brought us back onto a normal descent. I think it took my instructor by surprise.
Pity I forgot to do it at Gloucestershire on my QXC as I sailed over the runway at about 500ft with full flap, throttle off and me bashing the dash with a kneepad shouting 'Down Boy !! Land dammit'. After go around I stopped short of the gravel trap (marked satisfactory) .
Must try it on a PA 28 next time I'm looking down at the threshold from on high.
I reckon it's better than just winding on the flap and wishing you had spoilers.
I was doing an approach and my instructor said (quite rightly) you're obviously too high here, so do something about it.
A bootful of left rudder and a twist of the yoke adjusted the vertical hold nicely (2 reds 2 whites). Controls to centre brought us back onto a normal descent. I think it took my instructor by surprise.
Pity I forgot to do it at Gloucestershire on my QXC as I sailed over the runway at about 500ft with full flap, throttle off and me bashing the dash with a kneepad shouting 'Down Boy !! Land dammit'. After go around I stopped short of the gravel trap (marked satisfactory) .
Must try it on a PA 28 next time I'm looking down at the threshold from on high.
I reckon it's better than just winding on the flap and wishing you had spoilers.