Side slipping Cessna's

[MJR]

I Know I should know this already as I have flown a few hours in 152's and 150's. But can some one please tell me what the side slip limitations are on Cessna's. I've checked a POH/FM but it did not offer any advice.

[GJB]

Not entirely sure, but I believe that you shouls only side-slip with the airspeed in the green arc.

[mad_jock]

If you are doing a slip to land always do it wing up with the tank breather on it, otherwise the fuel pisses out everywhere. Then drips on your head when you next preflight it.

MJ

[OnTheStep]

as far as speeds go, i don't see a problem with slipping anywhere in the green or in the top of the white for that matter. bearing in mind your vfe limitations, the asi is reading lower than your actual airspeed anyways because of the reduced ram air. the fuel selector should be on both or the wing that is higher of the two so that the fuel port in the tanks does not become uncovered which is more of a problem in pipers (not that they slip very well anyways).

as for the advice to <font face="Verdana, Arial, Helvetica" size="2">always do it wing up with the tank breather on it</font> this might be an interesting proposition with a strong left xwnd on appr, i'd opt for wing down on the upwind side. jmho

[This message has been edited by OnTheStep (edited 18 June 2001).]

[This message has been edited by OnTheStep (edited 18 June 2001).]

[mad_jock]

Fair comment.

Unless good airmanship dictates otherwise.

:) Howes that ?

But if it was that bad i wouldn't be doing a slip to land anyway. It would be flaps up, crab, yaw, drop the wing then down so you wouldn't lose that much.

MJ

[OnTheStep]

personal preference i suppose, i'd be shooting for 10/20°, and side slipping short final to maintain centre line then *chirp, chirp, chirp* as the left/right/nose touched down. once you're stable in the slip on short final, the flare is considerable less busy as it becomes an issue of simply flaring and touching down with the xwnd inputs in already making the rollout a non event as well. i guess my partiality to this technique is a result of my gliding days.

[mad_jock]

It actually seems to be a bit of a debate which method to use.

If you do it your way you can run the risk of stalling one wing if you get hit by a gust.

An the other if you get hit and the plane stalls at least both wings go and you have a chance of recovering. Which i don't think you would have much luck with than a single wing stall on the appr.

But i agree with you there is rather alot going on during the flare but it all seems to work together for me now.

I believe the big boys use the crab method as well. Could any of the jet drivers help us out on this one ?

MJ

[OnTheStep]

to me it seems like apples and oranges to compare the flare and touchdown of a 172 to the roll on of a jet. i'm sure they're quite apt to touchdown with some sideways loading that to risk digging an engine into the concrete in a wing-low touchdown.

with the upwind wing low, there's less susceptability for said wing to be pickup up by a gust that could lead to a loss of directional ctrl....or if you're on floats- lead to an unplanned swim

[mad_jock]

I really don't know but all the schools i have been to have advised against it.

And i have been told if you do it during your CPL you will fail.

I tell you what seeing as we both arn't going to learn anything fighting between the 2 of us. If you can propose a thread in questions.
(this is mainly due to your better spelling)

:)

MJ

[hassel]

MJ why no flaps? With a full flap landing you have the advantage of the extra drag also g/s being lower when touching down makes the a/c more controllable.
hassel

[mad_jock]

Because i fly in germany and the buggers have trees everywhere as soon as you get below 1000ft its like being in a tumble drier with the turblence and 10-15 knts x-wind is normal. So normally in a warrior we would come at about 85knts no flaps. Chop the power slighly early, stick the nose down into the runway, flare and put it on the deck in a positive manner.

There are also other issues as well to do with upwash / downwash etc which means that the plane is more stable to gusts without flaps. And from a piloting point of view you have to do alot less work on the appr.

I will check this all again to night when i get home to make sure i am not telling porkies about the up and down wash.

MJ



[This message has been edited by mad_jock (edited 18 June 2001).]

[Pontius]

Not specifally the two-seaters, I know, but if you're going to sideslip the 172 don't do it with flap 40. Those big ol' boys can shield the up 7 downy things at the back and really spoil your day. Mind you, unless it's an engine failure, if you're sideslipping and have got flap 40 I think it's probably time to go around and have another go.

Pontius

PS :)on't know if this applies to the new generation 172 or not. I believe (but don't know) that the flaps don't go down that far.

------------------
You Ain't Seen Me - Right !!

[Charlie Foxtrot India]

Is this a sideslip to lose height quickly or a crosswind approach technique?

If it is a crosswind approach technique, then I personally don't like it as it contains the ingredients for a good prang: low, slow and out of balance. At least with the crab technique you aren't getting into a potential spin situation on final. The aeroplane doesn't know there is a crosswind, why cross it up.

I've seen cessnas placarded with sideslips not to be performed with flaps extended. I'd be most annoyed if people sideslipped my pipers with or without flaps. The only good reason I can think of to sideslip an aircraft with flaps is if you need to get into a very small paddock, and you really know what you are doing.

[mad_jock]

I got taught it for that very reason as an emergency procedure if you have to put down in a tight space.

But really does knock hell out of the plane. Your power settings are going to be higher with the extra drag and you feel it with your arse that the plane is fighting against you.

It will also be weathercocking into the wind and will place a large load on the tail. Which will lead to higher maintence costs.

MJ

[MJR]

Well thats a lively debate, my enqiry is really based on the concern of side slipping a Cessna with 40 deg. of flap my lead to a masking of tail plane with potentially disasterous consequences. Is this so?

I believe I can confirm a couple of points firstly the use of flap can de-stabilise an aircraft because more lift is being produced at the inboard sections of the aircraft.

and secondly I was advised to side slip a Warrior for significant height reduction on finals in a PFL for my commercial GFT.

cheers

MJR

[Lucifer]

On finals for a PFL, hopefully it would be recognised earlier that the aircraft is too high such that it is unnecessary. Same applies on approach if too high=go around.

I did it a few times in early training with my then flight school, and it would never be with full landing flap, and add 5 knots and keep the nose down to prevent stall. I don't know if that is the recognised technique however for a Cessna as that is no longer my aircraft and I was subsequently taught not to use it. Remember also not to exceed the V speed for full control surface deflection.

[OnTheStep]

just a note, i'm in a 172s these days and the flap settings are 10°, 20° and 30°

[schuler_tuned]

i was always taught that anything up to 20deg
in a cess was o/k, otherwise tou can mask the rudder, as already said.having said that
i've slipped a 150 with 40deg of flap after an engine failure climbing out parallel to the field with too much height for a normal approach. made sure the speed was above normal, and those barn doors sorted the rest out on very short finals. mind you it was the wobbliest back-track you ever did see,due to legs of jelly!