Side-slipping

[Tiddles]

Does anyone have any views on how effective side-slipping in a Piper Cherokee 180C is as a means of losing height rapidly. Or if there is a preferred method I would be interested to know (e.g. spiral dive?).

I have tried side-slipping and the Cherokee does not seem to be very comfortable doing this - you do get a respectable rate of descent however.

What are the forces on the airplane when side-slipping - any issues/techniques to be aware of (bits falling off etc)?

Thanks

[juswonnafly]

Try this........

close throttle, full flap, point down! Keep the speed just below flap limiting speed..................fantastic!:)

JWF

[Flash0710]

Well,

I have sucessfully sideslipped a pa28 and had no problems

I believe that there are certain machines that side slipping is an issue as various control sufaces are blanked but this seems to present no problem in a pa28.

I was taught c 1996 by my insructor to side slip

When working for a flying school side slipping was not in the syllabus

They felt their students should fly a perfect approach every time we all know in truth we all screw up and side slipping at times can be an extremely useful tool

.........Waiting to be shot down...........:rolleyes:

[Flyin'Dutch']

Cant remember if I have flown a 180C without looking in the logbook but the PA28's that I have slipped come down quite nicely when applying a slip.

You dont mention your experience and from what I read between the lines (correct me if I am wrong) you may well not have a lot of experience and that may be the issue.

As others have stated some machines are not allowed to slip and this should be explicitly be mentioned in the POH.

If it is an experience issue you would best find an instructor that can show you how to properly slip an aeroplane. To be honest I think that need not necessisarily be in a PA28 (although it would not hurt) Slipping is a bit like riding a bike or driving a car. Once mastered the skill is readily transferable between mounts.

Most difficult bit of the training is probably going to be finding an instructor that can teach you this properly.

Have fun.

FD

[Doghouse]

Grab an instructor for the side-slipping training - it's often left out of the PPL training (should be in descending part 2).

I'm not a big fan of slipping the PA28's as I don't think you get high enough rates of descent (even with full flap). Bigger rudder needed? I prefer S turns, particularly in the Cherokee which can sink really well.

I'm clueless about the aerodynamic forces involved - there are certain control surface blanking issues with side-slips in some aircraft (eg I believe Cessna's with full flap) but that would be written in the POH.

Main thing to watch out for is pitot/static instruments as airflow into vents is disturbed. Some ASI's will give false readings in the side-slip.

If poss. get yourself into a Cub, Tigermoth or even an Extra if you've got loads of dough. These slip really well.

[GRP]

Dunno about the Cherokee 180 but the Arrow POH has as its very last entry....

"Prolonged slips or skids which result in excess of 2000 ft of altitude loss, or other radical or extreme maneuvers which could cause uncovering of the fuel outlet must be avoided as fuel flow interruption may occur when tank being used is not full"

I don't normally find myself spouting contents of the flight manual but I happen to have just read through mine yesterday.

Not sure why it mentions 2000 ft of altitude so specifically. I *think* what this is saying that if you have an emptyish tank and hold a slip long enough then the fuel can slosh away from the tank outlet and stop your engine running!

[englishal]

I believe the POH for most PA28's state that you should NOT sideslip with extended flaps...[I may be getting mixed up with a 172, haven't got a POH to hand].

You should be able to get a good rate of decent in a slip in a PA28 without exceeding any design limitations. Can also be useful if you have other problems, for example wing fire [unlikely:p ], trying to put an engine fire out or can't see out of the window becasue crap is coming out from under the bonnet.

Some Emergency decent procedures are specific, for example the P28R emergency decent is basically cut throttle, prop forward, flaps extend, gear down, pitch down to top of white arc and decending fairly steep turn. This will get you down very quick.

Check the POH for your aircrafts emergency decent procedure...

Cheers
EA:D

[No. 2]

Tiddles,

Regarding your question about the forces acting on the aircraft, consider a pilot about to carry out a sideslip manoeuvre to lose height with the left wing down. With the arcraft banked a component of weight will cause a sideslip resulting in a sideways airflow onto the fin and the fuselage. The relative airflow on the fin will try and turn the aircraft in the same direction as the dropped wing. The pilot counteracts this tendancy for the nose to turn by applying right rudder. The force on the fuselage is generally in the opposite direction to that of the fin and will assist the pilot in preventing the nose turning; it is however, not as significant as the sideways force on the fin. All this will result in the aircraft being out of balance and consequently an increase in drag will occur which is what allows the aircraft to descend more rapidly.

The use of full flaps on some aircraft types is not advised during the sideslip because it distrubs the airflow and causes blanketing of the elevator reducing its effectiveness. There may also be other reasons too?

As mentioned above, another way to lose height would be to apply flaps and point the nose down. However, you'll then get an unwanted build up of airspeed, so alternatively you could raise the nose instead and descend with a high angle of attack and lower airspeed.

No. 2

[kabz]

hmmm, I just made very effective of a slip in a 172 to make it into a runway when the engine 'weren't right'...

used it to lose about a 1000 surplus feet, just pushed the left pedal as hard as I could and steered with the yoke.

Main thing with a slip is to not accidentally pitch forward and gain a load of airspeed, and just be real steady with it.

It can be a great tool in the armoury when you need it, and I gave silent thanks to my instructors (glider and power) when I got my stricken 172 back on terra firma...

Ohhh, the DRAMA !!!!! :=

[LowNSlow]

kabz hope you didn't have full flap down cos the POH on some 172's says not to do it. Under certain circumstances the nose will drop rapidly as the tailplane enters the turbulent air caused by the flaps and loses lift.

[Flyin'Dutch']

LownSlow

Take it your comment was a bit tongue in cheek.

I think in the situation that KABZ was in he found that it would have been best to ignore that piece of info in the POH.

His thread is on this page as well.

Well done KABZ for getting man and machine back in one piece.

FD

The tailplane of an aeroplane in a slip produces negative lift to create a downforce. If this is 'lost' the only thing that will happen is that the machine will pitch down and the aeroplane will pick up speed and thus terminate the slip. Nowt more.

[LowNSlow]

fd I congratulated kabz on the thread he started regarding his emergency. He obviously did what was necessary at the time. :cool:

I think ignoring sections of an aircraft's POH is done at your own risk regardless of the circumstances. Apart from invalidating your insurance, it can also kill you. As I understand it, in the 172 with full flap down, a steep sideslip can result in a very rapid nose down and tuck under. I've not tried it myself but have been assured that it can be quite violent depending on the c of g. It's not something I'd like if I was in a semi-glide at 200' with no chance of regaining height with power. :eek:

[Flyin'Dutch']

Hey, chill out......

I agree with you entirely. However; that particular part of the 172 handbook for certain versions was (I have been told) more as a result of the sales and legal folk wanting this in, rather than something that was potentially dangerous.

Not all 172s have this restriction.

Sometimes in life you have to throw the book out and do what is right at that moment.

If you read KABZ' post he was not at 200 foot. He needed to shed a 1000+

He has obviously mastered the sideslipping skill well.

QED.

From your post I gather that you have no/limited experience in slipping gliders. No recovery with engine there.

The best ones are right down to the deck with only easing off the slip and the backpressure for the flare, one fluid motion. Grand to do and grand to watch.

Not for beginners tho'

:eek:

FD

[mgc]

just done side slipping as part of ppl on a 150, full flap max crosswind all the way in. Instructors recommended method, very effective::D

[LowNSlow]

Flyin'Dutch if I came across a bit strong, I apologise. I agree that in some circumstances you might need to bin the book and yes I forget the 1000' required height loss!

I was told by someone who had tried it that the early (Conti engined) 172's did indeed have a very marked nose drop in a steep sideslip.

You are spot on regarding sideslipping gliders, I have no experience of that at all. I have been known to prefer slipping Cubs and Austers into short grass fields though ;)

[Tiddles]

Thanks for all the replies - a lot of useful info and views. The full flap and nose down seems to be a good one to investigate (with a beady eye on the white arc).

With regard to experience (see reply above) I do have 400+ hours (330+ P1) mainly on PA28s but never really had to lose height rapidly. I am going through an 'experimental' phase at the moment to liven up the flying (not sure you can do too much of that in a Cherokee!).

Once again thanks ;)

[Saab Dastard]

Learning to sideslip a PA28 properly with an instructor greatly increased my confidence in carrying out PFLs. I then passed that section of the skills test that had been outstanding since last October!

He also demonstrated some serious S-turns on final which scared the s**t out of me! I'll stick to slipping if I need to lose height - perhaps not so efficient or graceful, but saves on the laundry bills ;)

SD

[Doghouse]

If you want to lose a lot of height in the PA28 'in an emergency' then I don't think side slipping's the answer - you just don't lost height fast enough. I've had a badly rough running engine and came in high on the approach - thought I could slip it in once I cleared a town, but it didn't come down. Had to put in some big S turns and aircraft responded well. Remember with high angles of bank in the glide you need to increase your speed.

The technique of dumping the nose is okay, it relies on parasite drag stopping the speed running away - works brilliantly on something like the Arrow.

One trick you can try is coming in too low on the glide. Assuming the aircraft's clean, keep your speed up and with 20 ft to go dump all the flap - that'll make you balloon and clear a hedge or obstacle. Works really well in PA28.