forward slipped in

[Guest floatHigh]

Hi all, I discovered this forum (somehow) while looking for some additional information on side-slipping/forward-slipping and with reference to strong gusty crosswinds.

 

In the theory it didn't sound that hard, but nothing was mentioned about slipping in VERY gusty conditions as well! Another thread for this one I guess.

 

Anyway, I got into flying in recent months after having had Lymphoma (NHL) some 2 years ago and having this treated and cleared. Made me realize there's more to life than just working too hard.

 

As a novice I commenced with GA training and had problems getting medical clearance in time for solo flight (Diamond DA20), ..even though I am currently in full-remission.

 

So I got into the RAA Certificate program and went solo in a SportStar a couple of weeks ago, ..first ever solo in powered aircraft!

 

I must mention that years ago and in my early 20's, I soloed gliders, but as some of you might know, these are VERY different machines!

 

Now just to master these aggressive forward-slips!

 

Cheers,

 

William

 

 

[greggf]

Pleased to see that you started on the right foot - with the best choice in aircraft, the SportStar ;-)

 

Cheers,

 

Gregg

 

 

[Student Pilot]

What's a forward slip? I've only ever sideslipped, I think.

 

 

[Guest floatHigh]

Thanks Gregg,

 

Yes, the SportStar is a fun little aircraft!

 

Student Pilot,

 

The forwardslip is somewhat similar the sideslip. Quote taken from Wikipedia (free Internet Encyclopedia):

 

"The forward slip will change the heading of the aircraft away from the down wing, while retaining the original track (path over the ground) of the aircraft.

 

A forward-slip is useful when a pilot has set up for a landing approach with excessive height or must descend steeply beyond a treeline to touchdown near the start of a short runway. Assuming that the runway is properly lined up the forward slip will allow the aircraft track to be maintained while steepening the descent without adding excessive airspeed. Since the heading is not aligned with the runway, the slip must be removed before touchdown to avoid excessive side loading on the landing gear, and if a cross wind is present an appropriate side slip may be necessary at touchdown as described below.

 

In the United States, student pilots are required to know how to do forward slips before embarking on their first solo flight. The logic is that in the event of an engine failure, the pilot will have to land on the first attempt and will not have the chance to go around if he or she is too high and too fast."

 

 

[Student Pilot]

That's what's always been called a sideslip here. "Forward slips" is a yank expression, they've always had to name something different to everybody else.

 

 

[hihosland]

As I understand it;

 

In the United States flying sylabus the following definitions apply

 

If whilst on descent with the controls crossed the runway is dead ahead and aligned with the aircraft's track then it is a forward slip,

 

If however the runway is at an angle to the aircraft track it is a side slip,

 

there is no difference as far as the aircraft is concerned.

 

Davidh

 

 

[Student Pilot]

With some of the older pommie stuff that didn't have flaps to increase your descent rate so you "Sideslipped".

 

If your flying along with the tail out and in the same direction that is just flying unbalanced or out of balance, there's no reason for doing that apart from bad technique. Prior to the last couple of years there has been no mention of "Forward slips" in this country, when did the yanks redefine the term sideslip?

 

 

[Wilfred]

It was'nt the yanks

 

It was the Poms during WW2

 

A slip is an aerodynamic state where an aircraft is moving sideways as well as forward relative to the oncoming airflow.

 

Two forms are employed, the forward-slip and the sideslip. Aerodynamically these are identical once established, but are entered in different manners and will create different ground tracks and headings relative to those prior to entry

 

 

[Student Pilot]

You still haven't convinced me, a sideslip is a sideslip is a sideslip there isn't anything else only flying out of balance.

 

I enter a sideslip with rudder then feed aileron in to keep the desired angle (or not) of bank.

 

How do you enter a sideslip?

 

If it's different how do you enter a "Forward slip"?

 

If there is a difference when and how would you use either?

 

Where does wikipeadia originate, is it yank?

 

Could you give me a reference to "Forward slips" in any pommie literature or training manuals? I have one or two books (including Airforce training manuals) stacked around and apart from recent yank stuff have found no reference to "Forward slips" in any of them.

 

Regards SP

 

 

[Guest floatHigh]

Guess I will think of this crosswind slip as a non-turning slip then! :)

 

Anyway, they are hard to do when you are having to use full rudder!

 

 

[Yenn]

Having flown today as a passenger in a J230 Jabiru and been on final at about 2 deg approach angle, down below the tree tops, I can see a great need for a slip be it either forward or side.

 

I would like to know how that pilot would cope with an engine failure, where the landing area had a steep approach. Not very well I think.

 

 

[Student Pilot]

Having flown today as a passenger in a J230 Jabiru and been on final at about 2 deg approach angle, down below the tree tops, I can see a great need for a slip be it either forward or side.I would like to know how that pilot would cope with an engine failure, where the landing area had a steep approach. Not very well I think.

I don't know if you were refering to me as "That pilot", I always do close circuits and steep approach's. In most machinery I fly I virtually do glide approach's every landing, a lot with a side slip to wash a bit of speed off towards the end.

 

Do any instructors refer to "Forward slips", Authur time for you to chime in.

 

 

[Guest b1rd]

Interesting topic and I'm new to this stuff so I'm probably completely wrong but isn't a side-slip slipping from side to side with crossed controls alternating while descending forward to bleed forward speed and height.

 

A forward slip would be crabbing forward maintaining the same crabbed attitude ? Both do the same thing ... bleed speed and height without the aid of flaps.

 

 

[Guest Ken deVos]

A good description is presented on the RA-Aus website. Ref: "8.5 The slip as a manoeuvre" at http://www.raa.asn.au/groundschool/umodule8.html#sideslip

 

 

[facthunter]

Forward slips.

 

I'm with you ,student pilot, & I taught people to fly DH 82's before you had to be somebody special to fly one. Maybe I'm missing something but I have never heard of a forward slip. There are sideslips & there are sideslipping turns, that's all. If you are practicing a forced landing, the idea is to remain assured of reaching the field, so as not to hit the upwind fence at flying speed, you sit high till you are assured of getting in, then use flap (or sideslip if you don't have any) to get rid of the excess height. The sideslip itself just makes the aircraft less efficient aerodynamically. To enter a sideslip, you bank the aircraft, and stop the further effect of the bank,(yaw) by applying top rudder to maintain a heading.A bit less rudder (or more bank) & the aircraft describes a turn at the same time. A very satisfying manoeuver if done well. N..

 

 

[Student Pilot]

That's an interesting link Ken, the only mention of a forward slip is what I'd call just a normal crab allowing for a crosswind on final. I don't really agree with sideslip or crabbing in a turn that's also mentioned, that's what gets you into trouble. Apart from a stall turn, all turns should be balanced.

 

I don't know how they can quote that as good practice.

 

 

[facthunter]

Sideslipping.

 

There is no doubt that if the airspeed washes right off, AND you have the controls crossed, as in a sideslip, you are in deep trouble. You are set up for a spin entry. The airspeed should under read, as the pitot is at an angle to the airflow, but you can not be sure how much, so a minumum of plus 5 knots added to normal approach speed (indicated) is your never go under speed. Sideslips done at much higher airspeeds, do not seem to be very effective at steepening the approach angle, and put a high bending load on the fin, and feel terrible. Oddly, The nose (pitch) attitude on some aircraft seems to be slightly higher than normal approach when you are slipping at the correct speed. Precise airspeed control is essential, and since the throttle will be closed, (obviously) the pilot must be very aware of pitch attitude control. Do not attempt this manoevre without proper training and have recent experience as well ...N...

 

 

[Guest floatHigh]

Previously as a glider pilot we were taught the sideslip as a method of steep descent to lose height

 

(when airbrakes/spoilers were not enough, using the wing as the pointer to the runway, with a rudder yaw

 

for re-alignment to runway required before roundout.

 

But most recently when I had a test fly in a Tecnam Echo Super (with CFI Graeme Kennedy from Stawell),

 

the demo I had was for one-wheel touch-and-goes and required the straight in alignment, both track and nose.

 

I guess this is could be regarded as an example of forward slipping, ..just the roundout for crosswind landing.

 

 

[pylon500]

instructors refer to "Forward slips", Authur time for you to chime in.

G'Day Glen,

OK, having read the RAAus link about side and forward slips, I can see some confusion occuring.

 

Quick answer is;

 

The SIDE SLIP is created by holding a wing down (usually into wind) while holding rudder in the opposite direction (crossed controls) the net result being that the aircraft approaches the strip with a steep decent, pointing off at some odd angle (usually downwind).

 

The CRAB APPROACH has the aircraft approach the strip in a wings level attitude with the nose pointing into the crosswind to make up for drift.

 

This requires a bit of delft flying to correct prior to touchdown to avoid drifting off the strip.

 

The FORWARD SLIP is where the aircraft is kept pointing at the strip while banking into the crosswind sufficiently enough to maintain the runway heading.

 

This can be carried all the way through the flare onto the ground, however, in very strong crosswinds, this can bring a wingtip very close to the ground.

 

Pros and cons;

 

A side-slip is for a steep, constant speed approach.

 

A forward slip will let you maintain a runway heading, but will degrade your glide angle.

 

A crab approach will give you the best glide for the conditions, but can be interesting if you don't straighten up quick enough before touchdown in a taildragger, landing crabbed in a trike is not as hairy, but still not good for the plane (or good airmanship).

 

Please forward all instructor fees care of,

 

The Senior Instructor,

 

Sydney Recreational Flying Club,

 

The Oaks.

 

Arthur. ;)

 

ps, Com'on Ian, I need more than 20 minutes to compose these without being logged off all the time.

 

 

[Student Pilot]

OK so a "Forward slip" is just a crossed control approach some teach now instead of a "crabbed" approach for a crosswind on final. The main disadvantage to a crossed control approach is if your flying a very slow approach it ups your stall speed. Also in a very strong crosswind you will run out of control before you get to the runway, I've only ever flown a balanced crabbed approach finishing with a sideslip if I need to lose some height.

 

 

[Guest floatHigh]

Authur,

 

That summing-up sounds pretty good to me! ;)

 

William

 

 

[Ultralights]

sort of makes sense.... forward slip is just maintaining runway heading with aileron instead of rudder in a crosswind condition.... thats my usual crosswind technique anyway...

 

in my first few hrs in the vampire i discovered the vampire is not very good at sideslipping... no rear fuselage to push sideways into the slipstream, to create all that extra drag needed to descend quickly without gaining speed.

 

 

[Guest Ken deVos]

Please forward all instructor fees care of,

The Senior Instructor,

 

Sydney Recreational Flying Club,

 

The Oaks.

 

Arthur. ;)

 

ps, Com'on Ian, I need more than 20 minutes to compose these without being logged off all the time.

Thanks Arthur, you have reinforced my understanding of the sideslip manoeuvre and I will gladly forward the instructor fee.

 

BTW, to avoid being logged off when composing long posts, try using Notepad offline, then simply log on and do a cut and paste of the text.

 

PS: The invoice for this advice is in the mail together with your cheque. ;)

 

 

[Admin]

Unfortunately the "Who is logged on" at the bottom of the forums is related to the time out function so if I extend it past the 20 mins then the "Who is logged on" would become superflous.

 

 

[djpacro]

There is no doubt that if the airspeed washes right off, AND you have the controls crossed, as in a sideslip, you are in deep trouble. You are set up for a spin entry.

Not necessarily, the sideslip is inherently spin resistant. Refer http://www.richstowell.com/ Rich's books & videos. I've taken a number of aeroplanes to the stall in a sideslip and it has been a non-event although, like most things, find out definitely first before you try it "at home".

(I admit to not trying it in a DH82 or 7ECA that I recall.)

 

Skidding turns another matter entirely. Definitely do not try that down low.