Flying Technique Question of the Day

[Jim Vincent]

Tailored towards the newbies:

On final, assuming there is a crosswind and you need to forward or side slip,
does it make a difference which wing is held down, and why?


Jim Vincent
CFIG
N483SZ

[Bob Johnson]

OK, I'll bite -- the down wing will result in a turn into the wind,
resulting in a runway heading path down final. Is a crab in the same
situation preffered/unpreffered/dealer's choice?

BJ

Jim Vincent wrote:
>
> Tailored towards the newbies:
>
> On final, assuming there is a crosswind and you need to forward or side slip,
> does it make a difference which wing is held down, and why?
>
> Jim Vincent
> CFIG
> N483SZ
>

[Robert Bates]

I've always understood that in a stiff crosswind the upwind wing is lowered
in a side-slip in order to 1. help counteract the crosswind, and 2. prevent
a rollover close to the ground.

As for forward slips, regardless of the crosswind, I personally prefer to
lower the wing on the inside of my approach, forcing me to apply rudder
opposite that used on my turn onto final - helping to prevent a spin
condition at low altitude...

-Rob

"Bob Johnson" > wrote in message
...
> OK, I'll bite -- the down wing will result in a turn into the wind,
> resulting in a runway heading path down final. Is a crab in the same
> situation preffered/unpreffered/dealer's choice?
>
> BJ
>
> Jim Vincent wrote:
> >
> > Tailored towards the newbies:
> >
> > On final, assuming there is a crosswind and you need to forward or side
slip,
> > does it make a difference which wing is held down, and why?
> >
> > Jim Vincent
> > CFIG
> > N483SZ
> >

[tango4]

Forward slip ....

Whasat?

I know what a sideslip is but I've never understood this ( American? ) term.
Can't seem to find it in the BGA instructors manual either.

Ian

[Nyal Williams]

"tango4" > wrote in message >...
> Forward slip ....
>
> Whasat?
>
> I know what a sideslip is but I've never understood this ( American? ) term.
> Can't seem to find it in the BGA instructors manual either.
>
> Ian


Don't bother with it; the glider doesn't know the difference. It is a
US mental exercise based on where you are trying to go. A pilot in
the back seat can't tell which one it is until he sees where you end
up.

[Mike Lindsay]

In article >, Judy Ruprecht
> writes
>At 03:24 01 September 2003, Shirley wrote:
>
>>One (side slip) is used to adjust for drift in a
>>crosswind
>
>.. best used on final approach, both the ground track
>and the glider's longitudinal axis are aligned on runway
>heading. (Useful in a 2-33 with x-winds of 15 kts &
>higher - not a swell option on low-wing gliders in
>strong crosswinds.)
>
>> the other (forward slip) is used to increase the angle
>>of >descent...
>
>.. the ground track is aligned on runway heading,
>while the glider's longitudinal axis is decidedly off-kilter.
>(Useful in some gliders to further steepen a full-spoiler
>approach to a short field or deal with spoiler failure.)
>Too much speed and a delayed recovery, however, can
>leave you with a glider cum lawn dart.
>
>
I see. So the two ideas are aerodynamically the same, but what you call
a sideslip is used for cross wind landings and a forward slip for
steepening the glidepath?


>

--
Mike Lindsay

[Shirley]

wrote:

>I hate to admit it, but I don't know the
>difference between a side slip and a
>forward slip. Please walk me through
>exactly what I'm doing with the stick and
>rudder on each one and where the nose
>is pointed.

See Chapter 14 of the SSA Soaring Flight Manual (pp 14-8 - 14-10) -- the two
maneuvers are fully detailed there, and there is also an excellent figure that
illustrates the difference. I am NOT a CFIG, so I urge you to read the
aforementioned paragraphs and/or talk to a CFIG. But VERY briefly, my
understanding is as follows:

Side Slip (for crosswind control): Lower upwind wing, use enough opposite
rudder to keep glider from banking in direction of the wing. Longitudinal axis
is parallel to the straight flight path.

Forward Slip (steepens angle of descent, used to lose excess altitude): Lower
wing, use oppposite rudder to point nose away from the glide path exposing the
front side of the glider to the oncoming air to create more drag (careful to
maintain not increase airspeed and remember ASI will not be correct). Slip
*toward* crosswind if one is present. Longitudinal axis is NOT parallel to the
flight path, but the flight path is straight. Resume normal flight, of course,
before landing (I'm sure you know that, just CMA!!)!

--Shirley

[Nyal Williams]

Mike Lindsay > wrote in message >...
> In article >, Judy Ruprecht
> > writes
> >At 03:24 01 September 2003, Shirley wrote:
> >
> >>One (side slip) is used to adjust for drift in a
> >>crosswind
> >
> >.. best used on final approach, both the ground track
> >and the glider's longitudinal axis are aligned on runway
> >heading. (Useful in a 2-33 with x-winds of 15 kts &
> >higher - not a swell option on low-wing gliders in
> >strong crosswinds.)
> >
> >> the other (forward slip) is used to increase the angle
> >>of >descent...
> >
> >.. the ground track is aligned on runway heading,
> >while the glider's longitudinal axis is decidedly off-kilter.
> >(Useful in some gliders to further steepen a full-spoiler
> >approach to a short field or deal with spoiler failure.)
> >Too much speed and a delayed recovery, however, can
> >leave you with a glider cum lawn dart.
> >
> >
> I see. So the two ideas are aerodynamically the same, but what you call
> a sideslip is used for cross wind landings and a forward slip for
> steepening the glidepath?

Yes, they are aerodynamically the same. Judy's description is
dead-on. Both of them will steepen the glide path, but the latter one
is much more dramatic than the former. I admit to writing a bit of a
troll; it annoys me that the one that keeps the fuselage and the
course line the same is called a side slip, and especially so that the
one in which one is travelling sideways is called a forward slip.

I still insist that the airplane doesn't know the difference except
that one is slipping a greater amount, usually, than the other. A
very gentle "forward slip" will feel just like a healthy "side slip"
if you have your eyes closed.-

[Fred Mueller]

Mike Lindsay > wrote in message >...
<snip>

> I see. So the two ideas are aerodynamically the same, but what you call
> a sideslip is used for cross wind landings and a forward slip for
> steepening the glidepath?
>




In the US, the term "sidelslip" is shorthand for a forward slip to
landing.

A forward slip can be properly done with the low wing into the wind or
not. A sideslip (forward slip to landing), must obviously be done
with the low wing into the wind or you will be unable to align the
longitudinal axis of the glider with the ground track.

Fred

[Duane Eisenbeiss]

"JJ Sinclair" > wrote in message
...
> Yo, Judy & Shirley,
> I hate to admit it, but I don't know the difference between a side slip
and a
> forward slip. Please walk me through exactly what I'm doing with the stick
and
> rudder on each one and where the nose is pointed. When I have used what I
> called a slip, I was turning a left final, just kept the left wing down,
shoved
> in a bunch of right rudder. The nose went right and I added a little more
> rudder if I wanted to make the ship move to the right or took some rudder
out
> if I wanted to move left.
> Thanks,
> JJ Sinclair

If you were flying such that you could not see the ground how would you know
if you were doing a side slip or a forward slip??
Possible answer: The difference between a side slip and a forward slip is
ground track only.

Duane

[Bert Willing]

Ehm, this is a gliding newsgroup, so my answer referred to glider landings,
not fuel-to-noise converters.

--
Bert Willing

ASW20 "TW"


"Andreas Maurer" > a écrit dans le message de
...
> On Mon, 1 Sep 2003 18:24:31 +0200, "Bert Willing"
> > wrote:
>
> >That's correct, although what you described as a forward slip is referred
to
> >in (at least Continental) Europe as side slip, and what you call side
slip
> >is NEVER done at all.
>
> .. at least in gliders. ;)
> >
> >Corrections for crosswind are done by a crab angle. Darwin takes care of
> >those who can't re-align properly during round-out and flare.
>
> .. at least he takes care of their landing gear, prop, engine, and
> pride.
>
>
>
>
>
> Bye
> Andreas

[Stefan]

tango4 wrote:
>
> So my understanding is that an American forward slip is the same as a
> sideslip anywhere else in the world whilst an American sideslip is a shallow
> rest-of-the-world sideslip

Not where I live. Here, I've never heard the term sideslip, we just do
slips. A slip is a slip is a slip, period. You can use it for different
purposes, although using it on final for crosswind corrections with,
say, an ASH 25 is considered a bad idea here.

Stefan

[tango4]

Slip is just short for sideslip as far as I'm concerned. One and the same.

Ian


"Stefan" <"stefan"@mus. INVALID .ch> wrote in message
...
> tango4 wrote:
> >
> > So my understanding is that an American forward slip is the same as a
> > sideslip anywhere else in the world whilst an American sideslip is a
shallow
> > rest-of-the-world sideslip
>
> Not where I live. Here, I've never heard the term sideslip, we just do
> slips. A slip is a slip is a slip, period. You can use it for different
> purposes, although using it on final for crosswind corrections with,
> say, an ASH 25 is considered a bad idea here.
>
> Stefan

[Brian Case]

OK here is the answer to one of my favorite Flight Review Questions:

What is the difference between a side slip and a forward slip?

1. A side slip, is a slip where the aircraft is pointed the direction
you are going and the wings a tipped to compensate for a cross wind or
off center positioning from the runway center line. Side Slips are
used almost exclusevly for cross wind correction and alignment with
the runway.

2. A Forward Slip, is a slip where the aircraft continues on a path
toward the runway, however the aircraft is not generally pointed
anywere near the direction you are going. The wings are tipped to
compensate for the slip and any crosswind and maintain the aircrafts
path toward the runway. They are typically more agressive than a side
slip and are used primarly to disipate energy (Alitude or Airspeed)

Generally a you should only side slip or forward slip during landings,
most any other time you are simply slipping or more correctly flying
uncoordinated.

Brian
CFIIG/ASEL



Stefan <"stefan"@mus. INVALID .ch> wrote in message >...
> tango4 wrote:
> >
> > So my understanding is that an American forward slip is the same as a
> > sideslip anywhere else in the world whilst an American sideslip is a shallow
> > rest-of-the-world sideslip
>
> Not where I live. Here, I've never heard the term sideslip, we just do
> slips. A slip is a slip is a slip, period. You can use it for different
> purposes, although using it on final for crosswind corrections with,
> say, an ASH 25 is considered a bad idea here.
>
> Stefan

[Chris Ashburn]

Nyal Williams wrote:

> "tango4" > wrote in message >...
> > Forward slip ....
> >
> > Whasat?
> >
> > I know what a sideslip is but I've never understood this ( American? ) term.
> > Can't seem to find it in the BGA instructors manual either.
> >
> > Ian
>
> Don't bother with it; the glider doesn't know the difference. It is a
> US mental exercise based on where you are trying to go. A pilot in
> the back seat can't tell which one it is until he sees where you end
> up.

Most of the discussion is correct, the distinction in terminology and is based on
the intent of the pilot.
Having to fly over here in the US, and being asked to do them on biannual flight reviews, I remember
it this way:

A side-slip is when you're flying (ie pointing) forward.
A forward-slip is when you're flying sideways.

Simple and logical ..... NOT.

The weather more than makes up for these minor inconveniences.

Chris

[George William Peter Reinhart]

1. Yes!
2. 'cause yur landin'!

Cheers!

Jim Vincent > wrote in article
>...
> Tailored towards the newbies:
>
> On final, assuming there is a crosswind and you need to forward or side
slip,
> does it make a difference which wing is held down, and why?
>
>
> Jim Vincent
> CFIG
> N483SZ
>
>

[arealman]

Shirley > wrote in message
...
> wrote:
>
> >I hate to admit it, but I don't know the
> >difference between a side slip and a
> >forward slip. Please walk me through
> >exactly what I'm doing with the stick and
> >rudder on each one and where the nose
> >is pointed.
>
> See Chapter 14 of the SSA Soaring Flight Manual (pp 14-8 - 14-10) -- the
two
> maneuvers are fully detailed there, and there is also an excellent figure
that
> illustrates the difference. I am NOT a CFIG, so I urge you to read the
> aforementioned paragraphs and/or talk to a CFIG. But VERY briefly, my
> understanding is as follows:

Seems to me. in English, this is what we call laying off the drift.
>
> Side Slip (for crosswind control): Lower upwind wing, use enough opposite
> rudder to keep glider from banking in direction of the wing. Longitudinal
axis
> is parallel to the straight flight path.

Seems to me. in English, this is what we call laying off the drift.
>
> Forward Slip (steepens angle of descent, used to lose excess altitude):
Lower
> wing, use oppposite rudder to point nose away from the glide path exposing
the
> front side of the glider to the oncoming air to create more drag (careful
to
> maintain not increase airspeed and remember ASI will not be correct). Slip
> *toward* crosswind if one is present. Longitudinal axis is NOT parallel to
the
> flight path, but the flight path is straight. Resume normal flight, of
course,
> before landing (I'm sure you know that, just CMA!!)!

Whereas this is known as the side slip.

Sounds as if the Americans are trying to make something
simple.....complicated

>
> --Shirley
>

[Chris Nicholas]

I find it interesting, and a little surprising, that the SSA manual does
not mention the need to reduce the amount of nose down when slipping, to
avoid an unwanted speed increase. The only clue is for one form of slip
only , which includes the suggestion "(careful to maintain not
increase airspeed and remember ASI will not be correct)".

As the two manouvres (two as perceived in the USA, only one in the UK
albeit with more than one scenario when one might deploy it) are
aerodynamically the same, they need the same care over speed, unless you
are happy to arrive with a HELP - High Energy Landing Problem.

They both, not just "forward slip", need correction to normal flight
before getting close to the ground, unless either flying a very high
wing glider or risking a spectacular end to the flight as the lower
wingtip digs in while the rest is still airborne.

Chris N.

[Ian Johnston]

On Mon, 1 Sep 2003 12:57:47 UTC, (JJ Sinclair) wrote:

: I hate to admit it, but I don't know the difference between a side slip and a
: forward slip.

It seems to be a distinction made only in some parts of the world, and
as far as I can tell depend more on where your head is pointing than
what the glider is doing, aerodynamically.

Ian
--

[Mike Stramba]

> Jim Vincent > wrote in article
> >...
> > Tailored towards the newbies:
> >
> > On final, assuming there is a crosswind and you need to forward or side
> slip,
> > does it make a difference which wing is held down, and why?
> >
> >
> > Jim Vincent
> > CFIG
> > N483SZ
> >
> >

Since you're a CFIG, I' assuming that you already have an answer to
the question, and that you were curious as to what the "newbies" would
answer ?

As the thread seems to have wandered away from your original question,
what is *your* answer to it ? :)

I'm a newbie glider pilot(3 weeks), and a fairly-newbie power-pilot (3
years), and it wasn't till I started gliding that I was told to keep
the "into wind" wing down.

Now the policy at the glider club I am flying at is to change the
direction of the circuit so that the base leg is into the wind. This
means that after turning final, if I need to slip I have to lower the
opposite wing to the one that is already down for the turn to final.
I never did that, as I found it too much workload, and illogical,
especially if I also found that I might need a "slipping turn".

Mike

[Jim Vincent]

> On final, assuming there is a crosswind and you need to forward or side
>> slip,
>> > does it make a difference which wing is held down, and why?

>Since you're a CFIG, I' assuming that you already have an answer to
>the question, and that you were curious as to what the "newbies" would
>answer ?

Just have a minute to give my input since I'm leaving town for the next three
weeks...

You want the wing down into the wind. Too often, if some one is doing a
pattern, they maintain the same bank direction in a slip that they used in the
pattern. You have to be consciously aware of this and know which will be the
"low" wing on final.

The main reason is to correct for cross wind component. If the wind is coming
from the left and you're banked right wing down, there is very little ability
to adjust for the non-constant cross wind.


Jim Vincent
CFIG
N483SZ

[Mike Stramba]

(Marcel Duenner) wrote in message news:
> Hi Mike
>
> First: what do you mean by a "slipping turn" and when would you need
> one?

You've never heard of a slipping turn? Well... it's a turn + a slip,
i.e. the contols are "modulated" so that the flight path is curved, as
in a "normal" turn/bank, but the sink rate is accelerated with top
rudder.

> Second: IMHO you should never start a slip before being fully
> established on final. Separate the two manoeuvres. That also means it
> doesn't matter which direction the last turn had.

I don't see why. Flying should be a "fluid" process. Labelling
"slips", "turns" / banks, etc is useful when learning, but after that
it should all be just called "flying" :)

Mike

[Andy Durbin]

(Marcel Duenner) wrote in message

> Second: IMHO you should never start a slip before being fully
> established on final. Separate the two manoeuvres. That also means it
> doesn't matter which direction the last turn had.
>
> Best regards
> Marcel

Sorry don't agree. If you botched the circuit so that you are too
high on base to get down with airbrakes alone, then slip on base, and
slip in the final turn, and slip on final as required to get down.

This situation is very likely to happen to glider pilots making their
first off airport landing. The tendency is for inexperienced pilots
to be too high and too close in.

Slipping on the base to final turn is also normal practice in
airplanes with no flaps.


Andy (GY)

[Chuck Scrivner]

At 16:06 02 October 2003, Mike Stramba wrote:
(Marcel Duenner) wrote in message
>news:
First: what do you mean by a 'slipping turn' and when
would you need one?

Chuck Writes;
It was required that I demonstrate a slipping turn
for the Practicle exam. It is not difficult. But,
I contend that it should never be necessary. A good
pattern should resolve any altitude adjusment necessary.
If a slip is needed, there should be plenty of time
in the Down Wind, Base or Final areas.

A good turn is a Coordinated turn. A good pattern
leads to a good landing.

I dislike the terms 'top rudder and Bottom rudder'.
They are confusing and easily mistaken by the fledgling
student.

A slipping turn for the Practical test is like Boxing
the Wake. It just demonstrates pilot control abiliities
and serves little purpose for actual flight.

If you HAVE to slip in a turn, you have totally misjudged
your pattern entry, placement and timing.

Slips ARE fun. I really like to 'crank it sideways'.
But, if you are constantly requireing a slip to final,
then you need to work on your landings and visual references.

The 'Forward' Slip on Final (to lose Altitude) should
ideally be with wing low and/or nose with wind. This
allows an (argueably) easier transition to 'Side' Slip
for Cross wind compensation. I find little difference
one way or the other.

Be aware that there is a tendency to lower the nose
when entering a Foward slip to lose altitude.

This is counter productive for all of the 'speeds to
fly' reasons.

Set up your appropriate pattern or final speed. Maintain
the SAME horizon attitude during the Foward slip.
This will give the greatest amount of Altitude lose
for a given distance and your airspeed will remain
constant.
End O' Rant

Chuck
********
>
>You've never heard of a slipping turn? Well... it's
>a turn + a slip,i.e. the contols are 'modulated' so
that the flight path is curved, as in a 'normal' turn/bank,
but the sink rate is accelerated with top rudder.
>
>> Second: IMHO you should never start a slip before
>>being fully
>> established on final. Separate the two manoeuvres.
>>That also means it> doesn't matter which direction the
>last turn had.
>
>I don't see why. Flying should be a 'fluid' process.
>Labelling
>'slips', 'turns' / banks, etc is useful when learning,
>but after that
>it should all be just called 'flying' :)
>
>Mike
>

[Marcel Duenner]

(Andy Durbin) wrote in message >...
> (Marcel Duenner) wrote in message
>
> > Second: IMHO you should never start a slip before being fully
> > established on final. Separate the two manoeuvres. That also means it
> > doesn't matter which direction the last turn had.
> >
> > Best regards
> > Marcel
>
> Sorry don't agree. If you botched the circuit so that you are too
> high on base to get down with airbrakes alone, then slip on base, and
> slip in the final turn, and slip on final as required to get down.
>
> This situation is very likely to happen to glider pilots making their
> first off airport landing. The tendency is for inexperienced pilots
> to be too high and too close in.
>
> Slipping on the base to final turn is also normal practice in
> airplanes with no flaps.
>
>
> Andy (GY)

OK, I agree that would be a situation to need a slipping turn. I do
not agree, however, that it is "very likely to happen to glider pilots
making their first off airport landing". If it is very likely, there
was something wrong with the training. It certainly should never
happen on an airfield. If someone misjudges that badly he should not
be flying solo.

Mike has only been flying gliders for three weeks so I think it would
be easier for him to fly the manoeuvres sequentially until he doesn't
have to think about control co-ordination anymore.

Regards
Marcel