Flying Technique Question of the Day

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

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

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

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

"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.

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

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

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.-

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

"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