Crab, slips, and crossed controls

Stealth Pilot wrote
Sideslips are a very useful tool because they allow you to
substantially increase the drag, which makes you descent like a
plumbers toolbag, but doesnt change the forward speed. so you have no
increased risk of stalling as you wash off the height.

What you have described is the "forward slip". Although control usage
is the same in both, a "side slip" is used to correct for a crosswind,
and a "forward slip" is used to descend more rapidly on final without
having the airspeed increase. If one is not landing, I suppose that it
would just be a "slip".

Airliners normally do not use either because of the increased discomfort
caused the passengers....both being uncoordinated flight.

Amine wrote:
PS: I have read about many cases of jetliners that had to make
emergency descents at abnormally high speeds, but the AC143 seems the
only one to have used the sideslip.

AC 143 was constrained by "touchdown speed" runway length. An "emergency
descent" has no such constraint and therefore is able to use the
aircraft's maximum certificated speed for the descent...far in excess of
what would be possible in an approach/landing situation.

In an engine failure situation, keep it as high as possible for as long
as possible to insure that the field can be reached, and then slip as
much as required to lose the excess altitude without gaining airspeed.

Bob Moore
Flight Instructor ASE-IA
ATP B-707 B-727
PanAm (retired)

Robert Moore schrieb:

What you have described is the "forward slip". Although control usage
is the same in both, a "side slip" is used to correct for a crosswind,
and a "forward slip" is used to descend more rapidly

A slip is a slip is a slip.

I always wondered why so many flight instructors celebrate the art of
making simple things seem complicated. I finally came to the conlusion
that it's to look more impressive to the female students.

Stefan wrote
A slip is a slip is a slip.
I always wondered why so many flight instructors celebrate the art of
making simple things seem complicated. I finally came to the conlusion
that it's to look more impressive to the female students.

From The FAA H-8083-3a, Airplane Flying Handbook

INTENTIONAL SLIPS
A slip occurs when the bank angle of an airplane is too
steep for the existing rate of turn. Unintentional slips
are most often the result of uncoordinated
rudder/aileron application. Intentional slips, however,
are used to dissipate altitude without increasing airspeed,
and/or to adjust airplane ground track during a
crosswind. Intentional slips are especially useful in
forced landings, and in situations where obstacles must
be cleared during approaches to confined areas. A slip
can also be used as an emergency means of rapidly
A slip is a combination of forward movement and
sideward (with respect to the longitudinal axis of the
airplane) movement, the lateral axis being inclined
and the sideward movement being toward the low
end of this axis (low wing). An airplane in a slip is in
fact flying sideways. This results in a change in the
direction the relative wind strikes the airplane. Slips
are characterized by a marked increase in drag and
corresponding decrease in airplane climb, cruise, and
glide performance. It is the increase in drag, however,
that makes it possible for an airplane in a slip to
descend rapidly without an increase in airspeed.

A“sideslip” is entered by lowering a wing and applying
just enough opposite rudder to prevent a turn. In a
sideslip, the airplane’s longitudinal axis remains parallel
to the original flightpath, but the airplane no
longer flies straight ahead. Instead the horizontal
component of wing lift forces the airplane also to
move somewhat sideways toward the low wing.
[Figure 8-12] The amount of slip, and therefore the
rate of sideward movement, is determined by the bank
angle. The steeper the bank—the greater the degree of
slip. As bank angle is increased, however, additional
opposite rudder is required to prevent turning.

A “forward slip” is one in which the airplane’s
direction of motion continues the same as before the
slip was begun. Assuming the airplane is originally
in straight flight, the wing on the side toward which
the slip is to be made should be lowered by use of the
ailerons. Simultaneously, the airplane’s nose must be
yawed in the opposite direction by applying opposite
rudder so that the airplane’s longitudinal axis is at an
angle to its original flightpath. [Figure 8-13] The
degree to which the nose is yawed in the opposite
direction from the bank should be such that the
original ground track is maintained. In a forward slip,
the amount of slip, and therefore the sink rate, is
determined by the bank angle. The steeper the bank—
the steeper the descent.

Rgds Bob Moore

Robert Moore schrieb:

A slip is a slip is a slip.

From The FAA H-8083-3a, Airplane Flying Handbook

Ok, so in the USA there exist several different brands of slips.

In the rest of the world however, a slip is a slip is a slip. Which is
how airplanes see it, too, I suppose.

Stefan wrote in news:9cc9b$48d7b746$54487392
:

Robert Moore schrieb:

A slip is a slip is a slip.

From The FAA H-8083-3a, Airplane Flying Handbook

Ok, so in the USA there exist several different brands of slips.

In the rest of the world however, a slip is a slip is a slip. Which is
how airplanes see it, too, I suppose.


You're full of ****, stefan.

Slips are slips no matter where you are and slips, while aerodynamically
identical have different references.






Bertie

Bertie the Bunyip schrieb:

You're full of ****, stefan.

Still better than completely hollow like you.

Slips are slips no matter where you are and slips, while aerodynamically
identical have different references.

Of course they have different references... visual references, that is:
In one, you look straight ahead, in the other, you look slightly to one
side. I'm fully aware that this difference is enough for simple minded
like you to think they are two different maneuvres.

Stefan wrote in
:

Bertie the Bunyip schrieb:

You're full of ****, stefan.

Still better than completely hollow like you.

Slips are slips no matter where you are and slips, while
aerodynamically identical have different references.

Of course they have different references... visual references, that
is: In one, you look straight ahead, in the other, you look slightly
to one side. I'm fully aware that this difference is enough for simple
minded like you to think they are two different maneuvres.


Yeah, right backpedaling boi.


Bertie

"Bertie the Bunyip" wrote in message
...

Slips are slips no matter where you are and slips, while aerodynamically
identical have different references.

This is one of those aeronautical "discussions" that can go on forever
without a clear winner or loser, unless you can agree on who's definition you
wish to accept. For very basic piloting questions like this, I keep an old copy
of "Stick and Rudder" on the shelf. I found it interesting that Wolfgang
apparently found no need to make a distinction; regardless if done for glidepath
control or landing in a crosswind, he calls them both "sideslips".

Go figure.

Vaughn

"Vaughn Simon" wrote in
:


"Bertie the Bunyip" wrote in message
...

Slips are slips no matter where you are and slips, while
aerodynamically identical have different references.

This is one of those aeronautical "discussions" that can go on
forever
without a clear winner or loser, unless you can agree on who's
definition you wish to accept. For very basic piloting questions like
this, I keep an old copy of "Stick and Rudder" on the shelf. I found
it interesting that Wolfgang apparently found no need to make a
distinction; regardless if done for glidepath control or landing in a
crosswind, he calls them both "sideslips".

Mmm, cept Stefan the cheese nazi has no intention of discussing anythign.


Bertie

"Vaughn Simon" wrote in message
...
|
| "Bertie the Bunyip" wrote in message
| ...
|
| Slips are slips no matter where you are and slips, while aerodynamically
| identical have different references.
|
| This is one of those aeronautical "discussions" that can go on forever
| without a clear winner or loser, unless you can agree on who's definition
you
| wish to accept. For very basic piloting questions like this, I keep an
old copy
| of "Stick and Rudder" on the shelf. I found it interesting that Wolfgang
| apparently found no need to make a distinction; regardless if done for
glidepath
| control or landing in a crosswind, he calls them both "sideslips".
|
| Go figure.
|
| Vaughn
|
|

Does the term forward slip describe a slip? Yes.

Does the term side slip describe a slip? Yes.

Do both requre the same control inputs? Yes.

What next? Will we have pattern turns, cross country turns, sight seeing
turns, high altitude turns etc.