Slips and skids

I have heard definitions for both, but I'm still confused. Anyone
care to elaborate?

Wil

On Mar 16, 9:38*am, William Hung wrote:
I have heard definitions for both, but I'm still confused. *Anyone
care to elaborate?


In a skid the ball is deflected to the outside of the turn and in a
slip it's to the inside. Since you "step on the ball" with the rudder,
it foillows that a skid occurs when there is too much yaw in the
direction of turn (like a car rear end breaking away) and a slip when
there is not enough.

Hope this helps.

Cheers.

On Mar 15, 7:49*pm, WingFlaps wrote:
On Mar 16, 9:38*am, William Hung wrote:

I have heard definitions for both, but I'm still confused. *Anyone
care to elaborate?

In a skid the ball is deflected to the outside of the turn and in a
slip it's to the inside. Since you "step on the ball" with the rudder,
it foillows that a skid occurs when there is too much yaw in the
direction of turn (like a car rear end breaking away) and a slip when
there is not enough.

Hope this helps.

Cheers.

Heh.

Except when the control system is misrigged like a plane I flew
recently. In order to get a coordinated turn, I had to give "top"
rudder in a turn. That's wrong.

Of course the actual rudder must have been bottom, but, it was bad.

If you want a great explanation (and a GREAT) book on flying, get Rich
Stowell's "Emergency Maneuver Training". It has nice drawings
illusatrating rudder and aileron positions in both slip and skid. Plus
an explanation about why your life depends on knowing the difference
when you're in the pattern or otherwise low to the ground and at
relative high AoA.

On Sat, 15 Mar 2008 13:38:20 -0700 (PDT), William Hung
wrote:

I have heard definitions for both, but I'm still confused. Anyone
care to elaborate?

To me the easiest analogy is to think of a road that has a steep
banked turn covered with ice. If you go around it too fast you will
"skid" to the outside. If you go too slow you will slip down hill to
the inside.

In the case of the airplane too much rudder to the inside will make
you fell like you are being pushed to the outside and the plane will
be skidding to the outside.

Not enough rudder and the nose will drop in the turn. so you add
rudder to raise the nose and you feel like you are pressed against the
lower side of the plane which is now slipping down hill.


Wil
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Not enough rudder and the nose will drop in the turn. so you add
rudder to raise the nose and you feel like you are pressed against the
lower side of the plane which is now slipping down hill.


Are you sure?

I think the more bottom rudder you give in a turn, the more the nose
will appear to move lower against a given horizon. All the rudder does
is pull the plane around an axis from ear-to-ear. So if you give too
much bottom rudder, the nose will appear to drop in a turn. If you
give top rudder, you'll have the nose "rise" against the turn.

The classic case of skid is when too much bottom rudder is given, the
nose swings around the ear-to-ear axis, yawing past coordinated turn;
and if the pilot pulls back on the elevator to "raise" the nose back
up, it increases AoA, things could be getting dangerous ...

On Sat, 15 Mar 2008 22:57:41 -0700 (PDT),
wrote:

Not enough rudder and the nose will drop in the turn. so you add
rudder to raise the nose and you feel like you are pressed against the
lower side of the plane which is now slipping down hill.


Are you sure?

I phrased tht badly but it is an anology. Stick with the car on the
sliper y road:-))


I think the more bottom rudder you give in a turn, the more the nose
will appear to move lower against a given horizon. All the rudder does
is pull the plane around an axis from ear-to-ear. So if you give too
much bottom rudder, the nose will appear to drop in a turn. If you
give top rudder, you'll have the nose "rise" against the turn.

The classic case of skid is when too much bottom rudder is given, the
nose swings around the ear-to-ear axis, yawing past coordinated turn;
and if the pilot pulls back on the elevator to "raise" the nose back
up, it increases AoA, things could be getting dangerous ...
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

You guys are talking about airplanes. You have to think about all the other
factors associated with engines, like "p" factor and torque, and then wing
wash in and out, offset rudder, etc. Then consider the differences in
shallow, medium and steep turns (please look up the definitions, if it's
unclear) where control forces are again difference. It is helpful to take
some glider lessons which removes some of these variables.

In an airplane, holding top rudder in a turn was probably not your
imagination. In one direction this is normal and you can experience it also
in one end of the Lazy eight exercise. I think it is also a commercial
written exam question and It will almost certainly come up on the commercial
oral. Hint: Think "P' factor, low speed, high angle of attack, high power
setting. I'll leave it to you guys to discuss this further.

--
BobF.
"Roger" wrote in message
news
On Sat, 15 Mar 2008 22:57:41 -0700 (PDT),
wrote:

Not enough rudder and the nose will drop in the turn. so you add
rudder to raise the nose and you feel like you are pressed against the
lower side of the plane which is now slipping down hill.


Are you sure?

I phrased tht badly but it is an anology. Stick with the car on the
sliper y road:-))


I think the more bottom rudder you give in a turn, the more the nose
will appear to move lower against a given horizon. All the rudder does
is pull the plane around an axis from ear-to-ear. So if you give too
much bottom rudder, the nose will appear to drop in a turn. If you
give top rudder, you'll have the nose "rise" against the turn.

The classic case of skid is when too much bottom rudder is given, the
nose swings around the ear-to-ear axis, yawing past coordinated turn;
and if the pilot pulls back on the elevator to "raise" the nose back
up, it increases AoA, things could be getting dangerous ...
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Mar 15, 10:57 pm, wrote:

I think the more bottom rudder you give in a turn, the more the nose
will appear to move lower against a given horizon. All the rudder does
is pull the plane around an axis from ear-to-ear.

The rudder is intended to control adverse yaw, not to turn the
airplane. Banking the airplane turns it. Some airplanes, the "idiot-
proof" ones, sometimes need no rudder at all in a turn.

Dan

On Mar 15, 9:23 pm, wrote:

Except when the control system is misrigged like a plane I flew
recently. In order to get a coordinated turn, I had to give "top"
rudder in a turn. That's wrong.

Is that the one in which I suggested a broken rudder bar spring?
Anything come of that?

Dan

On Mar 16, 3:41 pm, wrote:
On Mar 15, 10:57 pm, wrote:

I think the more bottom rudder you give in a turn, the more the nose
will appear to move lower against a given horizon. All the rudder does
is pull the plane around an axis from ear-to-ear.

The rudder is intended to control adverse yaw, not to turn the
airplane. Banking the airplane turns it. Some airplanes, the "idiot-
proof" ones, sometimes need no rudder at all in a turn.

Dan

Actually, I beg to differ. Banking rotates the airplane about its
longitudinal axis. Yawing rotates about its vertical axis. Neither of
these causes the airplane to change heading. It is the aerodynamic
forces that streamlines the airplane with the relative wind is what
makes it turn (ie weather vaning).

For comparison, think of the space shuttle banking or yawing in orbit.
This does not change its heading because there is no streamlining
effect.