Rudder for final runway alignment (?)

Is it cheating/advisable/forbidden/useless to use the rudder alone to
accomplish the very last seconds of runway alignment on landing? As I
approach the landing point it becomes very difficult to turn in the
usual way just to improve alignment. Using rudder alone can line me
up perfectly right quick, but I don't know if that's the proper
technique, and I have to hold the rudder going in.

I know that the rudder can (and should?) be used to deal with
crosswinds, but I'm talking about landing in calm air and just being
an aircraft-width or so away from the centerline (which on narrow
runways or with large aircraft might mean one set of wheels on the
grass). As I get closer I'm afraid to roll the aircraft because a
wing might fall too low, or ground effect might do something
unpleasant, or something like that.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Are you talking about computer games or flying a real airplane?

The flight model of a lot of games does not come close to the real thing
unless you are using one that requires a work station to run.

I don't think that would work very well. If the aircraft is already
lined up with the runway heading, using rudder to move the aircraft
laterally will cause you touchdown in a crab. You should use the
aileron to manuever the plan laterally and use the rudder to keep the
nose pointing to the runway heading, the same way you do in a cross
wind landing. If the runway is very long, add a little bit power when
you do this so you'll have a bit more time. If the runway is short and
you doubt that you can get it straighten out, go around.

The fear of banking the plane close to ground is misplaced. It's
actually easier to do a smoother touchdown when one wheel touches the
ground first, even if it's a bit firm. That's because a single wheel
firm touch-down will cause the plane to roll to the other direction (so
the other wheel will also touch shortly after), and that rolling motion
absorbs some of the energy caused by a firm touchdown and make it feels
less firm.

Mxsmanic wrote:


I know that the rudder can (and should?) be used to deal with
crosswinds, but I'm talking about landing in calm air and just being
an aircraft-width or so away from the centerline (which on narrow
runways or with large aircraft might mean one set of wheels on the
grass). As I get closer I'm afraid to roll the aircraft because a
wing might fall too low, or ground effect might do something
unpleasant, or something like that.

--
Transpose mxsmanic and gmail to reach me by e-mail.

i know you're doing this on a machine and i don't know how it's set up
but with high wing light aircraft ( my only experience) you really can
only move the airplane track left or right with ailerons. punching the
rudders just moves the nose left or right. now, that's short-term.
eventually, the rudder will send the airplane left or right but that
takes a while. kinda like skidding around a turn in a car. also, on a
high wing at least, you've got a lot of room to push it over before you
have a wing hit the runway (or light or weeds or whatever). if the body
of the aircraft is already over the runway but the nose isn't then
"kicking it in" with the rudder is standard.

good luck

dan
Mxsmanic wrote:
Is it cheating/advisable/forbidden/useless to use the rudder alone to
accomplish the very last seconds of runway alignment on landing? As I
approach the landing point it becomes very difficult to turn in the
usual way just to improve alignment. Using rudder alone can line me
up perfectly right quick, but I don't know if that's the proper
technique, and I have to hold the rudder going in.

I know that the rudder can (and should?) be used to deal with
crosswinds, but I'm talking about landing in calm air and just being
an aircraft-width or so away from the centerline (which on narrow
runways or with large aircraft might mean one set of wheels on the
grass). As I get closer I'm afraid to roll the aircraft because a
wing might fall too low, or ground effect might do something
unpleasant, or something like that.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Even in calm winds pilots use the same techniques to "slide" over to
the runway they use in a cross wind. In truth you probably don't know
if your lack of alignment is a result of cross wind or poor roll out.
The two techniques used are "crab" in which you hold the nose into the
wind and the kick it out before touch down and "slip" in which you hold
the up wind wing down and hold the nose in ailgnment with the runway
using rudder. There are pro's and con's to each. The "crab and kick" is
pretty much the only way to go in aircraft with swept back wings
because they aren't excited about slipping and taught by ex-military
and airline instructors. The "slip" is pretty much the only way to go
with light tailwheel planes because it takes near superhuman ability to
straighten these aircraft on the runway after an upset as extream as
the "kick". Planes in between can go either way.

-Robert, CFII

No it is not cheating. Many airplanes cannot use a wing down method for
x-wind landing. This is because their engines would scrape the runway.

Karl



"Mxsmanic" wrote in message
...
Is it cheating/advisable/forbidden/useless to use the rudder alone to
accomplish the very last seconds of runway alignment on landing? As I
approach the landing point it becomes very difficult to turn in the
usual way just to improve alignment. Using rudder alone can line me
up perfectly right quick, but I don't know if that's the proper
technique, and I have to hold the rudder going in.

I know that the rudder can (and should?) be used to deal with
crosswinds, but I'm talking about landing in calm air and just being
an aircraft-width or so away from the centerline (which on narrow
runways or with large aircraft might mean one set of wheels on the
grass). As I get closer I'm afraid to roll the aircraft because a
wing might fall too low, or ground effect might do something
unpleasant, or something like that.

--
Transpose mxsmanic and gmail to reach me by e-mail.

On Wed, 20 Sep 2006 17:46:08 +0200, Mxsmanic
wrote:

Is it cheating/advisable/forbidden/useless to use the rudder alone to
accomplish the very last seconds of runway alignment on landing?

Some argue that it's preferable to use the rudder in an instrument
approach for minor heading changes. In fact, when I took my instrument
rating check ride, the examiner chided me for rolling to minor heading
changes instead of just using the rudder, though he signed me off
anyway. After reading Langewiesche ("Stick and Rudder") I concluded
that it's preferable to use coordinated turns to help avoid
disorienting the inner ear. Personal preference. The choice may also
depend upon the airplane.

I know that the rudder can (and should?) be used to deal with
crosswinds, but I'm talking about landing in calm air and just being
an aircraft-width or so away from the centerline (which on narrow
runways or with large aircraft might mean one set of wheels on the
grass). As I get closer I'm afraid to roll the aircraft because a
wing might fall too low, or ground effect might do something
unpleasant, or something like that.

IRL, by the time that you're that close to touchdown, you ought to
already have heading and centerline alignment pretty well nailed. If
you're worried about dragging a wing, landing in the grass, or
knocking over the glideslope transmitter or something, then your
approach is so out of shape that you probably ought to miss it and go
around.

RK Henry

"Mxsmanic" wrote in message
...
Is it cheating/advisable/forbidden/useless to use the rudder alone to
accomplish the very last seconds of runway alignment on landing? As I
approach the landing point it becomes very difficult to turn in the
usual way just to improve alignment. Using rudder alone can line me
up perfectly right quick, but I don't know if that's the proper
technique, and I have to hold the rudder going in.

I know that the rudder can (and should?) be used to deal with
crosswinds, but I'm talking about landing in calm air and just being
an aircraft-width or so away from the centerline (which on narrow
runways or with large aircraft might mean one set of wheels on the
grass). As I get closer I'm afraid to roll the aircraft because a
wing might fall too low, or ground effect might do something
unpleasant, or something like that.

The actual line up just prior to touchdown is a marriage of subtle control
pressures dealing with several things at one time. Depending on the airplane
you're flying, the amount of bank available to you at the last second might
well be limited as you have noted. For many airplanes, it is perfectly
acceptable and indeed can even be critical to use rudder to insure
proper alignment of the aircraft with the runway at touchdown.
Its probably not wise to consider the act of touchdown as a 0 wind
condition. Although it is possible to actually have a 0 wind condition, in
reality, you will almost always have some wind component acting on the
airplane through the touchdown. That's why landing an airplane is considered
the marriage of all your controls acting at once to achieve the touchdown
correctly.
Some airplanes like airliners for example with underslung engines can't be
banked close to the ground. Others like the F16 or the T38, require a
straight in crab, set up for whatever is necessary, right through the
landing.
Generally, you will set up a landing with whatever the airplane is telling
you is needed at any given instant in time during the approach and the flare
through touchdown. If its truly calm, its a simple line up and landing. If
needed, you can use whatever combination of crab or slip and correction from
the slip through touchdown. Remember, its aircraft specific!
To answer your question, generally yes, you can, and indeed should, use
rudder to align the airplane at touchdown. General rule; keep the tail lined
up with the nose and don't scuff the wheels with a side load and you're
right in the ball park.
Dudley Henriques

RK Henry writes:

Some argue that it's preferable to use the rudder in an instrument
approach for minor heading changes. In fact, when I took my instrument
rating check ride, the examiner chided me for rolling to minor heading
changes instead of just using the rudder, though he signed me off
anyway.

If I try to use the rudder alone for a heading change in flight, the
aircraft just snaps back to its previous heading when I center the
rudder again.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Viperdoc,

Are you talking about computer games or flying a real airplane?


Haven't you read his postings? He doesn't fly, doesn't want to, insists
he can't afford to, thinks it is dangerous, unpleasant and so on. This
guy is NEVER talking about flying.

--
Thomas Borchert (EDDH)