Piper PA 20 Gear Alignment

[WFCSAC]

Does any one know what the toe in toe out should measure on a Piper pacer?
Warren

[highflyer]

WFCSAC wrote:
>
> Does any one know what the toe in toe out should measure on a Piper pacer?
> Warren

The desired alignment is perfectly parallel to the aircraft centerline.

If you must err, up to two degrees of toe OUT is less desireable but
acceptable. There is NO acceptable toe IN.

Any toein at all will make the airplane extremely squirrely on the
ground
at speed.

Cheers,

--
HighFlyer
Highflight Aviation Services

[Mark J Grueninger]

highflyer wrote:

Actually I think toe in would make it more stable on the ground. If the
aircraft starts to track other than straight it would tend to correct itself
better with toe in . Also any deflection of the gear with toe in would tend to
straighten the gear out with respect to centerline. Of course I could be
mistaken in my thinking in which case never mind.

Mark G

[Bruce A. Frank]

Conventional logic does not apply. The way the gear flexes combined with
toe-in makes landing speed ground handling very squirrelly. As HF said
'0' degrees is ideal.
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
BAFRANK(at)worldnet.att.net Homebuilt Aircraft Newsletter"
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While trying to find the time to finish mine.

[Richard Buege]

Mark J Grueninger wrote:
>
>
>
> Actually I think toe in would make it more stable on the ground.

Mark, draw a diagram with toe in and one wing low. The toe in will
attempt to take the plane away from the low wing, just aggravating an
already less than ideal situation. Toe out will tend to take it towards
the low wing, and help to bring things back to an even keel.

Richard B.

[Joe Norris]

> Actually I think toe in would make it more stable on the ground.

Nope, it don't work that way. If the plane gets up on one wheel that's toed
in, that wheel will attempt to "tuck" under the plane, thus aggravating an
already exciting situation. Toed out gear will tend to pull the gear out
from under the fuselage, which will make things much less dramatic.

Joe

[highflyer]

Mark J Grueninger wrote:
>
> highflyer wrote:
>
> > WFCSAC wrote:
> > >
> > > Does any one know what the toe in toe out should measure on a Piper pacer?
> > > Warren
> >
> > The desired alignment is perfectly parallel to the aircraft centerline.
> >
> > If you must err, up to two degrees of toe OUT is less desireable but
> > acceptable. There is NO acceptable toe IN.
> >
> > Any toein at all will make the airplane extremely squirrely on the
> > ground
> > at speed.
> >
> > Cheers,
> >
> > --
> > HighFlyer
> > Highflight Aviation Services
>
> Actually I think toe in would make it more stable on the ground. If the
> aircraft starts to track other than straight it would tend to correct itself
> better with toe in . Also any deflection of the gear with toe in would tend to
> straighten the gear out with respect to centerline. Of course I could be
> mistaken in my thinking in which case never mind.
>
> Mark G

Hi Mark,

I reasoned like you did once about thirty years ago. Tom Thiessen was
aligning the landing gear on his Pitts. Wound up with just a bit of
toe in! It was 'exciting' to land it! One of the MOST interesting
Pitts to land I have ever seen.

We realigned the gear with a smidge of toe out and it settled right down
and tracked like a hero.

When a taildragger starts to swerve on the runway the high CG results
in significant weight transfer to the outside wheel. If you hae toein
the increased authority of that outside wheel tends to cause the
airplane to tighten its turn and head for the tulles.

On the other hand, with toe OUT, the outside wheel is pointing in the
proper direction to broaden the turn. It works like steering into a
skid in a car and reduces the turn arc, easing the weight transfer,
and stabilizing the roll out.

Please, do NOT put toe IN in the gear of a taildragger.

[Whunicut]

L. Pazmany says in his book "Landing Gear Design For Light Aircraft" : " The
author consulted with a number of aeronautical engineers and landing gear
experts. The answers were mixed. Some indicated that with toed out wheels the
wheel on the outside of the turn tends to run straight and counteract the
groundloop. Other opinions were that the toed-in wheels result in more drag
(due to skidding) in the outside wheel, therefore counteract the ground loop.

Essentially the wheels should run straight (zero toe-in) at normal operating
weight."

IMHO, L. Pazmany (my Hero) is the `final word`.

Warren (There are too many dern Warrens in this NG. (grumble, grum..

[Joe Norris]

> Essentially the wheels should run straight (zero toe-in) at normal
operating
> weight."

Yep, I agree. Zero toe is the ideal. However, I guarantee that you'll know
if the wheels are toed in on the very first landing that gets up on one
wheel. It WILL be exciting, and you WILL want to make sure it's not toed in
on the next landing. Been there, done that!! Toed out will not be nearly
as exciting and you might not even think you need to check the gear. It
DOES make a difference!

Joe Norris