taildragger toe-in vs toe-out AGAIN

On Sat, 15 Nov 2003 17:56:40 GMT, Dave Hyde wrote:

My hypothesis is that the sloppy spring links let you get a bunch of
rudder deflection before you get much tailwheel deflection, and this
is good at, say, 40MPH and above.

This is interesting. One of the things my inspector asked
me to fix was the slop in the tailwheel springs. I got
almost all of it out, and the airplane handles very well
on the ground, but I haven't had it up to 40 mph yet. I've
flown two RV's with loose springs and I thought mine handled
better at low speed, but that may just be wishful thinking.
I've seen lots of recommendations from RV people to make sure
there's at least a little slack in the springs, and I don't
recall ever seeing any RV-flyer recommend NO slack.

My head hurts :-)

Dave 'still ground-bound' Hyde
++++++++++++++++++++++++++++

Your setup is fine...
for NO wind or wind STRAIGHT down the runway.

In a crosswind with CONTROLS CROSSED and
you're about to 3 point... guess what you got?

Yep... a rudder AND a tailwheel aimed towards
the boondocks. The stronger the crosswind,
the more problematic this can become.
depending on a lot of factors....
including one's experience level.

The following is my GENERAL statement:

YMMV.

For the most pleasant transition....
The aircraft needs springs that can yield
sufficiently in a timely manner, some 'slack'
to ameliorate this golly-woppled condition
or a combination of both. A lot of the setup
depends on pilot preferences.

Can one do without the above suggestions?
Sure. Beat your head against the wall, too.
That's my 2 cents - given many, many tailwheel
years and hours and I'm sticking to it. g

P.S.
Let me add... it's as much 'art' as science.


Barnyard BOb - no advocate of wheel landings

I think all this toein/toeout stuff comes into play before the tailwheel is
even down.--
walt evans
NX140DL

"Stealth Pilot" wrote in message
...
I should add that in the considerations regarding handling of a
taildragger tyre pressure and tailwheel alignment and gearing are
quite critical as well.

25psi on my tailwind has as much bearing as anything regarding
handling. below 25psi and it is directionally interesting, much above
25psi and it is a bugger to land but very easy to bounce, and bounce,
and bounce.

having the neutral point of the rudder and tailwheel together is
critical. if they are offset from each other you get this very
squirrelly roll out as one has effect, then the other, then the other
until you finally run out of rudder.

the gearing of the tailwheel is important to relaxed landing as well.
having the tailwheel overgeared makes the landing a nightmare.
I tamed mine by moving the link arm in to about half the prior
distance where it attaches to the rudder.


these are all items just as important as toe in/out when considering
taildragger gear.

Stealth Pilot

btw how anyone lands a taildragger with sloppy spring links to the
tailwheel is beyond me.

On Mon, 17 Nov 2003 17:37:52 -0500, "w b evans"
wrote:

I think all this toein/toeout stuff comes into play before the tailwheel is
even down.--
walt evans
NX140DL

comes into play at any time you get the aircraft off line and are
recovering to straight. regardless of where the tailwheel is.
if you keep it dead straight it is all insignificant.
Stealth Pilot

On 14 Nov 2003 10:07:59 -0800, (Joa) wrote:

to directly answer your questions...

Granted these are set
without weight on the aircraft and the toe-in may change slightly when
under load.

that is a very important issue. what the legs are set at without load
is irrelevant. it is the position of the wheel under load that is of
critical importance. tapered spring legs will behave differently to
pivoting arms which will be different from linear compression legs
with scissor guides. (tailwind vs Auster vs jodel)

I think it boils down to what wins when you start to go into a turn
with a taildragger- does the toed-in outside wheel "drag" and thus
want to straighten you back out or does the toed-out outside wheel get
weight transferred to it and tend to straighten you out (vs tightening
the turn)?

see my other post but I will make the comment that the way a toed in
wheel behaves is entirely dependent on the surface itr is rolling on.
it is likely to be manageable on grass because of the unherent sliding
that makes grass so much of a pleasure to land on.
a wheel with toe in on bitumen would be a decided handful because it
would track in the direction that it was pointed. there is very little
slippage experienced on bitumen which makes the requirements for
alignment before touchdown just that much more critical.

the key to avoiding groundloops is to land straight. dont let them set
up in the first place.

in heavy crosswinds I not averse to landing on the into wind wheel and
tailwheel and holding the wing down. I dont know what that does to the
geometry.

Anybody with some definite answers based on physics?

what I've written is demonstrated physics with my aircraft.

There's lots of
emperical and experiential opinions out there, anybody with some more
factual answers to the argument?

when you start out flying a taildragger dont underestimate the
difficulty, but dont over estimate it either.
learn to fly in ideal conditions. then as experience builds venture
gradually into less ideal conditions. you'll probably scare yourself a
few times and that is healthy. if you persist and master it you'll be
able to handle windsock horizontal conditions with confidence (you may
not enjoy them but you will be capable).

the opportunities for error until you master taildraggers are
considerable.
get yourself an experienced instructor to guide you through the first
few hours and you will be set for life.

be chastened by the example of the astronaut doctor who died in a
Tailwind. press on the wrong foot while correcting and it can be all
over in an instant.

Stealth Pilot

On Fri, 14 Nov 2003 10:07:59 -0800, Joa wrote:

OK, I've researched this a fair bit and am still hearing two definite
different views. One one hand you have those that swear you need
toe-out and then on the other you have (among others- these are the
few I'm certain about) Cessna 100 series, Huskies, and Pitt's that all
are set with slight toe-in by the factory. Granted these are set
without weight on the aircraft and the toe-in may change slightly when
under load.

I think it boils down to what wins when you start to go into a turn
with a taildragger- does the toed-in outside wheel "drag" and thus
want to straighten you back out or does the toed-out outside wheel get
weight transferred to it and tend to straighten you out (vs tightening
the turn)?

Anybody with some definite answers based on physics? There's lots of
emperical and experiential opinions out there, anybody with some more
factual answers to the argument?

J oa

Toe in vs Toe out depends on the type of gear you have your wheels
connected to. This is the absolute first thing to consider before even
thinking about setting toe. If your gear is articulated you
need neutral or toe-in. Why? Because the gear legs will be forced apart
with toe out and the plane will start to sink on its gear. And it will
happen as you push it out of the hanger. It takes very little to get the
gear legs to spread if there is toe out. The rate at which it will sink
depends on the amount of toe out. So if you have bungees or
springs on some sort of A arm gear legs please don't use any toe-out.


If you have fixed gear like a one piece steel or aluminum unit then you
can consider all these other posts about how it should be set.

Mike

On Fri, 28 Nov 2003 17:21:21 GMT, Mr Nobody
wrote:

J oa

Toe in vs Toe out depends on the type of gear you have your wheels
connected to. This is the absolute first thing to consider before even
thinking about setting toe. If your gear is articulated you
need neutral or toe-in. Why? Because the gear legs will be forced apart
with toe out and the plane will start to sink on its gear. And it will
happen as you push it out of the hanger. It takes very little to get the
gear legs to spread if there is toe out. The rate at which it will sink
depends on the amount of toe out. So if you have bungees or
springs on some sort of A arm gear legs please don't use any toe-out.


I'll take issue here.
Your plane is so light the wheels will "scuff" long before they squat
the suspension enough to affect anything. Particularly when talking
only a few degrees of toe-out.
Now, if you were putting thousands of miles on the plane on the ground
tire wear would possibly become an issue, but you FLY the thing.
If you have fixed gear like a one piece steel or aluminum unit then you
can consider all these other posts about how it should be set.

Mike

One other thing to consider (and I can't help but wonder if it makes a greater
difference than initial toe in or out setting) is the angle (camber) of the
tire as it sits on the ground. The camber obviously changes with the weight on
the gear at any time. The problem is the bias ply tires that are on light
aircraft. They normally tend to want to steer toward the way they are leaning
as slight as that may be. Inflation could also effect this tendency.

Jim