Some tailwheel questions/comments

wrote in
ups.com:



Not really, and I'd be surprised if you could taxi a Citabria with
the tailwheel raised anyway. Easy in a cub, though.


Firstly this isnt a troll and if somebody feels it is, they simply
need to ignore it, thats how usenet works. Anyways, the question was
based more on what I saw on the takeoff run where we raise the tail as
airspeed increases. It just felt more stable and more like a
conventional gear takeoff run in that phase, so I was just wondering.
The intent of the question wasn't about how to taxi at a high speed.

Ah, OK. Wel, the main reason you get the tail up is to aid acceleration
and to have th eairplane in the correct atttude when you rotate.
You have a lot of power on and that is why the airplane feels more
stable than when you are taxiing. The reason being the vast amount of
air yu have going over the rudder.
Not all airplanes re like that, BTW. Some get very interesting when you
raise the tail on takeoff!

The problem with the Citabria is it's a bit too easy for tailwheel
conversion. You'll get the basics, but if you try a cub afterwards
you'll find it significantly more difficult, wheras the other way
around would be a piece of cake. Citabria is a good airplane, but
it's not the best tailwheel trainer for that reason. However, it will
certainly do in a pinch!

Thanks for the tip, I have been looking to find a place to learn in a
cub but the closest one is about 70 miles away, so that may have to
wait.

Nothing wrong with a Citabria, but the cub is just so perfect. You'll
learn a lot in a Citabira as well, Just be aware that when you get the
tailwheel signoff you're not "there" In fact it doesn't matter what
you've been checked out in, you're only just like a kid who's been let
go onhis first two wheeler..

The CG doesn't change significantly when the tail is raised, though,
to
answer your question, and fast taxiing is something best left to
someone with a LOT of tailwhel time. Taxiing on the mains is
something best left to airshow pilots or guys that can afford to
replace props as easily as they would buy a cup of coffee.

What my instructor seemed to imply (and things didn't really sink in
till about a day after the flying) was that the takeoff roll is more
stable when the tail is up. So I was wondering if the CG shifts
forward when the tail is raised because this is a more stable
configuration than when the CG is behind the main wheels.


Ah, OK. Well, it might have something to do with that, but I'd suspect
it;s more to do with decreasing the angle of attack on the wings.


Bertie

"Bertie the Bunyip" wrote

One piece of advice I can give that's useful to new talidragger pilots,
or at least I've found it so, is to get religious about aving the
controls in the right position when taxiing in wind. Any wind at all.
Even three knots. For one thing, having the ailerons in particualr,
plcaed correctly, you increase your control of the airplane
dramatically. Being in the habit of doing this wil give you the edge you
need it during crosswind landings. It's habits that come to the
forefront when your brain degenerates to it's primevel state when things
start happening quickly.

Good advice. It's easy to get complacent about control positioning while
taxiing, and I know what you mean about the difference in control when
they're in the right position. You can definitely feel the difference.

BTW, when taxiing with a tailwind you need to reverse, as yo know. Don't
forget to consider the taxi speed of your airplane in relation to the
wind. Elevators are tricky in this situation. If you got a roaring
tailwind, you need to have them forward (Careful with the power here or
you could have an instant headwind as far as your elevators are
concerned) It can be hard to tell if you need the elevators up or down
when you're taxing downwind, but th erule I use is if you can feel the
stick "click" as the wind passes ovr the elavotrs as you move them up
and down you should have them down. Make sense?

I'll have to try that rule of thumb next time but it sounds like what you're
saying is that if you can feel the wind pushing on the elevator as it moves
through neutral then it should be down. I've been taxiing with the elevator
full forward in all tailwind conditions up to this point, and that's
probably not a good habit to get into, especially when moving into something
with more power.

BDS

Our guy on the field had zero hours, but then bought a new SR-22. Rumor had
it was that he did a lot of flying IFR without the rating, and he would
routinely fly over Lake Michigan in IMC in the single.

His take off routine was to rotate, pick up some speed, and then do a high g
pull-up. We called him "super pull up" on the field.

He then bought an SU-29, with absolutely no tailwheel time. He got signed
off in less than 7 hours as being good to go (yeah, right), and on his first
couple of flights he dropped it in from a height, requiring a new prop, and
major structural repairs.

To his credit, he took a lot more lessons, and appears to be flying a lot
more conservatively and safely since his experience.

Of course, some people never make a mistake, so this wouldn't apply to them.

On Sep 25, 8:05 am, Bertie the Bunyip wrote:
Little Endian wrote in news:1190700037.145345.27050
@y42g2000hsy.googlegroups.com:

This weekend I began my tailwheel endorsement endeavor and had a
lesson in a shiny 160 hp Citabria. It was great fun but the stick and
rudder forces seemed pretty heavy compared to the C-150 I am used to.
The trim was in an unfamiliar position and I didn't get used to using
it enough on the first flight perhaps. However are there tailwheels
that are lighter to handle than the citabria?
The other issue I was wondering about: does the position of the CG
shift when the tail is raised? So is the tailwheel more stable while
taxing at a higher speed on the two front wheels? In other words, I am
wondering if a tailwheel taxing with the tail raised has a similar CG
position to a tricycle gear airplane.

Not really, and I'd be surprised if you could taxi a Citabria with the
tailwheel raised anyway. Easy in a cub, though.

The problem with the Citabria is it's a bit too easy for tailwheel
conversion. You'll get the basics, but if you try a cub afterwards you'll
find it significantly more difficult, wheras the other way around would be
a piece of cake. Citabria is a good airplane, but it's not the best
tailwheel trainer for that reason. However, it will certainly do in a
pinch!
The CG doesn't change significantly when the tail is raised, though, to
answer your question, and fast taxiing is something best left to someone
with a LOT of tailwhel time. Taxiing on the mains is something best left to
airshow pilots or guys that can afford to replace props as easily as they
would buy a cup of coffee.
Now ask me how I know this.

Bertie

It's not that hard at all. I've taxied down the runway on one main.
I've taught students that if they're having trouble waking their feet
up or can't seem to get the cross-control set up for a crosswind. I've
brought both the Citabria and 185 pretty much to a halt with the
brakes before setting the tail down. I've done tail-high/nose-low
braking, using a tiny bit of power for elevator authority, to get
weight on the mains and stop really short. You have to realize that
you are flying a taildragger ALL the time, not just when it's in the
air.
I invented a term years ago to describe the disease suffered by
trike pilots: Somnopedosis. Means "sleepy feet."

Dan

On Tue, 25 Sep 2007 10:37:03 -0400, "BDS" wrote:

I plan to transition to a Husky (180 HP CS prop), any comments about what to
expect, relative difficulty, etc?

The Husky is a big, heavy airplane. (Husky, in fact!) It is nothing
like a Cub--not much like a Super Cub either.

It is much easier to land a Husky than a J-3. You can put the nose up
a bit and put on a bit of power, and lower yourself down as if you
were on a string. Try that in a J-3 and it will simply keep on flying.

The thing I really remember about flying a Husky is that I kept
skinning my knuckles on the trim wheel. I was bleeding all the time.

I never flew the Husky solo. I was on a "mountain flying" course with
Damian Delgaizo in Andover NJ. It's a lot easier to do something when
you have a skilled pilot backing you up.

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
new from HarperCollins www.FlyingTigersBook.com

On Tue, 25 Sep 2007 10:39:37 -0700, wrote:

What my instructor seemed to imply (and things didn't really sink in
till about a day after the flying) was that the takeoff roll is more
stable when the tail is up. So I was wondering if the CG shifts
forward when the tail is raised because this is a more stable
configuration than when the CG is behind the main wheels.

It's still aft of the mains!

I get the tailwheel off the ground as soon as the Cub begins to roll.
You don't want to do a takeoff roll flat on the asphalt, though, or
even on the grass. The plane will pound. Have the tail enough below
parallel that some of the weight of the plane is carried by the wings.

(I never really thought about this before, so excuse me if the wording
is awkward.)


Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
new from HarperCollins www.FlyingTigersBook.com

This is basic piloting 101.
Have you calculated the takeoff CG?
What can you do to make the CG change?
How is what you described above going to influence the CG location on
takeoff or landing?
Answer those questions and you will have answered your own.

The airplane is not a rigid body from a physics point of view, so the
CG can change, maybe not by much but I dont know enough about the
tailwheel to know if it moves just a little bit forward which may be
all it takes to make it "more" stable. Basic 101 piloting may not
always be enough to answer every question.

Little Endian wrote:
does the position of the CG shift when the tail is raised?

S'cuse me but perhaps I am confused but once everything is lashed down in yer
plane, ain't the CG static in relation to the airframe. Unless you lean
yourself waaaay forward in your seat. but even that's not gonna make that
much difference.

I suspect it may appear to move in some frame of reference but I'm thinking
all that matters is structural CG relation to MAC or CP...no?

In other words, I am wondering if a tailwheel taxing with the tail raised has a similar CG
position to a tricycle gear airplane.

And we know that cg is behind the mains on a t-dragger and in front for
trikes.

--
Message posted via http://www.aviationkb.com

On 25 Sep, 19:22, "Viperdoc" wrote:
Our guy on the field had zero hours, but then bought a new SR-22. Rumor had
it was that he did a lot of flying IFR without the rating, and he would
routinely fly over Lake Michigan in IMC in the single.

His take off routine was to rotate, pick up some speed, and then do a high g
pull-up. We called him "super pull up" on the field.

He then bought an SU-29, with absolutely no tailwheel time. He got signed
off in less than 7 hours as being good to go (yeah, right), and on his first
couple of flights he dropped it in from a height, requiring a new prop, and
major structural repairs.

To his credit, he took a lot more lessons, and appears to be flying a lot
more conservatively and safely since his experience.

Of course, some people never make a mistake, so this wouldn't apply to them.

Well, people that don't fly, obviously..


Bertie

On 25 Sep, 19:03, "BDS" wrote:
"Bertie the Bunyip" wrote

One piece of advice I can give that's useful to new talidragger pilots,
or at least I've found it so, is to get religious about aving the
controls in the right position when taxiing in wind. Any wind at all.
Even three knots. For one thing, having the ailerons in particualr,
plcaed correctly, you increase your control of the airplane
dramatically. Being in the habit of doing this wil give you the edge you
need it during crosswind landings. It's habits that come to the
forefront when your brain degenerates to it's primevel state when things
start happening quickly.

Good advice. It's easy to get complacent about control positioning while
taxiing, and I know what you mean about the difference in control when
they're in the right position. You can definitely feel the difference.

BTW, when taxiing with a tailwind you need to reverse, as yo know. Don't
forget to consider the taxi speed of your airplane in relation to the
wind. Elevators are tricky in this situation. If you got a roaring
tailwind, you need to have them forward (Careful with the power here or
you could have an instant headwind as far as your elevators are
concerned) It can be hard to tell if you need the elevators up or down
when you're taxing downwind, but th erule I use is if you can feel the
stick "click" as the wind passes ovr the elavotrs as you move them up
and down you should have them down. Make sense?

I'll have to try that rule of thumb next time but it sounds like what you're
saying is that if you can feel the wind pushing on the elevator as it moves
through neutral then it should be down. I've been taxiing with the elevator
full forward in all tailwind conditions up to this point, and that's
probably not a good habit to get into, especially when moving into something
with more power.

BDS

Yes, sounds like you got the idea. An awful lot of airplanes end up on
their nose (particularly Supercubs for some reason) because the pilot
turns downwind quickley using a bit of brake at the same time.

Bertie