David, I don't think were are comparing apples to apples in our discussion
of this reflexor issue, but here are my comments as a flyer, not as a
designer.

Original Message <<<<<<<<<<<<<<<<<<

On 5/21/03, 1:33:11 PM, "Larry Koutz" <koutzl@...> wrote
regarding Re: [Q-LIST] Re: Reflexor:

COBRA is from Mig-29. Is good front line fighter from old country.

Sergei

had flameout in Mig-29 in middle of COBRA at Paris airshow> :-)

What exactly did the Mig-29 do and does COBRA stand for anything?
Usually if you have enough energy and have a flame out you would try a
restart as you zoom up. If the engine doesn't respond; it is bail out

time!

That is what I understand Sergei (or whatever his name is) actually did.
He turned it vertical, caused a compressor stall, executed the restart
proceedure (while ascending and decellerating, vertically), was
unsuccessful at the restart, initialed a tail-slide, ejected
horizontally, chute opened with ~100 feet to spare. Plane decended
vertically, exploded, and when the rescue team got to Sergei, he was
standing, flight helmet under his arm, smoking a cigarette. Story may
have been embellished, but that's how I heard it. I remember seeing it
on film.

Jay

Larry Koutz wrote:

Pulling the nose up before TO is what you do on all tricycle
airplanes. You
apply back pressure to the stick, the nose rises to a certain attitude and
you hold it there with the stick. When the speed is right the
airplane lifts
off. Happens all the time. So does aero braking on planes.
Problem is in the Q-XX with down elevator there is an awful lot
of drag with
the elevator deflected. In addition to that, to actually get the nose to
rise most pilots will pull in more back pressure than needed then suddenly
the nose will rise and overshoot takeoff attitude and may lift off early,
but anyway it IS the start of the COBRA maneuver and I know -that IS
certainly dangerous.

Well, the conventional airplane has the tail in back, so when it rotates the
tail becomes less effective at pulling the tail down/nose up. This is a
natural limiting effect that is absent from the Tri-Q, and all those other
tri-geared canard airplanes. Ask any Long-EZE flyer; you have to let off on
the back pressure once you rotate. The only problem I'm concerned with in
this discussion is the fact that on SOME Tri-Qs, this can't happen until the
airplane is well past what should have been liftoff speed. On these planes,
someone has advocated using the reflexor to "help" get the nose up, and I
think that is a dangerous use of the reflexor and that there is a better
solution to be had in fixing the landing gear geometry.

With the elevator deflected the canard is trying to created MORE lift than
it was designed to lift. With the ailerons reflexed UP the main
wing is less
likely to stall at the same angle of attack No matter what you
say the plane
will not lift off and actually fly unless each lifting surface
provides the
exact amount lift required and the plane doesn't care if the
elevator is up,
down or flushed in or the ailerons are both up, down or flushed in.

"Flaps," whether we call them aileron, elevator, reflexor, or flap, are all
the same: trailing-edge devices that change the camber of the wing. Flaps
are most commonly known as "high-lift" devices. When you extend the flaps,
you increase the maximum available coefficient of lift (Cl_max); when you
retract the flaps, you decrease the Cl_max; and when you "reflex" the flaps,
you decrease the Cl_max even more. Look it up.

Therefore, when you take off with the reflexor TE-up, the Cl_max of the main
wing is less than it was with the reflexor at neutral. Therefore, in order
to make whatever Cl is needed to get the airplane off the ground at that
moment, you'll be lifting off with a smaller margin above the stall for that
main wing. Additionally, since the elevator does not have to be extended so
far now due to the reflexor "helping" to rotate the plane, you have more
additional elevator available with which to further rotate the airplane than
if you were taking off with the reflexor neutral.

So, you're right, the airplane will not lift off and actually fly unless
each lifting surface provides the exact amount of lift required, and the
plane doesn't care about the control surface positions. BUT, you'll be
operating with the main wing closer to stall AOA and you'll have a VERY
effective elevator control available to help you accidentally over-rotate
and put you into a main wing stall. Or maybe just a little gust will come
along and start that main wing stall for you. Once the back end drops out,
look out, buddy!!

I'm not saying that WILL happen, I am saying it MIGHT happen, because we
don't know what the margin is, and because not everybody has the same
reflexor position stops, and on and on. I'm only advocating CAUTION in using
TE-up reflexor, and I AM saying that there's a better solution than using
the reflexor to address the problem of airplanes that won't rotate for
takeoff in a timely manner.

I know of only one person that had this happen and his ailerons were
reflexed DOWN and he was correcting for a roll on final. He put in aileron
to correct and the plane rolled the opposite way!

Well, a documented aileron stall! Now we know why the reflexor should not be
allowed to go TE-down...! That's also a good indication of how heavily
loaded the main wing is at low airspeeds, as per our analysis the other day.
If it can do this with MORE margin above stall AOA (due to TE-down reflexor)
then think how close to stall that main wing might be when you use TE-up
reflexor.

People are using it for this purpose -successfully. I recommend it for
landing, trimming, cruise control.

All good uses for a reflexor. Just please don't use it to "help" rotate for
takeoff.

for takeoff, set it like a trim setting in any other airplane, that is, set
it for the approximate trim setting that you will need on initial climb-out
after liftoff. In other words, don't use "extra" nose-up reflexor to "help"
get the nose up.

If you find yourself needing to do something to get the airplane to rotate
for liftoff, don't succumb to the temptation to use excess reflexor but
adjust your static ground attitude, instead.

That is RIGHT. I have experience and I know reflexors are effective. And
they also CORRECTED a badly built airplane and made it flyable.
The ultimate
solution was to CORRECT the flying surface angle of incidence.

They didn't "correct" that badly-built plane, they only made it possible to
fly it so that you could sort out the real problem of incorrect flying
surface angles of incidence. You said it yourself: "The ultimate solution
was to CORRECT the flying surface angle of incidence;" likewise, the
ultimate solution to fixing the late-rotation problem is to adjust the
landing gear to give a better ground attitude.

Sure, you can get the airplane to fly using the reflexor to make it rotate,
but I say that this is not to be construed as a desirable standard
operation, only a useful tool to help you diagnose the airplane's
deficiencies during its flight test period. Tho objective of the flight test
period, of course, is to correct such deficiencies, as you finally got
around to correcting your flying surface incidence angle deficiencies and
stopped flying around with the reflexor up -- what -- 45 degrees? All I'm
saying is that taking off with the "trim" (reflexor ) set to full "up" in
order to get the nosewheel off the ground and then having to re-trim for
climb is unnatural and potentially unsafe, and that there is an "ultimate
solution" in establishing a correct static ground attitude.

I do NOT know that the stall speed is effected at ALL by the
reflexors, only
the attitude of the plane. I have tested this in flight in my
airplane and I
find no significant stall speed change, just attitude. Near the
ground this
may be different but I don't have a long stretch of the Great Salt Lake to
test the effects down low.

I wouldn't expect the stall speed to be significantly changed unless the
reflexor were significantly deflected, but I thought I recalled you saying
at one time that you had observed something. My bad. Apparently I'm wrong.
However, I can think of several reasons to expect the stall speed to change
with different positions of the reflexor, not the least being that TE-up
reflexor allows the elevator to be "retracted" like a retracted flap instead
of extended (deflected TE-down) like an extended flap. And we all know that
wings with extended flaps (TE-down elevator) have lower stalling speeds than
wings with their flaps retracted (elevator more "neutral") as would be
observed with the reflexor TE-up. I don't suppose that ground effect would
make much difference.

I have never had an aft wing stall, that I know of.

I'm just trying to keep it that way. Say, you're not driving a Tri-Q on a
regular basis, anyway! Your plane is a taildragger, and I don't expect that
you make a habit of taking off with the reflexor "trim" set anywhere other
than approximately right for climbout, do you?

The reflexor is NOT a band-aid for nosedraggers, it never was. It WAS a
band-aid for squirreley taildraggers, that proved to be useful for

inflight

trimming, too.

I don't know that many Tri-qers would support that assertion. I would
certainly want a reflexor if I had a Tri-Q.

Hmmmm, I didn't say the reflexor was not appropriate for Tri-Qs, but
apparently you and Lynn French both took it that way. Sorry, that's not what
I meant. What I meant was that the reflexor was initially developed for the
taildragger (Tri-Qs hadn't been invented at that point), and that the
development of the reflexor was initially in response to the taildragger's
perceived lack of tailwheel authority. It has since proved useful in more
ways and is now widely regarded as a necessity for all Q-2xx's, for which I
agree! That doesn't negate its potential for harm if used incorrectly,
either.

Now it seems that some advocate its use as everything, to the
point of suggesting that it be geared into the control stick or used in
place of the front-wing elevators. ARRGH!

Who has said this- might be worth a try!

Hey, Rutan effectively did it on the Ams/Oil racer when he geared the T-tail
to the control stick. It worked for them, but we don't have the benefit of
their expertise. Anyhow, I bet they had a separate trim system and that they
didn't take off with the trim set to full up with the intention of suddenly
re-trimming as soon as they broke ground.

The current discussion centers around the suggestion to use the reflexor

to

"fix" a tri-Q that won't rotate for takeoff.

This is not a "fix", just a technique I used to get a "new 70 something
pilot wanta be" to see that his plane (a Tri-DFly) needs to be
rotated to a
certain attitude and held there until the plane is ready to fly off. He
couldn't handle the quick nose rotation at about takeoff speed. I also
showed him the effectiveness of the reflexor.

Okay, apples and oranges? I'm trying to discuss apples (Tri-Qs that won't
rotate for takeoff) and you're talking oranges (a teaching demonstration in
an airplane that presumably did not "need" extra help rotating for liftoff).

I stand on my conviction that the CORRECT solution to this problem is to

either lengthen the nose gear or

shorten the main gear (or both) and, maybe, move the main gear forward.

How come regular tri geared plane designers don't use this design
technique.

They don't have to! They generally aren't elevator limited like canards are.
The conventional airplane's stabilizer/elevator is most effective at lifting
the nose when it is at its most negative angle (nose down), and it loses
authority as the airplane rotates nose up. The canard's stabilizer/elevator
(canard) is at its LEAST effective for lifting the nose when the airplane is
nose down, and it becomes MORE effective as the airplane rotates nose up.
Hence my assertion from the get-go of this whole discussion that the correct
fix for an airplane that rotates late is to make the airplane sit more
nose-up by altering the landing gear. A more nose-up stance will make the
canard/elevator initially more effective at lifting the nose and allow the
nose to be lifted at a lower speed/sooner during the takeoff roll.

That is why we are supposed to test each new airplane, because
each plane IS
unique, even though they are similar.

Yessir!

I believe that a properly set up Tri-Q should be able to high-speed taxi

on

the main gear using elevator alone. It will probably not be able to

initiate

nose-wheel liftoff as early in the takeoff run as a

conventional airplane,

but a positive rotation to takeoff attitude should be available

well below

actual liftoff speed. This is a simple result of the fact that the main

gear

is ahead of the main wing.

That IS my point exactly! A "properly set up" Tri-Q may not need
a reflexor,
but a "new plane" certainly might and they aren't that hard to put in. I
think flyers of these planes would put them in again- you might consider a
reflexor too!

Ummm, I am not advocating getting rid of reflexors or not having them, just
not over-USING them for stuff that is better addressed in other ways. Sure,
in a new plane you can take the test-pilot risk (if you know what you're
looking for) and use the reflexor to make up for a deficiency long enough to
diagnose and correct that deficiency. Just let's not make the temporary use
into a standard operating procedure and ignore the opportunity to actually
correct the inadequacy.


David J. Gall
I'm tired, so I'm not proof-reading tonight. Any errors are the fault of my
computer not being smart enough to know what I'm trying to say wighout me
acutally hvaing to yas ti. :-)

On my second take off in my Tri-Q I made the mistake of having the refexor all the way down. The airplane would not lift off. I had to use alot of back pressure on the stick to lift it off, which I should have not done. After lift off while holding some serous back pressure to try to keep it flying I cut the power and came back down with a few bounces. I learned a lesson though. Part of the Pre takeoff check list is reflexor up. In my plane the reflexor down is even with the wing, and deflects 3 or 4 degrees when all the way up. Where the reflexor is set in cruise depends on how heavy the plane is loaded. With a light load the refexor is set more in the upper half of the trave, the heavier it is loaded the more down I need to set it. I would like to hear what some other Q's relexor travel is, and where they set it for take off and in cruise conditons. Kelly

From: "David J. Gall" <David@...>
Reply-To: Q-LIST@...
To: <Q-LIST@...>
Subject: RE: [Q-LIST] Re: Reflexor
Date: Thu, 22 May 2003 00:45:26 -0400

Larry Koutz wrote:

Pulling the nose up before TO is what you do on all tricycle
airplanes. You
apply back pressure to the stick, the nose rises to a certain attitude

and

you hold it there with the stick. When the speed is right the
airplane lifts
off. Happens all the time. So does aero braking on planes.
Problem is in the Q-XX with down elevator there is an awful lot
of drag with
the elevator deflected. In addition to that, to actually get the nose to
rise most pilots will pull in more back pressure than needed then

suddenly

the nose will rise and overshoot takeoff attitude and may lift off

early,

but anyway it IS the start of the COBRA maneuver and I know -that IS
certainly dangerous.

Well, the conventional airplane has the tail in back, so when it rotates the
tail becomes less effective at pulling the tail down/nose up. This is a
natural limiting effect that is absent from the Tri-Q, and all those other
tri-geared canard airplanes. Ask any Long-EZE flyer; you have to let off on
the back pressure once you rotate. The only problem I'm concerned with in
this discussion is the fact that on SOME Tri-Qs, this can't happen until the
airplane is well past what should have been liftoff speed. On these planes,
someone has advocated using the reflexor to "help" get the nose up, and I
think that is a dangerous use of the reflexor and that there is a better
solution to be had in fixing the landing gear geometry.

With the elevator deflected the canard is trying to created MORE lift

than

it was designed to lift. With the ailerons reflexed UP the main
wing is less
likely to stall at the same angle of attack No matter what you
say the plane
will not lift off and actually fly unless each lifting surface
provides the
exact amount lift required and the plane doesn't care if the
elevator is up,
down or flushed in or the ailerons are both up, down or flushed in.

"Flaps," whether we call them aileron, elevator, reflexor, or flap, are all
the same: trailing-edge devices that change the camber of the wing. Flaps
are most commonly known as "high-lift" devices. When you extend the flaps,
you increase the maximum available coefficient of lift (Cl_max); when you
retract the flaps, you decrease the Cl_max; and when you "reflex" the flaps,
you decrease the Cl_max even more. Look it up.

Therefore, when you take off with the reflexor TE-up, the Cl_max of the main
wing is less than it was with the reflexor at neutral. Therefore, in order
to make whatever Cl is needed to get the airplane off the ground at that
moment, you'll be lifting off with a smaller margin above the stall for that
main wing. Additionally, since the elevator does not have to be extended so
far now due to the reflexor "helping" to rotate the plane, you have more
additional elevator available with which to further rotate the airplane than
if you were taking off with the reflexor neutral.

So, you're right, the airplane will not lift off and actually fly unless
each lifting surface provides the exact amount of lift required, and the
plane doesn't care about the control surface positions. BUT, you'll be
operating with the main wing closer to stall AOA and you'll have a VERY
effective elevator control available to help you accidentally over-rotate
and put you into a main wing stall. Or maybe just a little gust will come
along and start that main wing stall for you. Once the back end drops out,
look out, buddy!!

I'm not saying that WILL happen, I am saying it MIGHT happen, because we
don't know what the margin is, and because not everybody has the same
reflexor position stops, and on and on. I'm only advocating CAUTION in using
TE-up reflexor, and I AM saying that there's a better solution than using
the reflexor to address the problem of airplanes that won't rotate for
takeoff in a timely manner.

I know of only one person that had this happen and his ailerons were
reflexed DOWN and he was correcting for a roll on final. He put in

aileron

to correct and the plane rolled the opposite way!

Well, a documented aileron stall! Now we know why the reflexor should not be
allowed to go TE-down...! That's also a good indication of how heavily
loaded the main wing is at low airspeeds, as per our analysis the other day.
If it can do this with MORE margin above stall AOA (due to TE-down reflexor)
then think how close to stall that main wing might be when you use TE-up
reflexor.

People are using it for this purpose -successfully. I recommend it for
landing, trimming, cruise control.

All good uses for a reflexor. Just please don't use it to "help" rotate for
takeoff.

for takeoff, set it like a trim setting in any other airplane, that is, set
it for the approximate trim setting that you will need on initial climb-out
after liftoff. In other words, don't use "extra" nose-up reflexor to "help"
get the nose up.

If you find yourself needing to do something to get the airplane to rotate
for liftoff, don't succumb to the temptation to use excess reflexor but
adjust your static ground attitude, instead.

That is RIGHT. I have experience and I know reflexors are effective. And
they also CORRECTED a badly built airplane and made it flyable.
The ultimate
solution was to CORRECT the flying surface angle of incidence.

They didn't "correct" that badly-built plane, they only made it possible to
fly it so that you could sort out the real problem of incorrect flying
surface angles of incidence. You said it yourself: "The ultimate solution
was to CORRECT the flying surface angle of incidence;" likewise, the
ultimate solution to fixing the late-rotation problem is to adjust the
landing gear to give a better ground attitude.

Sure, you can get the airplane to fly using the reflexor to make it rotate,
but I say that this is not to be construed as a desirable standard
operation, only a useful tool to help you diagnose the airplane's
deficiencies during its flight test period. Tho objective of the flight test
period, of course, is to correct such deficiencies, as you finally got
around to correcting your flying surface incidence angle deficiencies and
stopped flying around with the reflexor up -- what -- 45 degrees? All I'm
saying is that taking off with the "trim" (reflexor ) set to full "up" in
order to get the nosewheel off the ground and then having to re-trim for
climb is unnatural and potentially unsafe, and that there is an "ultimate
solution" in establishing a correct static ground attitude.

I do NOT know that the stall speed is effected at ALL by the
reflexors, only
the attitude of the plane. I have tested this in flight in my
airplane and I
find no significant stall speed change, just attitude. Near the
ground this
may be different but I don't have a long stretch of the Great Salt Lake

to

test the effects down low.

I wouldn't expect the stall speed to be significantly changed unless the
reflexor were significantly deflected, but I thought I recalled you saying
at one time that you had observed something. My bad. Apparently I'm wrong.
However, I can think of several reasons to expect the stall speed to change
with different positions of the reflexor, not the least being that TE-up
reflexor allows the elevator to be "retracted" like a retracted flap instead
of extended (deflected TE-down) like an extended flap. And we all know that
wings with extended flaps (TE-down elevator) have lower stalling speeds than
wings with their flaps retracted (elevator more "neutral") as would be
observed with the reflexor TE-up. I don't suppose that ground effect would
make much difference.

I have never had an aft wing stall, that I know of.

I'm just trying to keep it that way. Say, you're not driving a Tri-Q on a
regular basis, anyway! Your plane is a taildragger, and I don't expect that
you make a habit of taking off with the reflexor "trim" set anywhere other
than approximately right for climbout, do you?

The reflexor is NOT a band-aid for nosedraggers, it never was. It WAS

a

band-aid for squirreley taildraggers, that proved to be useful for

inflight

trimming, too.

I don't know that many Tri-qers would support that assertion. I would
certainly want a reflexor if I had a Tri-Q.

Hmmmm, I didn't say the reflexor was not appropriate for Tri-Qs, but
apparently you and Lynn French both took it that way. Sorry, that's not what
I meant. What I meant was that the reflexor was initially developed for the
taildragger (Tri-Qs hadn't been invented at that point), and that the
development of the reflexor was initially in response to the taildragger's
perceived lack of tailwheel authority. It has since proved useful in more
ways and is now widely regarded as a necessity for all Q-2xx's, for which I
agree! That doesn't negate its potential for harm if used incorrectly,
either.

Now it seems that some advocate its use as everything, to the
point of suggesting that it be geared into the control stick or used

in

place of the front-wing elevators. ARRGH!

Who has said this- might be worth a try!

Hey, Rutan effectively did it on the Ams/Oil racer when he geared the T-tail
to the control stick. It worked for them, but we don't have the benefit of
their expertise. Anyhow, I bet they had a separate trim system and that they
didn't take off with the trim set to full up with the intention of suddenly
re-trimming as soon as they broke ground.

The current discussion centers around the suggestion to use the

reflexor

to

"fix" a tri-Q that won't rotate for takeoff.

This is not a "fix", just a technique I used to get a "new 70 something
pilot wanta be" to see that his plane (a Tri-DFly) needs to be
rotated to a
certain attitude and held there until the plane is ready to fly off. He
couldn't handle the quick nose rotation at about takeoff speed. I also
showed him the effectiveness of the reflexor.

Okay, apples and oranges? I'm trying to discuss apples (Tri-Qs that won't
rotate for takeoff) and you're talking oranges (a teaching demonstration in
an airplane that presumably did not "need" extra help rotating for liftoff).

I stand on my conviction that the CORRECT solution to this problem is

to

either lengthen the nose gear or

shorten the main gear (or both) and, maybe, move the main gear

forward.

How come regular tri geared plane designers don't use this design
technique.

They don't have to! They generally aren't elevator limited like canards are.
The conventional airplane's stabilizer/elevator is most effective at lifting
the nose when it is at its most negative angle (nose down), and it loses
authority as the airplane rotates nose up. The canard's stabilizer/elevator
(canard) is at its LEAST effective for lifting the nose when the airplane is
nose down, and it becomes MORE effective as the airplane rotates nose up.
Hence my assertion from the get-go of this whole discussion that the correct
fix for an airplane that rotates late is to make the airplane sit more
nose-up by altering the landing gear. A more nose-up stance will make the
canard/elevator initially more effective at lifting the nose and allow the
nose to be lifted at a lower speed/sooner during the takeoff roll.

That is why we are supposed to test each new airplane, because
each plane IS
unique, even though they are similar.

Yessir!

I believe that a properly set up Tri-Q should be able to high-speed

taxi

on

the main gear using elevator alone. It will probably not be able to

initiate

nose-wheel liftoff as early in the takeoff run as a

conventional airplane,

but a positive rotation to takeoff attitude should be available

well below

actual liftoff speed. This is a simple result of the fact that the

main

gear

is ahead of the main wing.

That IS my point exactly! A "properly set up" Tri-Q may not need
a reflexor,
but a "new plane" certainly might and they aren't that hard to put in. I
think flyers of these planes would put them in again- you might consider

a

reflexor too!

Ummm, I am not advocating getting rid of reflexors or not having them, just
not over-USING them for stuff that is better addressed in other ways. Sure,
in a new plane you can take the test-pilot risk (if you know what you're
looking for) and use the reflexor to make up for a deficiency long enough to
diagnose and correct that deficiency. Just let's not make the temporary use
into a standard operating procedure and ignore the opportunity to actually
correct the inadequacy.


David J. Gall
I'm tired, so I'm not proof-reading tonight. Any errors are the fault of my
computer not being smart enough to know what I'm trying to say wighout me
acutally hvaing to yas ti. :-)

_________________________________________________________________
The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail

I have the MAC servor. I set it 1.5 bars up for takeoff and initial
climbout 85-90mph. cruise it is .5 bars up. Landing it is 3.5 bars up
(sorry about that D. Gall)
Jerry

Kelly Poor wrote:

On my second take off in my Tri-Q I made the mistake of having the refexor
all the way down. The airplane would not lift off.

<snip>

In my
plane the reflexor down is even with the wing, and deflects 3 or 4 degrees
when all the way up.

Let me see if I have this right.

With your reflexor lever in the "down" position, your ailerons are
actually in trail (not down at all) and the plane can't rotate?

Pat

It can rotate, I did lift it off but had to use alot of back pressue on the stick to do it. Kelly

From: Patrick Panzera <panzera@...>
Reply-To: Q-LIST@...
To: Q-LIST@...
Subject: Re: [Q-LIST] Re: Reflexor
Date: Thu, 22 May 2003 07:24:03 -0700


Kelly Poor wrote:

On my second take off in my Tri-Q I made the mistake of having the

refexor

all the way down. The airplane would not lift off.

<snip>

In my
plane the reflexor down is even with the wing, and deflects 3 or 4

degrees

when all the way up.

Let me see if I have this right.

With your reflexor lever in the "down" position, your ailerons are
actually in trail (not down at all) and the plane can't rotate?

Pat

_________________________________________________________________
STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail

Jerry,

What do bars amount to in inches?

Ryan


--- In Q-LIST@..., "jnmarstall" <jnmarstall@b...> wrote:

I have the MAC servor. I set it 1.5 bars up for takeoff and initial
climbout 85-90mph. cruise it is .5 bars up. Landing it is 3.5

bars up

(sorry about that D. Gall)
Jerry

Hi Kelly

Does this not indicate that you could do with more canard incidence?
Do you have any canard incidence or was the water line set level?
When in cruise do you set it in order to 'fair in' the elevators (zero deflection)?

Paul Buckley
Cheshire, England
Tri Q-200
90% finished,..90% to go!
Original Message -----
From: Kelly Poor
To: Q-LIST@...
Sent: Thursday, May 22, 2003 2:37 PM
Subject: RE: [Q-LIST] Re: Reflexor


On my second take off in my Tri-Q I made the mistake of having the refexor
all the way down. The airplane would not lift off. I had to use alot of
back pressure on the stick to lift it off, which I should have not done.
After lift off while holding some serous back pressure to try to keep it
flying I cut the power and came back down with a few bounces. I learned a
lesson though. Part of the Pre takeoff check list is reflexor up. In my
plane the reflexor down is even with the wing, and deflects 3 or 4 degrees
when all the way up. Where the reflexor is set in cruise depends on how
heavy the plane is loaded. With a light load the refexor is set more in the
upper half of the trave, the heavier it is loaded the more down I need to
set it. I would like to hear what some other Q's relexor travel is, and
where they set it for take off and in cruise conditons. Kelly


>From: "David J. Gall" <David@...>
>Reply-To: Q-LIST@...
>To: <Q-LIST@...>
>Subject: RE: [Q-LIST] Re: Reflexor
>Date: Thu, 22 May 2003 00:45:26 -0400
>
>Larry Koutz wrote:
>
> > Pulling the nose up before TO is what you do on all tricycle
> > airplanes. You
> > apply back pressure to the stick, the nose rises to a certain attitude
>and
> > you hold it there with the stick. When the speed is right the
> > airplane lifts
> > off. Happens all the time. So does aero braking on planes.
> > Problem is in the Q-XX with down elevator there is an awful lot
> > of drag with
> > the elevator deflected. In addition to that, to actually get the nose to
> > rise most pilots will pull in more back pressure than needed then
>suddenly
> > the nose will rise and overshoot takeoff attitude and may lift off
>early,
> > but anyway it IS the start of the COBRA maneuver and I know -that IS
> > certainly dangerous.
>
>Well, the conventional airplane has the tail in back, so when it rotates
>the
>tail becomes less effective at pulling the tail down/nose up. This is a
>natural limiting effect that is absent from the Tri-Q, and all those other
>tri-geared canard airplanes. Ask any Long-EZE flyer; you have to let off on
>the back pressure once you rotate. The only problem I'm concerned with in
>this discussion is the fact that on SOME Tri-Qs, this can't happen until
>the
>airplane is well past what should have been liftoff speed. On these planes,
>someone has advocated using the reflexor to "help" get the nose up, and I
>think that is a dangerous use of the reflexor and that there is a better
>solution to be had in fixing the landing gear geometry.
>
> > With the elevator deflected the canard is trying to created MORE lift
>than
> > it was designed to lift. With the ailerons reflexed UP the main
> > wing is less
> > likely to stall at the same angle of attack No matter what you
> > say the plane
> > will not lift off and actually fly unless each lifting surface
> > provides the
> > exact amount lift required and the plane doesn't care if the
> > elevator is up,
> > down or flushed in or the ailerons are both up, down or flushed in.
>
>"Flaps," whether we call them aileron, elevator, reflexor, or flap, are all
>the same: trailing-edge devices that change the camber of the wing. Flaps
>are most commonly known as "high-lift" devices. When you extend the flaps,
>you increase the maximum available coefficient of lift (Cl_max); when you
>retract the flaps, you decrease the Cl_max; and when you "reflex" the
>flaps,
>you decrease the Cl_max even more. Look it up.
>
>Therefore, when you take off with the reflexor TE-up, the Cl_max of the
>main
>wing is less than it was with the reflexor at neutral. Therefore, in order
>to make whatever Cl is needed to get the airplane off the ground at that
>moment, you'll be lifting off with a smaller margin above the stall for
>that
>main wing. Additionally, since the elevator does not have to be extended so
>far now due to the reflexor "helping" to rotate the plane, you have more
>additional elevator available with which to further rotate the airplane
>than
>if you were taking off with the reflexor neutral.
>
>So, you're right, the airplane will not lift off and actually fly unless
>each lifting surface provides the exact amount of lift required, and the
>plane doesn't care about the control surface positions. BUT, you'll be
>operating with the main wing closer to stall AOA and you'll have a VERY
>effective elevator control available to help you accidentally over-rotate
>and put you into a main wing stall. Or maybe just a little gust will come
>along and start that main wing stall for you. Once the back end drops out,
>look out, buddy!!
>
>I'm not saying that WILL happen, I am saying it MIGHT happen, because we
>don't know what the margin is, and because not everybody has the same
>reflexor position stops, and on and on. I'm only advocating CAUTION in
>using
>TE-up reflexor, and I AM saying that there's a better solution than using
>the reflexor to address the problem of airplanes that won't rotate for
>takeoff in a timely manner.
>
> > I know of only one person that had this happen and his ailerons were
> > reflexed DOWN and he was correcting for a roll on final. He put in
>aileron
> > to correct and the plane rolled the opposite way!
>
>Well, a documented aileron stall! Now we know why the reflexor should not
>be
>allowed to go TE-down...! That's also a good indication of how heavily
>loaded the main wing is at low airspeeds, as per our analysis the other
>day.
>If it can do this with MORE margin above stall AOA (due to TE-down
>reflexor)
>then think how close to stall that main wing might be when you use TE-up
>reflexor.
>
> > People are using it for this purpose -successfully. I recommend it for
> > landing, trimming, cruise control.
>
>All good uses for a reflexor. Just please don't use it to "help" rotate for
>takeoff.
>
>for takeoff, set it like a trim setting in any other airplane, that is, set
>it for the approximate trim setting that you will need on initial climb-out
>after liftoff. In other words, don't use "extra" nose-up reflexor to "help"
>get the nose up.
>
>If you find yourself needing to do something to get the airplane to rotate
>for liftoff, don't succumb to the temptation to use excess reflexor but
>adjust your static ground attitude, instead.
>
> > That is RIGHT. I have experience and I know reflexors are effective. And
> > they also CORRECTED a badly built airplane and made it flyable.
> > The ultimate
> > solution was to CORRECT the flying surface angle of incidence.
>
>They didn't "correct" that badly-built plane, they only made it possible to
>fly it so that you could sort out the real problem of incorrect flying
>surface angles of incidence. You said it yourself: "The ultimate solution
>was to CORRECT the flying surface angle of incidence;" likewise, the
>ultimate solution to fixing the late-rotation problem is to adjust the
>landing gear to give a better ground attitude.
>
>Sure, you can get the airplane to fly using the reflexor to make it rotate,
>but I say that this is not to be construed as a desirable standard
>operation, only a useful tool to help you diagnose the airplane's
>deficiencies during its flight test period. Tho objective of the flight
>test
>period, of course, is to correct such deficiencies, as you finally got
>around to correcting your flying surface incidence angle deficiencies and
>stopped flying around with the reflexor up -- what -- 45 degrees? All I'm
>saying is that taking off with the "trim" (reflexor ) set to full "up" in
>order to get the nosewheel off the ground and then having to re-trim for
>climb is unnatural and potentially unsafe, and that there is an "ultimate
>solution" in establishing a correct static ground attitude.
>
>
> > I do NOT know that the stall speed is effected at ALL by the
> > reflexors, only
> > the attitude of the plane. I have tested this in flight in my
> > airplane and I
> > find no significant stall speed change, just attitude. Near the
> > ground this
> > may be different but I don't have a long stretch of the Great Salt Lake
>to
> > test the effects down low.
>
>I wouldn't expect the stall speed to be significantly changed unless the
>reflexor were significantly deflected, but I thought I recalled you saying
>at one time that you had observed something. My bad. Apparently I'm wrong.
>However, I can think of several reasons to expect the stall speed to change
>with different positions of the reflexor, not the least being that TE-up
>reflexor allows the elevator to be "retracted" like a retracted flap
>instead
>of extended (deflected TE-down) like an extended flap. And we all know that
>wings with extended flaps (TE-down elevator) have lower stalling speeds
>than
>wings with their flaps retracted (elevator more "neutral") as would be
>observed with the reflexor TE-up. I don't suppose that ground effect would
>make much difference.
>
> > I have never had an aft wing stall, that I know of.
>
>I'm just trying to keep it that way. Say, you're not driving a Tri-Q on a
>regular basis, anyway! Your plane is a taildragger, and I don't expect that
>you make a habit of taking off with the reflexor "trim" set anywhere other
>than approximately right for climbout, do you?
>
> > > The reflexor is NOT a band-aid for nosedraggers, it never was. It WAS
>a
> > > band-aid for squirreley taildraggers, that proved to be useful for
> > inflight
> > > trimming, too.
> >
> > I don't know that many Tri-qers would support that assertion. I would
> > certainly want a reflexor if I had a Tri-Q.
>
>Hmmmm, I didn't say the reflexor was not appropriate for Tri-Qs, but
>apparently you and Lynn French both took it that way. Sorry, that's not
>what
>I meant. What I meant was that the reflexor was initially developed for the
>taildragger (Tri-Qs hadn't been invented at that point), and that the
>development of the reflexor was initially in response to the taildragger's
>perceived lack of tailwheel authority. It has since proved useful in more
>ways and is now widely regarded as a necessity for all Q-2xx's, for which I
>agree! That doesn't negate its potential for harm if used incorrectly,
>either.
>
> > >Now it seems that some advocate its use as everything, to the
> > > point of suggesting that it be geared into the control stick or used
>in
> > > place of the front-wing elevators. ARRGH!
> >
> > Who has said this- might be worth a try!
>
>Hey, Rutan effectively did it on the Ams/Oil racer when he geared the
>T-tail
>to the control stick. It worked for them, but we don't have the benefit of
>their expertise. Anyhow, I bet they had a separate trim system and that
>they
>didn't take off with the trim set to full up with the intention of suddenly
>re-trimming as soon as they broke ground.
>
> > > The current discussion centers around the suggestion to use the
>reflexor
> > to
> > > "fix" a tri-Q that won't rotate for takeoff.
> >
> > This is not a "fix", just a technique I used to get a "new 70 something
> > pilot wanta be" to see that his plane (a Tri-DFly) needs to be
> > rotated to a
> > certain attitude and held there until the plane is ready to fly off. He
> > couldn't handle the quick nose rotation at about takeoff speed. I also
> > showed him the effectiveness of the reflexor.
>
>Okay, apples and oranges? I'm trying to discuss apples (Tri-Qs that won't
>rotate for takeoff) and you're talking oranges (a teaching demonstration in
>an airplane that presumably did not "need" extra help rotating for
>liftoff).
>
> > >I stand on my conviction that the CORRECT solution to this problem is
>to
> > either lengthen the nose gear or
> > > shorten the main gear (or both) and, maybe, move the main gear
>forward.
> >
> > How come regular tri geared plane designers don't use this design
> > technique.
>
>They don't have to! They generally aren't elevator limited like canards
>are.
>The conventional airplane's stabilizer/elevator is most effective at
>lifting
>the nose when it is at its most negative angle (nose down), and it loses
>authority as the airplane rotates nose up. The canard's stabilizer/elevator
>(canard) is at its LEAST effective for lifting the nose when the airplane
>is
>nose down, and it becomes MORE effective as the airplane rotates nose up.
>Hence my assertion from the get-go of this whole discussion that the
>correct
>fix for an airplane that rotates late is to make the airplane sit more
>nose-up by altering the landing gear. A more nose-up stance will make the
>canard/elevator initially more effective at lifting the nose and allow the
>nose to be lifted at a lower speed/sooner during the takeoff roll.
>
> > That is why we are supposed to test each new airplane, because
> > each plane IS
> > unique, even though they are similar.
>
>Yessir!
>
> > > I believe that a properly set up Tri-Q should be able to high-speed
>taxi
> > on
> > > the main gear using elevator alone. It will probably not be able to
> > initiate
> > > nose-wheel liftoff as early in the takeoff run as a
> > conventional airplane,
> > > but a positive rotation to takeoff attitude should be available
> > well below
> > > actual liftoff speed. This is a simple result of the fact that the
>main
> > gear
> > > is ahead of the main wing.
> >
> > That IS my point exactly! A "properly set up" Tri-Q may not need
> > a reflexor,
> > but a "new plane" certainly might and they aren't that hard to put in. I
> > think flyers of these planes would put them in again- you might consider
>a
> > reflexor too!
>
>Ummm, I am not advocating getting rid of reflexors or not having them, just
>not over-USING them for stuff that is better addressed in other ways. Sure,
>in a new plane you can take the test-pilot risk (if you know what you're
>looking for) and use the reflexor to make up for a deficiency long enough
>to
>diagnose and correct that deficiency. Just let's not make the temporary use
>into a standard operating procedure and ignore the opportunity to actually
>correct the inadequacy.
>
>
>David J. Gall
>I'm tired, so I'm not proof-reading tonight. Any errors are the fault of my
>computer not being smart enough to know what I'm trying to say wighout me
>acutally hvaing to yas ti. :-)
>

_________________________________________________________________
The new MSN 8: advanced junk mail protection and 2 months FREE*
http://join.msn.com/?page=features/junkmail


Yahoo! Groups Sponsor



To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://www.quickiebuilders.org



Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

It may mean that it could use a little more canard incidience. In cruise the elevator sets at about 1/4 inch below the trailing edge. I have talked to others and they have said that the elevator is in the same position on their planes. In a Tri gear with full down reflexor it has the effect of holding the nose on the ground, in a tail wheel plane it would probably have the effect of lifting the tail. Kelly

From: "paulbuckley" <paulbuckley@...>
Reply-To: Q-LIST@...
To: <Q-LIST@...>
Subject: Re: [Q-LIST] Re: Reflexor
Date: Thu, 22 May 2003 15:41:41 +0100

Hi Kelly

Does this not indicate that you could do with more canard incidence?
Do you have any canard incidence or was the water line set level?
When in cruise do you set it in order to 'fair in' the elevators (zero deflection)?

Paul Buckley
Cheshire, England
Tri Q-200
90% finished,..90% to go!
Original Message -----
From: Kelly Poor
To: Q-LIST@...
Sent: Thursday, May 22, 2003 2:37 PM
Subject: RE: [Q-LIST] Re: Reflexor


On my second take off in my Tri-Q I made the mistake of having the refexor
all the way down. The airplane would not lift off. I had to use alot of
back pressure on the stick to lift it off, which I should have not done.
After lift off while holding some serous back pressure to try to keep it
flying I cut the power and came back down with a few bounces. I learned a
lesson though. Part of the Pre takeoff check list is reflexor up. In my
plane the reflexor down is even with the wing, and deflects 3 or 4 degrees
when all the way up. Where the reflexor is set in cruise depends on how
heavy the plane is loaded. With a light load the refexor is set more in the
upper half of the trave, the heavier it is loaded the more down I need to
set it. I would like to hear what some other Q's relexor travel is, and
where they set it for take off and in cruise conditons. Kelly


>From: "David J. Gall" <David@...>
>Reply-To: Q-LIST@...
>To: <Q-LIST@...>
>Subject: RE: [Q-LIST] Re: Reflexor
>Date: Thu, 22 May 2003 00:45:26 -0400
>
>Larry Koutz wrote:
>
> > Pulling the nose up before TO is what you do on all tricycle
> > airplanes. You
> > apply back pressure to the stick, the nose rises to a certain
attitude
>and
> > you hold it there with the stick. When the speed is right the
> > airplane lifts
> > off. Happens all the time. So does aero braking on planes.
> > Problem is in the Q-XX with down elevator there is an awful lot
> > of drag with
> > the elevator deflected. In addition to that, to actually get the
nose to
> > rise most pilots will pull in more back pressure than needed then
>suddenly
> > the nose will rise and overshoot takeoff attitude and may lift off
>early,
> > but anyway it IS the start of the COBRA maneuver and I know -that IS
> > certainly dangerous.
>
>Well, the conventional airplane has the tail in back, so when it
rotates
>the
>tail becomes less effective at pulling the tail down/nose up. This is a
>natural limiting effect that is absent from the Tri-Q, and all those
other
>tri-geared canard airplanes. Ask any Long-EZE flyer; you have to let
off on
>the back pressure once you rotate. The only problem I'm concerned with
in
>this discussion is the fact that on SOME Tri-Qs, this can't happen
until
>the
>airplane is well past what should have been liftoff speed. On these
planes,
>someone has advocated using the reflexor to "help" get the nose up, and
I
>think that is a dangerous use of the reflexor and that there is a
better
>solution to be had in fixing the landing gear geometry.
>
> > With the elevator deflected the canard is trying to created MORE
lift
>than
> > it was designed to lift. With the ailerons reflexed UP the main
> > wing is less
> > likely to stall at the same angle of attack No matter what you
> > say the plane
> > will not lift off and actually fly unless each lifting surface
> > provides the
> > exact amount lift required and the plane doesn't care if the
> > elevator is up,
> > down or flushed in or the ailerons are both up, down or flushed in.
>
>"Flaps," whether we call them aileron, elevator, reflexor, or flap, are
all
>the same: trailing-edge devices that change the camber of the wing.
Flaps
>are most commonly known as "high-lift" devices. When you extend the
flaps,
>you increase the maximum available coefficient of lift (Cl_max); when
you
>retract the flaps, you decrease the Cl_max; and when you "reflex" the
>flaps,
>you decrease the Cl_max even more. Look it up.
>
>Therefore, when you take off with the reflexor TE-up, the Cl_max of the
>main
>wing is less than it was with the reflexor at neutral. Therefore, in
order
>to make whatever Cl is needed to get the airplane off the ground at
that
>moment, you'll be lifting off with a smaller margin above the stall for
>that
>main wing. Additionally, since the elevator does not have to be
extended so
>far now due to the reflexor "helping" to rotate the plane, you have
more
>additional elevator available with which to further rotate the airplane
>than
>if you were taking off with the reflexor neutral.
>
>So, you're right, the airplane will not lift off and actually fly
unless
>each lifting surface provides the exact amount of lift required, and
the
>plane doesn't care about the control surface positions. BUT, you'll be
>operating with the main wing closer to stall AOA and you'll have a VERY
>effective elevator control available to help you accidentally
over-rotate
>and put you into a main wing stall. Or maybe just a little gust will
come
>along and start that main wing stall for you. Once the back end drops
out,
>look out, buddy!!
>
>I'm not saying that WILL happen, I am saying it MIGHT happen, because
we
>don't know what the margin is, and because not everybody has the same
>reflexor position stops, and on and on. I'm only advocating CAUTION in
>using
>TE-up reflexor, and I AM saying that there's a better solution than
using
>the reflexor to address the problem of airplanes that won't rotate for
>takeoff in a timely manner.
>
> > I know of only one person that had this happen and his ailerons were
> > reflexed DOWN and he was correcting for a roll on final. He put in
>aileron
> > to correct and the plane rolled the opposite way!
>
>Well, a documented aileron stall! Now we know why the reflexor should
not
>be
>allowed to go TE-down...! That's also a good indication of how heavily
>loaded the main wing is at low airspeeds, as per our analysis the other
>day.
>If it can do this with MORE margin above stall AOA (due to TE-down
>reflexor)
>then think how close to stall that main wing might be when you use
TE-up
>reflexor.
>
> > People are using it for this purpose -successfully. I recommend it
for
> > landing, trimming, cruise control.
>
>All good uses for a reflexor. Just please don't use it to "help" rotate
for
>takeoff.
>
>for takeoff, set it like a trim setting in any other airplane, that is,
set
>it for the approximate trim setting that you will need on initial
climb-out
>after liftoff. In other words, don't use "extra" nose-up reflexor to
"help"
>get the nose up.
>
>If you find yourself needing to do something to get the airplane to
rotate
>for liftoff, don't succumb to the temptation to use excess reflexor but
>adjust your static ground attitude, instead.
>
> > That is RIGHT. I have experience and I know reflexors are effective.
And
> > they also CORRECTED a badly built airplane and made it flyable.
> > The ultimate
> > solution was to CORRECT the flying surface angle of incidence.
>
>They didn't "correct" that badly-built plane, they only made it
possible to
>fly it so that you could sort out the real problem of incorrect flying
>surface angles of incidence. You said it yourself: "The ultimate
solution
>was to CORRECT the flying surface angle of incidence;" likewise, the
>ultimate solution to fixing the late-rotation problem is to adjust the
>landing gear to give a better ground attitude.
>
>Sure, you can get the airplane to fly using the reflexor to make it
rotate,
>but I say that this is not to be construed as a desirable standard
>operation, only a useful tool to help you diagnose the airplane's
>deficiencies during its flight test period. Tho objective of the flight
>test
>period, of course, is to correct such deficiencies, as you finally got
>around to correcting your flying surface incidence angle deficiencies
and
>stopped flying around with the reflexor up -- what -- 45 degrees? All
I'm
>saying is that taking off with the "trim" (reflexor ) set to full "up"
in
>order to get the nosewheel off the ground and then having to re-trim
for
>climb is unnatural and potentially unsafe, and that there is an
"ultimate
>solution" in establishing a correct static ground attitude.
>
>
> > I do NOT know that the stall speed is effected at ALL by the
> > reflexors, only
> > the attitude of the plane. I have tested this in flight in my
> > airplane and I
> > find no significant stall speed change, just attitude. Near the
> > ground this
> > may be different but I don't have a long stretch of the Great Salt
Lake
>to
> > test the effects down low.
>
>I wouldn't expect the stall speed to be significantly changed unless
the
>reflexor were significantly deflected, but I thought I recalled you
saying
>at one time that you had observed something. My bad. Apparently I'm
wrong.
>However, I can think of several reasons to expect the stall speed to
change
>with different positions of the reflexor, not the least being that
TE-up
>reflexor allows the elevator to be "retracted" like a retracted flap
>instead
>of extended (deflected TE-down) like an extended flap. And we all know
that
>wings with extended flaps (TE-down elevator) have lower stalling speeds
>than
>wings with their flaps retracted (elevator more "neutral") as would be
>observed with the reflexor TE-up. I don't suppose that ground effect
would
>make much difference.
>
> > I have never had an aft wing stall, that I know of.
>
>I'm just trying to keep it that way. Say, you're not driving a Tri-Q on
a
>regular basis, anyway! Your plane is a taildragger, and I don't expect
that
>you make a habit of taking off with the reflexor "trim" set anywhere
other
>than approximately right for climbout, do you?
>
> > > The reflexor is NOT a band-aid for nosedraggers, it never was. It
WAS
>a
> > > band-aid for squirreley taildraggers, that proved to be useful for
> > inflight
> > > trimming, too.
> >
> > I don't know that many Tri-qers would support that assertion. I
would
> > certainly want a reflexor if I had a Tri-Q.
>
>Hmmmm, I didn't say the reflexor was not appropriate for Tri-Qs, but
>apparently you and Lynn French both took it that way. Sorry, that's not
>what
>I meant. What I meant was that the reflexor was initially developed for
the
>taildragger (Tri-Qs hadn't been invented at that point), and that the
>development of the reflexor was initially in response to the
taildragger's
>perceived lack of tailwheel authority. It has since proved useful in
more
>ways and is now widely regarded as a necessity for all Q-2xx's, for
which I
>agree! That doesn't negate its potential for harm if used incorrectly,
>either.
>
> > >Now it seems that some advocate its use as everything, to the
> > > point of suggesting that it be geared into the control stick or
used
>in
> > > place of the front-wing elevators. ARRGH!
> >
> > Who has said this- might be worth a try!
>
>Hey, Rutan effectively did it on the Ams/Oil racer when he geared the
>T-tail
>to the control stick. It worked for them, but we don't have the benefit
of
>their expertise. Anyhow, I bet they had a separate trim system and that
>they
>didn't take off with the trim set to full up with the intention of
suddenly
>re-trimming as soon as they broke ground.
>
> > > The current discussion centers around the suggestion to use the
>reflexor
> > to
> > > "fix" a tri-Q that won't rotate for takeoff.
> >
> > This is not a "fix", just a technique I used to get a "new 70
something
> > pilot wanta be" to see that his plane (a Tri-DFly) needs to be
> > rotated to a
> > certain attitude and held there until the plane is ready to fly off.
He
> > couldn't handle the quick nose rotation at about takeoff speed. I
also
> > showed him the effectiveness of the reflexor.
>
>Okay, apples and oranges? I'm trying to discuss apples (Tri-Qs that
won't
>rotate for takeoff) and you're talking oranges (a teaching
demonstration in
>an airplane that presumably did not "need" extra help rotating for
>liftoff).
>
> > >I stand on my conviction that the CORRECT solution to this problem
is
>to
> > either lengthen the nose gear or
> > > shorten the main gear (or both) and, maybe, move the main gear
>forward.
> >
> > How come regular tri geared plane designers don't use this design
> > technique.
>
>They don't have to! They generally aren't elevator limited like canards
>are.
>The conventional airplane's stabilizer/elevator is most effective at
>lifting
>the nose when it is at its most negative angle (nose down), and it
loses
>authority as the airplane rotates nose up. The canard's
stabilizer/elevator
>(canard) is at its LEAST effective for lifting the nose when the
airplane
>is
>nose down, and it becomes MORE effective as the airplane rotates nose
up.
>Hence my assertion from the get-go of this whole discussion that the
>correct
>fix for an airplane that rotates late is to make the airplane sit more
>nose-up by altering the landing gear. A more nose-up stance will make
the
>canard/elevator initially more effective at lifting the nose and allow
the
>nose to be lifted at a lower speed/sooner during the takeoff roll.
>
> > That is why we are supposed to test each new airplane, because
> > each plane IS
> > unique, even though they are similar.
>
>Yessir!
>
> > > I believe that a properly set up Tri-Q should be able to
high-speed
>taxi
> > on
> > > the main gear using elevator alone. It will probably not be able
to
> > initiate
> > > nose-wheel liftoff as early in the takeoff run as a
> > conventional airplane,
> > > but a positive rotation to takeoff attitude should be available
> > well below
> > > actual liftoff speed. This is a simple result of the fact that the
>main
> > gear
> > > is ahead of the main wing.
> >
> > That IS my point exactly! A "properly set up" Tri-Q may not need
> > a reflexor,
> > but a "new plane" certainly might and they aren't that hard to put
in. I
> > think flyers of these planes would put them in again- you might
consider
>a
> > reflexor too!
>
>Ummm, I am not advocating getting rid of reflexors or not having them,
just
>not over-USING them for stuff that is better addressed in other ways.
Sure,
>in a new plane you can take the test-pilot risk (if you know what
you're
>looking for) and use the reflexor to make up for a deficiency long
enough
>to
>diagnose and correct that deficiency. Just let's not make the temporary
use
>into a standard operating procedure and ignore the opportunity to
actually
>correct the inadequacy.
>
>
>David J. Gall
>I'm tired, so I'm not proof-reading tonight. Any errors are the fault
of my
>computer not being smart enough to know what I'm trying to say wighout
me
>acutally hvaing to yas ti. :-)
>

_________________________________________________________________
The new MSN 8: advanced junk mail protection and 2 months FREE*
http://join.msn.com/?page=features/junkmail


Yahoo! Groups Sponsor



To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://www.quickiebuilders.org



Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

_________________________________________________________________
The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail

My TriQ200 behaves about the same. I don't use aileron-down reflexer at all. At high speed ailerons and elevator are neutral. I mounted the canard half a degree nose up. I know Scott Swing suggested mounting the canard 1 degree nose up at some point.

Dave Chalmers
TriQ200 N4016G (70 hrs)
Redmond, WA

no clue. Haven't measured.

Kelly,

My reflexor is set at zero on takeoff as well as in flight. I use
full up reflexor it to stick the tail on landing and down reflexor to
lower the nose in flight with a heavy aft load.

Jim Patillo. N46JP Tail Draggin Q200 N46JP (real pilots drag their
tails, Kelly! hehehehe).Did you get your temper foam and seats from
Allen?

The suggestion to mount the canard 1 degree up was for the GU canard only.
There was never a suggestion to mount the LS1 at any angle other than 0-0.
Bob F.
N200QK

Me too, except I preset my reflexor pitch up a couple of degrees when light
(forward CG). Makes the airplane lift off with the same back pressure in
either case.

Bob F.
N200QK

Unless I'm missing something, it seems to me that the stall angle of an
airfoil has nothing to do with load, and everything to do with angle of
attack. And since the main wing doesn't exist in isolation from the canard,
its AOA is intimately tied to that of the canard. If you reflex the ailerons
up, you reduce the AOA of that section of the wing which should reduce its
stall tendency RELATIVE TO THE CANARD. The danger arises because the reduced
lift on the rear wing means that the allowable CG range must move forward.
Imagine making the rear wing very small, like a Cessna. The CG would move
forward to a relative position similar to the Cessna. If you reduce the lift
of a Q's rear wing enough so that the airplane is now loaded aft of its
allowable aft limit, you risk main wing stall. A warning that you are
approaching that point is that the airplane would approach and then go past
the neutral point. It turns out that the only time I need any pitch up
reflexor is when the airplane is already loaded near its forward limit
(solo, no bags, low on main fuel), or like Jim P. said, to stick the
tailwheel down on landing.

For what it's worth...

Bob F.
N200QK

Bob, do you have a reference for that? I was under the impression that
it applied to the LS1. I was looking thru the Q-Talk index and found a
couple of references to incidence. May 87 p14 Scott Swing suggests
making sure a level placed on the trailing edge of the wing and canard
as close to the fuselage as possible reads 1 degree more on canard than
wing (on a Q200). This isn't the same as the level line but is obviously
close to the same relative measurement. I just measured mine and have 0
degree difference between wing and canard at that point. May 89 p9 Dick
Barbour talks about incidence and says that most people install the LS-1
somewhere between 0 and +1 degree. Does anyone have a written reference
to the incidence suggestion or are we working from memory?

Dave Chalmers
TriQ200 4016G (70hrs)
Redmond, WA

Kelly Poor wrote:

<snip>

In a Tri gear with full down reflexor it has the effect of
holding the nose on the ground, in a tail wheel plane it would probably
have the effect of lifting the tail.

Kelly, again, if I read your description right, you really
have no "down" to your reflexor, only up and neutral.

When you reflexor lever is in the "down" position, it's as if you
didn't have a reflexor installed at all.

I know I'm splitting hairs on the terminology, but we all need to be
on the same page when we say the reflexor is up, down or neutral (in
trail).

The fact that you really need the reflexor to do a normal take-off
speaks either to your rigging, or the Tri-Q in general... I'm thinking
a combination of both.

Pat

OK, lets talk about the T-tail again,

If one (ie. me) were to mount a T-tail that had limited travel, such that
the max deflection of the T-tail was slightly small than being equal and
opposite to pitch of the plane when the canard stalls (at the aft CG
limit) Ideally, the T-tail would only have negative (nose-down effect)
travel, as the opposite would not serve any useful purpose except to
allow one to exceed the aft CG limit, which would not be good.

The effect of the T-tail surface would be to help lift the nose at low
pitch and would be neutralized at high pitch (and low airspeeds) because
it would be parallel to the slipstream at high pitch. Bottom line, at
high angles of attack,the wings would be flying like a stock Q200 because
of the only zero moment contribution of the fully deflected T-tail.

Why install another "complicating device"? Because I see some obvious
advantages to the T-tail, done right:

1. As you mention, during transition from ground vehicle to air vehicle,
the effect of a de-lifting tail is naturally diminished by increased
rotation (like in the Cessna). This is a consideration for us guys with
the wheel on the wrong end.

2. The T-tail will "lever" the nose up to take-off attitude at high speed
taxi (pivoting on the mains). Then it would butt-out of the equation as
soon as the take-off pitch was achieved.

3. A T-tail with stop-limited full deflection would tend to dampen the
pitch-buck by having causing increased downforce on the tail upon lowered
pitch-angle with canard-stall.

4. The deflected T-tail would only produce high additonal loading on the
main wing when the main wing was at low angles of attack and therefore,
NOT prone to stalling. As I mentioned before, at high angles of attack
T-tail down-force would fall to zero, unlike the reflexor which has
actually represents an alteration to the camber of the wing ---By the
way, as I see it, with the aileron reflexed up, if the reflexed main-wing
were to stall, it should be a tip or midwing stall..is that correct?--

5. The T-tail at high-speed cruise (if that is even possible with all the
weight and drag I am adding to my plane :-), could be used to counter
some of the pitching moment of the canard that you showed us in your
table, potentially causing both wings fly more efficiently.

6. At anything other than full-deflection, the T-tail would have a
positive angle of attack when the plane is at high pitch angles. In this
case the T-tail would tend to UNLOAD the mainwing, thus further limiting
the possibility of a mainwing stall. It would also have the effect of
lowering the deck angle at pitch-buck...or potentially, because of added
tail-plane lift (three lifting surfaces), it might eliminate the
possiiblity of pitchbuck. This would be a good thing when landing the
tri-gear.

I think the critical design issue is how much wing area to have on the
T-tail in order to give it the right behavior.

Please tell me where/if I am wrong.

Jay

Original Message <<<<<<<<<<<<<<<<<<

On 5/21/03, 10:45:26 PM, "David J. Gall" <David@...> wrote regarding
RE: [Q-LIST] Re: Reflexor:

Larry Koutz wrote:

Pulling the nose up before TO is what you do on all tricycle
airplanes. You
apply back pressure to the stick, the nose rises to a certain attitude

and

you hold it there with the stick. When the speed is right the
airplane lifts
off. Happens all the time. So does aero braking on planes.
Problem is in the Q-XX with down elevator there is an awful lot
of drag with
the elevator deflected. In addition to that, to actually get the nose to
rise most pilots will pull in more back pressure than needed then

suddenly

the nose will rise and overshoot takeoff attitude and may lift off early,
but anyway it IS the start of the COBRA maneuver and I know -that IS
certainly dangerous.

Well, the conventional airplane has the tail in back, so when it rotates

the

tail becomes less effective at pulling the tail down/nose up. This is a
natural limiting effect that is absent from the Tri-Q, and all those

other

tri-geared canard airplanes. Ask any Long-EZE flyer; you have to let off

on

the back pressure once you rotate. The only problem I'm concerned with in
this discussion is the fact that on SOME Tri-Qs, this can't happen until

the

airplane is well past what should have been liftoff speed. On these

planes,

someone has advocated using the reflexor to "help" get the nose up, and I
think that is a dangerous use of the reflexor and that there is a better
solution to be had in fixing the landing gear geometry.

With the elevator deflected the canard is trying to created MORE lift

than

it was designed to lift. With the ailerons reflexed UP the main
wing is less
likely to stall at the same angle of attack No matter what you
say the plane
will not lift off and actually fly unless each lifting surface
provides the
exact amount lift required and the plane doesn't care if the
elevator is up,
down or flushed in or the ailerons are both up, down or flushed in.

"Flaps," whether we call them aileron, elevator, reflexor, or flap, are

all

the same: trailing-edge devices that change the camber of the wing. Flaps
are most commonly known as "high-lift" devices. When you extend the

flaps,

you increase the maximum available coefficient of lift (Cl_max); when you
retract the flaps, you decrease the Cl_max; and when you "reflex" the

flaps,

you decrease the Cl_max even more. Look it up.

Therefore, when you take off with the reflexor TE-up, the Cl_max of the

main

wing is less than it was with the reflexor at neutral. Therefore, in

order

to make whatever Cl is needed to get the airplane off the ground at that
moment, you'll be lifting off with a smaller margin above the stall for

that

main wing. Additionally, since the elevator does not have to be extended

so

far now due to the reflexor "helping" to rotate the plane, you have more
additional elevator available with which to further rotate the airplane

than

if you were taking off with the reflexor neutral.

So, you're right, the airplane will not lift off and actually fly unless
each lifting surface provides the exact amount of lift required, and the
plane doesn't care about the control surface positions. BUT, you'll be
operating with the main wing closer to stall AOA and you'll have a VERY
effective elevator control available to help you accidentally over-rotate
and put you into a main wing stall. Or maybe just a little gust will come
along and start that main wing stall for you. Once the back end drops

out,

look out, buddy!!

I'm not saying that WILL happen, I am saying it MIGHT happen, because we
don't know what the margin is, and because not everybody has the same
reflexor position stops, and on and on. I'm only advocating CAUTION in

using

TE-up reflexor, and I AM saying that there's a better solution than using
the reflexor to address the problem of airplanes that won't rotate for
takeoff in a timely manner.

I know of only one person that had this happen and his ailerons were
reflexed DOWN and he was correcting for a roll on final. He put in

aileron

to correct and the plane rolled the opposite way!

Well, a documented aileron stall! Now we know why the reflexor should not

be

allowed to go TE-down...! That's also a good indication of how heavily
loaded the main wing is at low airspeeds, as per our analysis the other

day.

If it can do this with MORE margin above stall AOA (due to TE-down

reflexor)

then think how close to stall that main wing might be when you use TE-up
reflexor.

People are using it for this purpose -successfully. I recommend it for
landing, trimming, cruise control.

All good uses for a reflexor. Just please don't use it to "help" rotate

for

takeoff.

for takeoff, set it like a trim setting in any other airplane, that is,

set

it for the approximate trim setting that you will need on initial

climb-out

after liftoff. In other words, don't use "extra" nose-up reflexor to

"help"

get the nose up.

If you find yourself needing to do something to get the airplane to

rotate

for liftoff, don't succumb to the temptation to use excess reflexor but
adjust your static ground attitude, instead.

That is RIGHT. I have experience and I know reflexors are effective. And
they also CORRECTED a badly built airplane and made it flyable.
The ultimate
solution was to CORRECT the flying surface angle of incidence.

They didn't "correct" that badly-built plane, they only made it possible

to

fly it so that you could sort out the real problem of incorrect flying
surface angles of incidence. You said it yourself: "The ultimate solution
was to CORRECT the flying surface angle of incidence;" likewise, the
ultimate solution to fixing the late-rotation problem is to adjust the
landing gear to give a better ground attitude.

Sure, you can get the airplane to fly using the reflexor to make it

rotate,

but I say that this is not to be construed as a desirable standard
operation, only a useful tool to help you diagnose the airplane's
deficiencies during its flight test period. Tho objective of the flight

test

period, of course, is to correct such deficiencies, as you finally got
around to correcting your flying surface incidence angle deficiencies and
stopped flying around with the reflexor up -- what -- 45 degrees? All I'm
saying is that taking off with the "trim" (reflexor ) set to full "up" in
order to get the nosewheel off the ground and then having to re-trim for
climb is unnatural and potentially unsafe, and that there is an "ultimate
solution" in establishing a correct static ground attitude.

I do NOT know that the stall speed is effected at ALL by the
reflexors, only
the attitude of the plane. I have tested this in flight in my
airplane and I
find no significant stall speed change, just attitude. Near the
ground this
may be different but I don't have a long stretch of the Great Salt Lake

to

test the effects down low.

I wouldn't expect the stall speed to be significantly changed unless the
reflexor were significantly deflected, but I thought I recalled you

saying

at one time that you had observed something. My bad. Apparently I'm

wrong.

However, I can think of several reasons to expect the stall speed to

change

with different positions of the reflexor, not the least being that TE-up
reflexor allows the elevator to be "retracted" like a retracted flap

instead

of extended (deflected TE-down) like an extended flap. And we all know

that

wings with extended flaps (TE-down elevator) have lower stalling speeds

than

wings with their flaps retracted (elevator more "neutral") as would be
observed with the reflexor TE-up. I don't suppose that ground effect

would

make much difference.

I have never had an aft wing stall, that I know of.

I'm just trying to keep it that way. Say, you're not driving a Tri-Q on a
regular basis, anyway! Your plane is a taildragger, and I don't expect

that

you make a habit of taking off with the reflexor "trim" set anywhere

other

than approximately right for climbout, do you?

The reflexor is NOT a band-aid for nosedraggers, it never was. It WAS a
band-aid for squirreley taildraggers, that proved to be useful for

inflight

trimming, too.

I don't know that many Tri-qers would support that assertion. I would
certainly want a reflexor if I had a Tri-Q.

Hmmmm, I didn't say the reflexor was not appropriate for Tri-Qs, but
apparently you and Lynn French both took it that way. Sorry, that's not

what

I meant. What I meant was that the reflexor was initially developed for

the

taildragger (Tri-Qs hadn't been invented at that point), and that the
development of the reflexor was initially in response to the

taildragger's

perceived lack of tailwheel authority. It has since proved useful in more
ways and is now widely regarded as a necessity for all Q-2xx's, for which

I

agree! That doesn't negate its potential for harm if used incorrectly,
either.

Now it seems that some advocate its use as everything, to the
point of suggesting that it be geared into the control stick or used in
place of the front-wing elevators. ARRGH!

Who has said this- might be worth a try!

Hey, Rutan effectively did it on the Ams/Oil racer when he geared the

T-tail

to the control stick. It worked for them, but we don't have the benefit

of

their expertise. Anyhow, I bet they had a separate trim system and that

they

didn't take off with the trim set to full up with the intention of

suddenly

re-trimming as soon as they broke ground.

The current discussion centers around the suggestion to use the reflexor

to

"fix" a tri-Q that won't rotate for takeoff.

This is not a "fix", just a technique I used to get a "new 70 something
pilot wanta be" to see that his plane (a Tri-DFly) needs to be
rotated to a
certain attitude and held there until the plane is ready to fly off. He
couldn't handle the quick nose rotation at about takeoff speed. I also
showed him the effectiveness of the reflexor.

Okay, apples and oranges? I'm trying to discuss apples (Tri-Qs that won't
rotate for takeoff) and you're talking oranges (a teaching demonstration

in

an airplane that presumably did not "need" extra help rotating for

liftoff).

I stand on my conviction that the CORRECT solution to this problem is to

either lengthen the nose gear or

shorten the main gear (or both) and, maybe, move the main gear forward.

How come regular tri geared plane designers don't use this design
technique.

They don't have to! They generally aren't elevator limited like canards

are.

The conventional airplane's stabilizer/elevator is most effective at

lifting

the nose when it is at its most negative angle (nose down), and it loses
authority as the airplane rotates nose up. The canard's

stabilizer/elevator

(canard) is at its LEAST effective for lifting the nose when the airplane

is

nose down, and it becomes MORE effective as the airplane rotates nose up.
Hence my assertion from the get-go of this whole discussion that the

correct

fix for an airplane that rotates late is to make the airplane sit more
nose-up by altering the landing gear. A more nose-up stance will make the
canard/elevator initially more effective at lifting the nose and allow

the

nose to be lifted at a lower speed/sooner during the takeoff roll.

That is why we are supposed to test each new airplane, because
each plane IS
unique, even though they are similar.

Yessir!

I believe that a properly set up Tri-Q should be able to high-speed taxi

on

the main gear using elevator alone. It will probably not be able to

initiate

nose-wheel liftoff as early in the takeoff run as a

conventional airplane,

but a positive rotation to takeoff attitude should be available

well below

actual liftoff speed. This is a simple result of the fact that the main

gear

is ahead of the main wing.

That IS my point exactly! A "properly set up" Tri-Q may not need
a reflexor,
but a "new plane" certainly might and they aren't that hard to put in. I
think flyers of these planes would put them in again- you might consider

a

reflexor too!

Ummm, I am not advocating getting rid of reflexors or not having them,

just

not over-USING them for stuff that is better addressed in other ways.

Sure,

in a new plane you can take the test-pilot risk (if you know what you're
looking for) and use the reflexor to make up for a deficiency long enough

to

diagnose and correct that deficiency. Just let's not make the temporary

use

into a standard operating procedure and ignore the opportunity to

actually

correct the inadequacy.

David J. Gall
I'm tired, so I'm not proof-reading tonight. Any errors are the fault of

my

computer not being smart enough to know what I'm trying to say wighout me
acutally hvaing to yas ti. :-)

To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://www.quickiebuilders.org

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

That sounds like a perfect result. I also have mounted the canard 1/2 degree up and aelerons neutral and hoping for elevators neutral . Will report after test flight.
Peter