REFLECTOR:Wing/Canard/Fuselage Incidence

[Alex Balic]

Mike,
the incidence of the canard relative to the wing should not change- what
needs to change is the level line on the fuselage when you jig the flying
surfaces- I will bet that you had the fuselage a bit nose high when you set
the incidences of the wing and the canard- just point the nose lower, and
then re- jig both surfaces, and the aircraft will fly with the nose more
down and the relationship between the wing and the canard will remain the
same.
Alex

working on exhaust system at the moment- fun, fun, fun





-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
Behalf Of mike deeter
Sent: Sunday, March 07, 2004 7:47 PM
To: reflector@tvbf.org
Subject: Re: REFLECTOR:Wing/Canard/Fuselage Incidence


Ronnie and Pat:

Thanks a bunch for your postings.  I spoke to Alan on
Friday and he gave me a bunch of info, most of it
contained in the blurb Ronnie found in the archives.

Pat, I wasn't clear as to my measurements.  I agree w/
you in that I don't feel comfortable changing the
wing/canard relationship if they're correct.  My
problem is both incidence jigs don't level at the same
time and the difference is in the direction where
they're closer in incidence than they should be.
Probably not much but may bear changing.

Hmm.  Gives me lots of stuff to chew on but I feel I
can at least make an informed decision as to what, if
anything, to do.

Thanks,

Mike


--- Ronnie Brown <romott@adelphia.net> wrote:
> I found this in the Archives.  This is by Alan Shaw:
>
> At cruise I like a Velocity with 1/2" of reflex
> single pilot.  This rig
> makes
> for a faster cruise and slower landing.  Your case
> may be a little extreme
> and
> require 1/2 degree less incidence in the canard.  A
> quick fix is to put a
> 1/32" washer on both outboard top wing bolts...thus
> decreasing the
> difference
> between the incidence angle of the canard and main
> wing.  This way you can
> test fly the change before you go through the hassle
> of changing the canard.
>
> Like I said, I like a Velocity that requires full
> forward trim and full
> forward stick by the pilot when solo, wide open at
> sea level.  This will
> leave
> more elevator authority (flare!) when you are slow
> and loaded.  It should
> also
> trim fine at the lower indicated airspeeds of cruise
> at 8,000' and above.
> It's a common problem with new Velocities that the
> new owners fly in this
> unusual mode of solo, full throttle, low altitude
> and then re-rig there A/C
> to
> "fix" this quirk that really just makes things
> better on the slow end of the
> flight envelope.
>
> With such a powerful canard some people are worried
> about deep stall.  Even
> if
> you could "make" it deep stall I doubt that you
> push your canard past
> normal
> bucking into the violent bucking and rolling etc.
> that normally precedes the
> "big one".
>
> What prevents deep stall is not just as simple as
> the difference in wing
> loading between the two wings but all there
> differences in characteristics
> as
> whole.  That means incidence angle, aspect ratio,
> camber, leading edge
> radius
> and many other lesser factors.  In other words, if
> you decrease the canard
> incidence and/or cut it shorter (lower the aspect
> ratio) then you have
> actually increased two factors for deep stall
> potential.  On the other hand
> this change has increased you wing loading on the
> canard and also made it
> harder for you to pull the nose up too high.  If you
> are confused so am I.
> That's the problem there are so many variables each
> with different
> coefficients of influence over the  wing
> differential we are trying to
> maintain while at the same time trying to get as
> wide a flight envelope as
> possible.
>
> The obvious is to keep the CG in front of the center
> of lift.  The problem
> here is that the main wing/winglet is comprised of
> four different airfoils,
> incident angles and coefficient's of lift.  So where
> exactly is the center
> of
> lift?....well the experts don't seem to agree unless
> they simplify with
> rounded off  "rules of thumb" that are far from the
> truth.
>
> That's why the flight test that Dan, myself and
> especially Jim Patton did
> were
> so important.  When Jim "tickled the dragons tail",
> as he put it,  he found
> the Velocity to have far more low speed stability
> and aft CG capability than
> its other "Easy" counter parts.   As the head of
> NASA's GA stall spin R&D
> program for almost 20 years Jim has pushed
> everything out there way past
> it's
> limits and should know.  In his opinion the STD wing
> Velocity is as good as
> it
> gets in the compromise between stall prevention and
> performance.  Personally
> I
> think the STD Velocity will endure the test of time
> as one of aviation's
> more
> exceptional designs.
>
> Alan
>
> ----- Original Message -----
> From: "Pat Shea" <xl340hp@yahoo.com>
> To: <reflector@tvbf.org>
> Sent: Friday, March 05, 2004 7:32 PM
> Subject: Re: REFLECTOR:Wing/Canard/Fuselage
> Incidence
>
>
> | Mike,
> |
> |  I suspect you wouldn't want to change the
> relative
> | wing-to-canard incidence (deep stall issues,
> etc.).
> | Increasing the incidence of both, however, should
> | cause the nose of the fuselage to be lower in
> flight.
> | In other words, both incidence jigs should still
> | center - the fuselage would just need to be in a
> more
> | nose down attitude than before the incidence
> change.
> |
> |  Of course, the strakes are part of the wing and
> are
> | tied to the fuselage's attitude. Maybe the factory
> | could advise you on how much, if any, change is
> | reasonable.
> |
> | Pat
> |
> | --- mike deeter <iguanamagic@yahoo.com> wrote:
> | > Help for advice re: wing incidence
> | >
> | > I'm sure a bunch of folks have dealt with this
> | > issue.
> | >
> | > My Std Elite RG flies fine but it also seems to
> fly
> | > a
> | > bit fuselage-high in cruise.  Several people,
> | > including one guy w/ an identical Velocity and
> | > set of wings (Alan Shaw's), have remarked on it.
>  I
> | > think so, too, and since that must be a
> high-drag
> | > attitude I want to explore what (if anything,
> since
> | > it
> | > flies fine) to do about it.
> | >
> | > If it's pertinent, my canard is 1/8" to 1/4" up
> when
> | > I'm flying in cruise with a midrange CG.
> | >
> | > Questions:
> | >
> | > 1. I measured the main wings versus the canard
> using
> | > Velocity's incidence jigs and my digital level
> as a
> | > standard and found my canard to be about 0.5
> degrees
> | > leading edge low as compared to the main wing.
> | > Would
> | > raising the canard incidence 0.5 degrees have
> the
> | > effect of lowering the nose in cruise?
> | >
> | > 2.  What about shimming the upper, outboard wing
> | > bolt?
> | > That would seem to raise the angle of incidence
> of
> | > the main wing chord slightly.  Would that bring
> the
> | > nose down in cruise?  I did measure my main
> | > wing/fuselage relationship versus my friend's
> | > Velocity
> | > and found no appreciable difference.  My
> | > calculations
> | > using geometric relations show a 0.030" shim
> | > changing
> | > the chord about 0.43 degrees.  Significant?  Can
> I
> | > get
> | > away with just the outboard bolt or must I shim
> the
> | > inboard wing bolt as well?
> | >
> | > 3.  Any other suggestions?
> | >
>
=== message truncated ===


=====
*******************************************
Mike Deeter
N2011 Test Pilot
iguanamagic@yahoo.com
http://iguanamagic.siegesmund.org
*******************************************

__________________________________
Do you Yahoo!?
Yahoo! Search - Find what youre looking for faster
http://search.yahoo.com
_______________________________________________
To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!  www.tvbf.org/gallery
user:pw = tvbf:jamaicangoose
Check new archives: www.tvbf.org/pipermail
Check old archives: http://www.tvbf.org/archives/velocity/maillist.html