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<p class=MsoNormal><span class=EmailStyle18><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>The
airplane may be flying with positive trim. Try reducing the down thrust or move
the CG back.<o:p></o:p></span></font></span></p>
<p class=MsoNormal><span class=EmailStyle18><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>If it doesn’t
help put it back.<o:p></o:p></span></font></span></p>
<p class=MsoNormal><span class=EmailStyle18><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Jim Hiller<o:p></o:p></span></font></span></p>
<p class=MsoNormal><span class=EmailStyle18><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'><![if !supportEmptyParas]> <![endif]><o:p></o:p></span></font></span></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 color=black
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;color:black'>-----Original
Message-----<br>
<b><span style='font-weight:bold'>From:</span></b>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org]<b><span style='font-weight:
bold'>On Behalf Of </span></b>Michael Wickizer<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, March 07, 2008 8:19
AM<br>
<b><span style='font-weight:bold'>To:</span></b> NSRCA Mailing List<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [NSRCA-discussion] YS
Questions+more - Rolls</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><![if !supportEmptyParas]> <![endif]><o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:
12.0pt;margin-left:.5in'><font size=2 color=black face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;color:black'>Bryan:<br>
<br>
I agree that the plane doesn't know which direction it's flying, but then why
will a plane fly straight and level then pull to the canopy in uplines?
This has been driving Brett and me crazy for over a year. Admittedly, it
a much shorter drive for me:)<br>
<br>
Mike<br>
<br>
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> Date: Thu, 6 Mar 2008 23:13:48 -0500<br>
> From: shinden1@cox.net<br>
> To: nsrca-discussion@lists.nsrca.org<br>
> Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls<br>
> <br>
> Chris ,, the airplane does not know it`s flying horizontal or vertical <br>
> the wings are still lifting whether up or down that s why we can use the
vertical up or down to test this problem ,<br>
> Bryan<br>
> ---- krishlan fitzsimmons <homeremodeling2003@yahoo.com> wrote: <br>
> > Lance, <br>
> > <br>
> > Just a thought though, if going straight up, up straight down, aren't
the up and down ailerons both inducing equal drag, no lift? I've often wondered
if our straight up test is actually a perfect test for this. It is for our up
and down lines, but what about our 45's or horizontals where we do indeed have
lift on the low aileron and drag on the other? This would create a different
condition I'm guessing.. Probably small, but still a little different because
as I mention, both create drag on the up or downline.. Still, it's the best
test we have I guess.. <br>
> > <br>
> > Chris <br>
> > <br>
> > Lance Van Nostrand <patterndude@tx.rr.com> wrote:<br>
> > This thread is timely because I've been experimenting with
differential <br>
> > recently on a new design that seems to need it. Never needed it
before on a <br>
> > pattern plane but now I might. My test is to fly very high, point the
nose <br>
> > directly at the ground and roll pure aileron. Plane should be axial,
but <br>
> > remember that axial is along the vertical CG, which may not be a line
that <br>
> > pierces the wing LE/TE. You need to do it a few times to be sure that
their <br>
> > is an axis that everything rotates around and that line is straight.
If it <br>
> > wobbles, then we have an issue. Another way to determine this is to
do <br>
> > unlimited rolls while flying straight up. If the airplane
consistently arcs <br>
> > off its vertical line, you have a problem.<br>
> > <br>
> > Aerodynamics suggests two contributors. One is that the lowered
aileron <br>
> > increases the lift of the airfoil and lift creates drag so this wing
may <br>
> > pull the plane off axis. the other is that the spiral slipstream of
the prop <br>
> > is pushing down on the right wing and up on the left so up/right
aileron is <br>
> > more effective than up/left and down/left is more effective than
down/right.<br>
> > <br>
> > The overall effect for most pattern planes is minimal and usually
ignorable, <br>
> > but on IMAC style planes these factors can be significant and the
resulting <br>
> > differential corrections may need to be adjusted with something as
simple as <br>
> > a prop change (from 3 blade to 2 for example).<br>
> > <br>
> > the correction of course is to start playing with aileron
differential. <br>
> > Given the contributors I've suggested, its not a given which way you
go with <br>
> > the differential to correct the problem and the answer might not even
be <br>
> > symmetrical.<br>
> > <br>
> > Note that contributor #1 above will change if you are flying upright
or <br>
> > inverted, so it would seem that a correction for upright flight would
simply <br>
> > exacerbate inverted flight, but contributor #2 is the same for any
flight <br>
> > mode but is throttle dependent.<br>
> > <br>
> > --Lance<br>
> > <br>
> > ----- Original Message ----- <br>
> > From: "Koenig, Tom" <br>
> > To: "NSRCA Mailing List" <br>
> > Sent: Thursday, March 06, 2008 4:45 PM<br>
> > Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls<br>
> > <br>
> > <br>
> > > My head is spinning!!! The more I think about this, the more
questions I<br>
> > > have.........rather than answers!<br>
> > ><br>
> > > Maybe the contra rotating prop set up on a Voodoo X( Nat??)
maybe the<br>
> > > answer??<br>
> > ><br>
> > > I still 'feel', that the best rolls I get are with a 0
differential set<br>
> > > up-BUT- somehow I 'drive' that wing to 0 ( or should that be
some sort<br>
> > > of equilibrium??) during the rolls. Certainly in my case, it
seems to be<br>
> > > Pilot dependant!!!<br>
> > > I'm starting to think that my rudder control has turned to the<br>
> > > proverbial trying to micro analyse what's happening!<br>
> > ><br>
> > > Tom<br>
> > ><br>
> > > -----Original Message-----<br>
> > > From: nsrca-discussion-bounces@lists.nsrca.org<br>
> > > [mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of<br>
> > > shinden1@cox.net<br>
> > > Sent: Friday, 7 March 2008 9:15 AM<br>
> > > To: NSRCA Mailing List<br>
> > > Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls<br>
> > ><br>
> > > what happens on a 4piont?<br>
> > > Bryan<br>
> > > ---- Del Rykert wrote:<br>
> > >> The general consensus has been that the faster moving
molecules over<br>
> > > the top surface don't require as big as a deflection as the
aileron that<br>
> > > deflects towards the bottom of the plane. What one tries to
achieve is<br>
> > > the plane tracks as purely straight on a string as possible
while one<br>
> > > rolls both directions without introducing any yaw.<br>
> > >><br>
> > >> Del<br>
> > >><br>
> > >> ----- Original Message -----<br>
> > >> From: <br>
> > >> To: "NSRCA Mailing List" <br>
> > >> Sent: Thursday, March 06, 2008 2:49 PM<br>
> > >> Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls<br>
> > >><br>
> > >><br>
> > >> > Nat and all you other aerodynamicists,<br>
> > >> ><br>
> > >> > I thought that the rational for "aileron
differential" was that<br>
> > > upward deflection causes more drag than downward deflection so
to<br>
> > > equalize drag and prevent yaw with aileron deflection, aileron<br>
> > > differential is needed. It seems that you guys are now saying
that<br>
> > > ain't so. Please elaborate.<br>
> > >> ><br>
> > >> > George<br>
> > >> ><br>
> > >> > ---- Nat Penton wrote:<br>
> > >> ><br>
> > >> > =============<br>
> > >> > IMO center hinged or top hinged is OK. With top hinge,
to achieve<br>
> > > equal vertical travel of the trailing edge requires different
angular<br>
> > > travel, up vs down. The objective is zero aerodynamic
differential.<br>
> > >> ><br>
> > >> > Ron I don't think a fairing would prevent separation
but, how are<br>
> > > you able to fair the gap using the top hinge ? Nat<br>
> > >> > ----- Original Message -----<br>
> > >> > From: ronlock@comcast.net<br>
> > >> > To: NSRCA Mailing List<br>
> > >> > Sent: Thursday, March 06, 2008 7:20 AM<br>
> > >> > Subject: Re: [NSRCA-discussion] YS Questions+more -
Rolls<br>
> > >> ><br>
> > >> ><br>
> > >> > And while your at it, I'd appreciate some discussion of
the impact<br>
> > > of the top hinge system as seen on Viavat, and Prestige birds -
(top<br>
> > > hinged, with fairing that eliminates the gap at deflection)<br>
> > >> ><br>
> > >> > Thanks, Ron Lockhart<br>
> > >> ><br>
> > >> > -------------- Original message -------------- <br>
> > >> > From: vicenterc@comcast.net<br>
> > >> ><br>
> > >> > Nat,<br>
> > >> ><br>
> > >> > Could you explain why the differential should be
different for<br>
> > > non-center hinged? I understand that the mechanical
configuration of<br>
> > > non-center hinged requires differential to obtain same travel in
both<br>
> > > directions. However, the travel up and down should be close to
equal.<br>
> > >> ><br>
> > >> > Thanks,<br>
> > >> ><br>
> > >> > --<br>
> > >> > Vicente "Vince" Bortone<br>
> > >> ><br>
> > >> > -------------- Original message -------------- <br>
> > >> > From: "Nat Penton" <br>
> > >> ><br>
> > >> > Tom<br>
> > >> > It's just something that is peculiar to the Southern<br>
> > > Hemisphere.<br>
> > >> ><br>
> > >> > Changing wing incidence will not help. Unless things
are really<br>
> > > screwed up , at our roll rates, centrifugal forces are too low
to<br>
> > > cause a problem. You want zero differential, aero speaking (
same<br>
> > > up/down if center hinged ).<br>
> > >> ><br>
> > >> > I find the best check is the fast half-roll in the
vertical up.<br>
> > > Regards Nat<br>
> > >> > ----- Original Message ----- <br>
> > >> > From: Koenig, Tom<br>
> > >> > To: NSRCA Mailing List<br>
> > >> > Sent: Wednesday, March 05, 2008 7:24 PM<br>
> > >> > Subject: Re: [NSRCA-discussion] YS Questions+more<br>
> > >> ><br>
> > >> ><br>
> > >> > Hi Troy!<br>
> > >> ><br>
> > >> > Thanks for the info. I thought you would be toiling
away on<br>
> > > the next developmental stage of these engines!!<br>
> > >> ><br>
> > >> > Hopefully soon, I can find the time to get flying
again. I am<br>
> > > looking forward to running this little beast. I am still a
little<br>
> > > concerned in keeping it quiet though.<br>
> > >> ><br>
> > >> > Four blade props? I have some of the 18.1 x 12 two
bladers<br>
> > > but I just cant see how I'll shut the thing up with these paint<br>
> > > stirrers??<br>
> > >> ><br>
> > >> > Also-one more question to any of you out there in
pattern<br>
> > > land.<br>
> > >> ><br>
> > >> > I have struggled with aileron differential for years. I
am<br>
> > > just not happy with the rolls. I have tried various design
fixes-but<br>
> > > about the only one that seems to work is to get the wing back to
0-0 (<br>
> > > which can be achieved by a few ways, design, mix or thumbs)
Differential<br>
> > > itself does not seem to work if the wing is POA ( well...it
works for<br>
> > > half the roll !)<br>
> > >> > Another black magic fix appears to be to run parallel<br>
> > > ailerons-but this only 'sorta' seems to fix it. I like the feel
of<br>
> > > equal% chord ailerons however.<br>
> > >> ><br>
> > >> > I am frustrated with it-I like my planes to roll as if
they<br>
> > > had a string up its ...........well you know!<br>
> > >> ><br>
> > >> > OK-any 'secrets' I need to know??? Very good elevator
work<br>
> > >> > fixes it ( hence my 0-0 comment)<br>
> > >> ><br>
> > >> > Tom<br>
> > >> ><br>
> > >> ><br>
> > >> >
--------------------------------------------------------------------<br>
> > >> > ----<br>
> > >> ><br>
> > >> ><br>
> > >> > _______________________________________________<br>
> > >> > NSRCA-discussion mailing list<br>
> > >> > NSRCA-discussion@lists.nsrca.org<br>
> > >> >
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>
> > >> ><br>
> > >> ><br>
> > >> > --------------------------------------------------------------------<br>
> > >> > ----------<br>
> > >> ><br>
> > >> ><br>
> > >> > _______________________________________________<br>
> > >> > NSRCA-discussion mailing list<br>
> > >> > NSRCA-discussion@lists.nsrca.org<br>
> > >> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>
> > >> > _______________________________________________<br>
> > >> > NSRCA-discussion mailing list<br>
> > >> > NSRCA-discussion@lists.nsrca.org<br>
> > >> >
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>
> > >> ><br>
> > ><br>
> > > _______________________________________________<br>
> > > NSRCA-discussion mailing list<br>
> > > NSRCA-discussion@lists.nsrca.org<br>
> > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>
> > > _______________________________________________<br>
> > > NSRCA-discussion mailing list<br>
> > > NSRCA-discussion@lists.nsrca.org<br>
> > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion <br>
> > <br>
> > _______________________________________________<br>
> > NSRCA-discussion mailing list<br>
> > NSRCA-discussion@lists.nsrca.org<br>
> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>
> > <br>
> > <br>
> > <br>
> > Chris <br>
> > <br>
> > <br>
> > <br>
> > <br>
> > <br>
> > ---------------------------------<br>
> > Never miss a thing. Make Yahoo your homepage.<br>
> _______________________________________________<br>
> NSRCA-discussion mailing list<br>
> NSRCA-discussion@lists.nsrca.org<br>
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