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<DIV>Ray....you just described Nat's plane....I think there is a picture
of one of his planes in one of the early issues of 3d flyer...they
interviewed Nat.</DIV>
<DIV> </DIV>
<DIV>-mark</DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=pizzaalt@concentric.net href="mailto:pizzaalt@concentric.net">ray
ayestaran</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, January 01, 2005 9:32
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Next revolution in pattern
planes?</DIV>
<DIV><BR></DIV>
<DIV>does anyone have a Hanno Prettner article or articles describing
research/development for curare and its anhedral stab? I remember at
that time pattern contests were won and lost with loops which require
just the right amount of rudder at the right time to keep them round, constant
speed and not to loose heading upon completion was a big downgrade.
Hanno understood that the spiraling airstream from prop during straight and
level flight bombards the tail group at a certain angle with maximum
force pushing the nose to the left. right engine thrust angle
is required to offset this. problem is right engine angle is fixed
in a compromised position. the amount of right thrust actually required
at any moment in time depends on throttle position, airspeed and angle of
attack. during positive loops the spiraling airstream is redirected away
from thrust line impacting only a small portion of top tail
post/rudder reducing left force but since right engine angle is
fixed you need some left rudder to hold your line. you can see where
this spiraling airstream is being directed by flying slow with smoke
on. during an outside loop prop air is directed away from thrustline
past out and away past bottom of airplane where no tail group exists -
now you need even more left rudder to hold your line. lets fix the
problem:</DIV>
<DIV> </DIV>
<DIV>1. you can have as much tail group area below thrustline as above - prop
airstream would push plane to right and left with the same force
canceling this effect - plane would look funny and require extra long landing
gear.</DIV>
<DIV>2. you can put in some fixed rudder trim or mix throttle to
rudder but this doesn't address airspeed/angle of attack problems listed above
only engine thrust.</DIV>
<DIV>3. you can chop off the top of tailpost/rudder (less
tail area above thrustline for prop air to impact)
you can drop down or flair out the bottom of tail group a few
inches (more tail area below thrustline to offset area above) you
can also put in some stab anhedral which adds tailgroup below
thrustline and takes away from above. now add some more side area to fuse
and especially in front of cg to setup a nice rudder pivot point and get
back rudder authority you just cut away from top of tail and you have a
curare! you have not spoiled that "pattern look" the judges want and you
need only slight amount of right engine thrust offset. nothing loops better
than a curare, only a handful of pilots with expert rudder skill can beat
a curare with something else. pattern contests might be won with straight
lines but more points are deducted in half loops/loops, snaps, looping
maneuvers, etc. loosing your heading on the backside of a looping
maneuver or snap effects that manuever and the next. just my 2 cents -
sorry for long post. </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=Rcmaster199@aol.com
href="mailto:Rcmaster199@aol.com">Rcmaster199@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, December 31, 2004 7:35
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Next revolution in pattern
planes?</DIV>
<DIV><BR></DIV><FONT id=role_document face=Arial color=#000000 size=2>
<DIV>
<DIV>Anhedral stabs are affected by crosswind more than flat stabs. At least
for the kind of flying we demand. The Prettner Curare design, World Champ
around 1976 or so, introduced the feature to models. By virtue of its being
World Champion model, everybody copied it. Sort of the way fixed gear took
over from retracts, except fixed gear have persisted far longer and serve
the intended purpose well. </DIV>
<DIV> </DIV>
<DIV>Curares and other anhedral stab designs flew well into the 80's but
eventually the fad died down. </DIV>
<DIV> </DIV>
<DIV>Naruke san is possibly trying to cure some aerodynamic inadequacy by
employing the feature again. Or maybe just likes the look. It does look Kool
as hell. I doubt that this is a revolution though; more like evolution....in
reverse</DIV>
<DIV> </DIV>
<DIV>MattK</DIV>
<DIV> </DIV>
<DIV>In a message dated 12/31/2004 6:54:03 PM Eastern Standard Time,
rcaerobob@cox.net writes:</DIV>
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style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
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<DIV><FONT face=Arial size=2>Beautiful plane, but planform is BTDT,
remember Hanno??? And the Bridi UFO? And others. The anhedral
stab really introduce bizarre characteristics, if I recall. It was
abandoned as an "innovation" about as fast as *somebody's* "Split Rudder
"airbrake"....</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Man, we are O-L-D...</FONT></DIV>
<DIV><BR>Bob Pastorello<BR>NSRCA 199 AMA 46373<BR><A
title=mailto:rcaerobob@cox.net
href="mailto:rcaerobob@cox.net">rcaerobob@cox.net</A><BR><A
title=http://www.rcaerobats.net/
href="http://www.rcaerobats.net/">www.rcaerobats.net</A></DIV>
<DIV> </DIV>
<DIV> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=mailto:adam.g@sasktel.net href="mailto:adam.g@sasktel.net">Adam
Glatt</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, December 31, 2004
4:54 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Next revolution in pattern
planes?</DIV></BLOCKQUOTE></FONT></BLOCKQUOTE></DIV>
<DIV></DIV>
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