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<DIV>Try a bit of upthrust, and if that causes a pitch to the belly w/ rudder, move the CG forward. Wouldn't be the first plane to need upthrust.</DIV>
<DIV><BR>Dave</DIV>
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<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">-------------- Original message -------------- <BR>From: <rcaerobob@cox.net> <BR>
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<P>With elev. trimmed for level upright flight (some Up trim), the downlines do NOT pitch (in fact, it drops about as straight as my best pattern plane ever has!). The trim anomaly SEEMS to be thrust-related, but since it's a non-adjustable wing/stab setup, my options are a little limited. </P>
<P>Thanks for the response! </P>
<P><BR>---- jivey61@bellsouth.net wrote:<BR>>Bob<BR>>I re-read your post and now think maybe you have negative incidence.This would cause you to carry up elev. trim and pull to canopy on power off lines. Do the power off down lines pull to the canopy also?<BR>><BR>>Jim Ivey<BR>>----- Original Message -----<BR>>From: Bob Pastorello<BR>>To: NSRCA Mailing List<BR>>Sent: Monday, May 22, 2006 6:53 AM<BR>>Subject: [NSRCA-discussion] Thrust Line Trimming<BR>><BR>><BR>>Hello - I have a BME 30% Yak, (and had a TOC/Aviation Models Yak), and both pitch to the canopy when power is reduced in vertical climbs (also on level cruise power deceleration, too). Elsewhere, fly well, and doesn't exhibit bizarre incidence problems, and both needed UP elev. trim for level upright flight.<BR>><BR>>ON the RCU threads on these two, owners report needing to carry up elev trim, also, but haven't gotten any insights on the engine thrust question.<BR>><BR>>I have
measured, and there is currently NO up or down thrust in the motor referenced to centerline.<BR>><BR>>Could these planes actually need some UP thrust??<BR>><BR>>Bob Pastorello<BR>>www.rcaerobats.net<BR>>rcaerobob@cox.net<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>Bob Pastorello, El Reno, OK, USA<BR>rcaerobob@cox.net<BR>www.rcaerobats.net<BR></P></DIV></BLOCKQUOTE></body></html>