X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 21 Oct 2008 21:17:19 -0400 Message-ID: X-Original-Return-Path: Received: from web55706.mail.re3.yahoo.com ([216.252.110.37] verified) by logan.com (CommuniGate Pro SMTP 5.2.9) with SMTP id 3232964 for lml@lancaironline.net; Tue, 21 Oct 2008 15:32:11 -0400 Received: (qmail 40581 invoked by uid 60001); 21 Oct 2008 19:32:08 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type:Message-ID; b=rrD6okdHEDPIJuvp1a2TETcRuWeGwAPRbi90ClaJ+ZDkfM1Gd57V5XLb3bEbLvYM45lYEQYVAofQ3n4C4gPC+45p1PjedqdAoEFZ050/b1mCubrsZWDdW4IUWCNt/YRklqZB2HooWQX/mR78KulJSSJQFbkE+AxdUelizGpk1rg=; X-YMail-OSG: ilS_IEIVM1myQMaJH4ZE82hjLXSa6ytW3.RQpn9CWLkxiiPrYXE4OmLZicjFueco6eNuGr6SNajamDt3Olt0cAEDOBoinICQ2Iv0iBUill..qP9nkZUcu9AGx.CfybJpCDwjC2o9GtYBGEzhwHr2QIKW2GvVTLwskG2f2ElKzOGrfZN5cIIyafoEFwBO Received: from [174.130.124.226] by web55706.mail.re3.yahoo.com via HTTP; Tue, 21 Oct 2008 12:32:08 PDT X-Mailer: YahooMailRC/1155.20 YahooMailWebService/0.7.247.3 X-Original-Date: Tue, 21 Oct 2008 12:32:08 -0700 (PDT) From: J H Webb Subject: Re: [LML] Yaw Damper in IVP X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1047702320-1224617528=:40225" X-Original-Message-ID: <580670.40225.qm@web55706.mail.re3.yahoo.com> --0-1047702320-1224617528=:40225 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable John, =0A=0AThe yaw damper adds friction to the rudder system and that fric= tion is very noticeable.=A0 It does reduce the tendency of the nose to chan= ge headings in flight but the need is low in the piston powered LIV's. The = turbine needs some additional fin aft of the center of gravity to assist in= power loss at high power low airspeed plus it is startling at high speed t= o see how much the nose yaws a an abrupt power loss or reduction.=A0 I have= used Ventral fins to address this and that produces a significant improvem= ent. =0A=0ATru Trak is a=A0wonderful autopilot but all of the servos have t= oo much friction with the servo unpowered. It makes it a little harder to f= eel the airplane.=0A=0AJack Webb=0AL360, LIV AeroSpace Engineer BSAE =0AFAA= Designated Check airman for C421, C404 & C310=0AATP, CFI Airplanes & Instr= uments, Multi, & Sea=0ANumerous Jet Type Ratings=0AExperienced Experimental= Test Pilot both multi and single engine aircraft=0AFormer Chief Engineerin= g Test Pilot for a Major Manufacturer=0A=0A=0A=0A=0A=0A____________________= ____________=0AFrom: John Barrett <2thman@cablespeed.com>=0ATo: lml@lancair= online.net=0ASent: Tuesday, October 21, 2008 1:07:27 AM=0ASubject: [LML] Ya= w Damper in IVP=0A=0AI'm interested to know about any experiences with Tru = Trak and yaw damper in=0Athe IVP.=A0 Is there a need to add auto trim?=A0 I= seem to recall reports that=0Awithout the yaw damper the aircraft gets a l= ittle unstable longitudinally,=0Abut can the yaw damper solve the problem o= n its own?=A0 =0A=0ARegards,=0A=0AJohn Barrett, CEO=0ALeading Edge Composit= es=0APO Box 428=0APort Hadlock, WA 98339=0Awww.carbinge.com=0A=A0 =0A=0A=0A= =0A=0A--=0AFor archives and unsub http://mail.lancaironline.net:81/lists/lm= l/List.html=0A=0A=0A=0A --0-1047702320-1224617528=:40225 Content-Type: text/html; charset=us-ascii

John,

The yaw damper adds friction to the rudder system and that friction is very noticeable. It does reduce the tendency of the nose to change headings in flight but the need is low in the piston powered LIV's. The turbine needs some additional fin aft of the center of gravity to assist in power loss at high power low airspeed plus it is startling at high speed to see how much the nose yaws a an abrupt power loss or reduction. I have used Ventral fins to address this and that produces a significant improvement.

Tru Trak is a wonderful autopilot but all of the servos have too much friction with the servo unpowered. It makes it a little harder to feel the airplane.

Jack Webb

L360, LIV

AeroSpace Engineer BSAE
FAA Designated Check airman for C421, C404 & C310
ATP, CFI Airplanes & Instruments, Multi, & Sea
Numerous Jet Type Ratings
Experienced Experimental Test Pilot both multi and single engine aircraft
Former Chief Engineering Test Pilot for a Major Manufacturer

From: John Barrett <2thman@cablespeed.com>
To: lml@lancaironline.net
Sent: Tuesday, October 21, 2008 1:07:27 AM
Subject: [LML] Yaw Damper in IVP

I'm interested to know about any experiences with Tru Trak and yaw damper in
the IVP. Is there a need to add auto trim? I seem to recall reports that
without the yaw damper the aircraft gets a little unstable longitudinally,
but can the yaw damper solve the problem on its own?

Regards,

John Barrett, CEO
Leading Edge Composites
PO Box 428
Port Hadlock, WA 98339
www.carbinge.com

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