X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 02 Jul 2011 01:23:20 -0400 Message-ID: X-Original-Return-Path: Received: from nm15-vm0.bullet.mail.ac4.yahoo.com ([98.139.52.236] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with SMTP id 5039809 for lml@lancaironline.net; Fri, 01 Jul 2011 13:32:51 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.52.236; envelope-from=airmale4@yahoo.com Received: from [98.139.52.197] by nm15.bullet.mail.ac4.yahoo.com with NNFMP; 01 Jul 2011 17:32:15 -0000 Received: from [98.139.52.136] by tm10.bullet.mail.ac4.yahoo.com with NNFMP; 01 Jul 2011 17:32:15 -0000 Received: from [127.0.0.1] by omp1019.mail.ac4.yahoo.com with NNFMP; 01 Jul 2011 17:32:15 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 634350.95300.bm@omp1019.mail.ac4.yahoo.com Received: (qmail 93806 invoked by uid 60001); 1 Jul 2011 17:32:15 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=Zev0gFLS7fdaP59EeptCvkU/LJQLrHX12m1crUQkmvogca9n+h3xeYWPoqDkuaIJ+utAKApHd4lXJ5Lsxe8IxGClx74NhoTJcol5IxvlsMMoy02LS+vmaRTKaWel/vFlkEBEUyyCMWhJePoGy5yxQKaq3rKrKqAm94K+0kw/krI=; X-YMail-OSG: oLsayIsVM1knX0rkmrT.uQAio3paBs4acosu8NIwcaR9xoQ ZUmJV60DTTymBF7aCBg7SUWOd9tSjBla7DTXouzYCaH74Svc1b8YQPXYQdrK icJuC_IB_24CT9V4WZ0Lud1auFvlniARy74I8fVpL37SoWhG7I7f6Hyq4bV9 JXZWs53gyUC1ymffEAZ52e9driEhuJ89PRYLKm4aGvtFcAX7KKFWUWEQuN5H 4tvrDwn9BEx3oxQ6ejuAK7wo4CL3xZhp3PZsNt6QHhz.rRF2hVWQAjtqC_AI lqIca4Z2sCdiAlYRF8EwMk_depnE7eGcu.iIKXDr1IzUgcbW1tbvPwrnIp5n mAS.vhGCKnPVbdnX92.Qt4YxKpWUx8aOBj2uh7qE9dnTjeOXEFxsD.OnjkaX 8urdTrw0iTt97Iw-- Received: from [75.88.115.239] by web65817.mail.ac4.yahoo.com via HTTP; Fri, 01 Jul 2011 10:32:15 PDT X-Mailer: YahooMailWebService/0.8.112.307740 References: X-Original-Message-ID: <1309541535.93341.YahooMailNeo@web65817.mail.ac4.yahoo.com> X-Original-Date: Fri, 1 Jul 2011 10:32:15 -0700 (PDT) From: J H Webb Reply-To: J H Webb Subject: Re: [LML] Re: Ventral Strakes, do they reduce performance? X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1219639460-1309541535=:93341" --0-1219639460-1309541535=:93341 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable I second Jeff's comment that a yaw damper is not really necessary on the LI= V P. Although it would be an improvement for a LIV PT. A true high frequenc= y yaw damper that did not move the rudder petals would improve the ride in = turbulence but none are available for GA.=C2=A0=0A=0AJack Webb=0AL360, LIV = =0AAeroSpace Engineer BSAE =0AFAA Designated Check airman for C421, C404 & = C310=0AATP, CFI Airplanes & Instruments, Multi, & Sea=0ANumerous Jet Type R= atings=0AExperienced Experimental Test Pilot both multi and single engine a= ircraft=0AFormer Chief Engineering Test Pilot for a Major Manufacturer=0AOh= io=0A=0A=0A________________________________=0AFrom: "vtailjeff@aol.com" =0ATo: lml@lancaironline.net=0ASent: Friday, July 1, 2011 7= :45 AM=0ASubject: [LML] Re: Ventral Strakes, do they reduce performance?=0A= =0A=0AYou do not need a yaw damper in the IVP.=0A=0AJeff=0A=0ASent from my = iPad=0A=0AOn Jun 30, 2011, at 6:10 PM, Ronald STEVENS wrot= e:=0A=0A=0AHi Jack=0A>=0A>=0A>Thanks for the explanations, I have the Tru-T= rak sorcerer installed in my plane and was planning the Yaw damper as it is= said that the 4p changes yaw with every speed change, so I am assuming the= yaw damper together with the auto trim would correct this issue, right?=0A= >=0A>=0A>=3D=3D Ronald=0A>=0A>From: J H Webb =0A>Reply= -To: Lancair Mailing List =0A>Date: Thu, 30 Jun 20= 11 15:06:20 -0400=0A>To: =0A>Subject: [LML] Re: Ve= ntral Strakes, do they reduce performance?=0A>=0A>=0A>=0A>Ron,=0A>=0A>=0A>= =C2=A0=C2=A0=C2=A0 Sorry it has taken so long but I have been busy. You hav= e asked several questions, and on the question of Ventral fins, I have had = installed Ventral fins on several LIV's. The need is much greater for the L= IV-PT but there is an improvement in both piston and turbine models. The li= ttle dual fins are not as effective as one larger single fin. Plus the drag= seems to be lower. I have designed a single fin shape that works well, no = noticeable impact on cruise speed.=0A>I did notice a slight speed reduction= with the twin Ventral fin taht are used on several LIV-PT's.=0A>=C2=A0 Cla= rk Still's aircraft is a good example of a PT with the single fin Ventral f= in, on that airplane we made a very significant improvement in directional = stability.=0A>=C2=A0=C2=A0=C2=A0=C2=A0 On the question about yaw dampers, t= he yaw damper is very helpful when it is a high frequency unit with no feed= back in the rudders. Unfortunately hte yaw dampers available currently are = on limited value plus the current units that connect directly to the rudder= increase the rudder friction band significantly making the airplane more d= ifficult to master yaw control. The ideal installation would a unit operati= ng a separate control surface such as the trailing edge of the ventral fin.= =0A>=0A>=0A>Jack Webb=0A>L360, LIV =0A>AeroSpace Engineer BSAE =0A>FAA Desi= gnated Check airman for C421, C404 & C310=0A>ATP, CFI Airplanes & Instrumen= ts, Multi, & Sea=0A>Numerous Jet Type Ratings=0A>Experienced Experimental T= est Pilot both multi and single engine aircraft=0A>Former Chief Engineering= Test Pilot for a Major Manufacturer=0A>Corporate Chief Pilot for Construct= ion=0Acompany=0A>Ohio=0A>=0A>=0A>Flying is the perfect vocation=0Afor a man= who wants to feel like a boy, but not for one who still is.=0A>=0A>=0A>=0A= >________________________________=0A>From: RONALD STEVENS = =0A>To: lml@lancaironline.net=0A>Sent: Monday, June 27, 2011 7:34 AM=0A>Sub= ject: [LML] Ventral Strakes, do they reduce performance?=0A>=0A>=0A>Hello g= uys=0A>=0A>=0A>Me again, I just had my first lesson with the Lancair 4p (wi= th JC) and when I took off the plane was wiggling its tail like a happy dog= LOL Nothing scary, but this I can imagine could be annoying for passengers= .=0A>=0A>=0A>Now I was looking on the internet and found that=C2=A0Ventral = Strakes =C2=A0were used to fight against those 'yaw' effects.=0A>It suppose= to help with turbulence, go-arrounds, full power take offs as well.=0A>=0A= >=0A>My very near future plane (we are almost closing ;) is a newer one, so= the tail section was already updated to the latest.=C2=A0=0A>=0A>=0A>But l= ooking at my passengers (I fly with my Son and Girlfriend a lot) this could= be disturbing for them and I was already thinking of installing the Yaw da= mper (I have the tru-trak sorcerer) and perhaps also installing those Ventr= al strakes.=0A>=0A>=0A>Does anybody have experience (before and after) with= those? And would you recommend those?=C2=A0=0A>=0A>=0A>Thanks =E2=80=94 Ro= nald Stevens (Cirrus 1100 hours, Velocity 250 hours, Lancair 4p student now= with 1 hour LOL)=0A>=0A> --0-1219639460-1309541535=:93341 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
I second Jeff's com= ment that a yaw damper is not really necessary on the LIV P. Although it wo= uld be an improvement for a LIV PT. A true high frequency yaw damper that d= id not move the rudder petals would improve the ride in turbulence but none= are available for GA. 

<= !--[if gte mso 9]>=0A =0A Normal=0A = 0=0A =0A =0A =0A =0A f= alse=0A false=0A false= =0A =0A EN-US=0A <= w:LidThemeAsian>X-NONE=0A X-NON= E=0A =0A =0A =0A =0A =0A =0A =0A= =0A = =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A