X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 01 Jul 2011 07:45:55 -0400 Message-ID: X-Original-Return-Path: Received: from imr-ma04.mx.aol.com ([64.12.206.42] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTP id 5039190 for lml@lancaironline.net; Fri, 01 Jul 2011 01:37:20 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.42; envelope-from=vtailjeff@aol.com Received: from mtaout-db02.r1000.mx.aol.com (mtaout-db02.r1000.mx.aol.com [172.29.51.194]) by imr-ma04.mx.aol.com (8.14.1/8.14.1) with ESMTP id p615af1J000921 for ; Fri, 1 Jul 2011 01:36:41 -0400 Received: from [192.168.1.149] (24-107-65-42.dhcp.stls.mo.charter.com [24.107.65.42]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mtaout-db02.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id 6EB67E0000C0; Fri, 1 Jul 2011 01:36:39 -0400 (EDT) References: In-Reply-To: Mime-Version: 1.0 (iPad Mail 8C148) Content-Type: multipart/alternative; boundary=Apple-Mail-4-478919582 X-Original-Message-Id: <00FA9F29-2D47-4B1A-A33E-DCD6BBDC783F@aol.com> Content-Transfer-Encoding: 7bit X-Mailer: iPad Mail (8C148) From: vtailjeff@aol.com Subject: Re: [LML] Re: Ventral Strakes, do they reduce performance? X-Original-Date: Fri, 1 Jul 2011 00:36:38 -0500 X-Original-To: Lancair Mailing List x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:466586944:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33c24e0d5ce703da X-AOL-IP: 24.107.65.42 --Apple-Mail-4-478919582 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 You do not need a yaw damper in the IVP. Jeff Sent from my iPad On Jun 30, 2011, at 6:10 PM, Ronald STEVENS wrote: > Hi Jack >=20 > Thanks for the explanations, I have the Tru-Trak sorcerer installed in my p= lane and was planning the Yaw damper as it is said that the 4p changes yaw w= ith every speed change, so I am assuming the yaw damper together with the au= to trim would correct this issue, right? >=20 > =3D=3D Ronald >=20 > From: J H Webb > Reply-To: Lancair Mailing List > Date: Thu, 30 Jun 2011 15:06:20 -0400 > To: > Subject: [LML] Re: Ventral Strakes, do they reduce performance? >=20 > Ron, >=20 > Sorry it has taken so long but I have been busy. You have asked severa= l questions, and on the question of Ventral fins, I have had installed Ventr= al fins on several LIV's. The need is much greater for the LIV-PT but there i= s an improvement in both piston and turbine models. The little 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. > I did notice a slight speed reduction with the twin Ventral fin taht are u= sed on several LIV-PT's. > Clark Still's aircraft is a good example of a PT with the single fin Ven= tral fin, on that airplane we made a very significant improvement in directi= onal stability. > On the question about yaw dampers, the yaw damper is very helpful whe= n it is a high frequency unit with no feedback in the rudders. Unfortunately= hte yaw dampers available currently are on limited value plus the current u= nits that connect directly to the rudder increase the rudder friction band s= ignificantly making the airplane more difficult to master yaw control. The i= deal installation would a unit operating a separate control surface such as t= he trailing edge of the ventral fin. >=20 > Jack Webb > L360, LIV > AeroSpace Engineer BSAE=20 > 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 > Corporate Chief Pilot for Construction company > Ohio >=20 > Flying is the perfect vocation for a man who wants to feel like a boy, but= not for one who still is. >=20 > From: RONALD STEVENS > To: lml@lancaironline.net > Sent: Monday, June 27, 2011 7:34 AM > Subject: [LML] Ventral Strakes, do they reduce performance? >=20 > Hello guys >=20 > Me again, I just had my first lesson with the Lancair 4p (with JC) and whe= n I took off the plane was wiggling its tail like a happy dog LOL Nothing sc= ary, but this I can imagine could be annoying for passengers. >=20 > Now I was looking on the internet and found that Ventral Strakes were use= d to fight against those 'yaw' effects. > It suppose to help with turbulence, go-arrounds, full power take offs as w= ell. >=20 > My very near future plane (we are almost closing ;) is a newer one, so the= tail section was already updated to the latest.=20 >=20 > But looking 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 Y= aw damper (I have the tru-trak sorcerer) and perhaps also installing those V= entral strakes. >=20 > Does anybody have experience (before and after) with those? And would you r= ecommend those?=20 >=20 > Thanks =E2=80=94 Ronald Stevens (Cirrus 1100 hours, Velocity 250 hours, La= ncair 4p student now with 1 hour LOL) >=20 >=20 --Apple-Mail-4-478919582 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
You do not need a yaw damper in the IVP= .

Jeff

Sent from my iPad

On Ju= n 30, 2011, at 6:10 PM, Ronald STEVENS <Ronald@sdc.com> wrote:

Hi Jack

Thanks for the explanations,= I have the Tru-Trak sorcerer installed in my plane and was planning t= he 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 co= rrect this issue, right?

=3D=3D Ronald
From: J H Webb <airmale= 4@yahoo.com>
Reply-To: Lancair Mailing List <lml@lancaironline.net>
Date: Thu, 30 Jun 2011 15:06:20 -0400
To: <lml@lancaironline.net>
Subject: [LML] Re: Ve= ntral Strakes, do they reduce performance?

Ron,

=
    Sorry it has taken so long but I h= ave been busy. You have asked several questions, and on the question of Vent= ral fins, I have had installed Ventral fins on several LIV's. The need is mu= ch greater for the LIV-PT but there is an improvement in both piston and tur= bine models. The little dual fins are not as effective as one larger single f= in. Plus the drag seems to be lower. I have designed a single fin shape that= works well, no noticeable impact on cruise speed.
I d= id notice a slight speed reduction with the twin Ventral fin taht are used o= n several LIV-PT's.
  Clark Still's aircraft is a good= example of a PT with the single fin Ventral fin, on that airplane we made a= very significant improvement in directional stability.
     On the question about y= aw dampers, the yaw damper is very helpful when it is a high frequency unit w= ith no feedback in the rudders. Unfortunately hte yaw dampers available curr= ently are on limited value plus the current units that connect directly to t= he rudder increase the rudder friction band significantly making the airplan= e more difficult to master yaw control. The ideal installation would a unit o= perating a separate control surface such as the trailing edge of the ventral= fin.

Ja= ck 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
Corporate Chief Pil= ot for Construction company
Ohio

Fl= ying is the perfect vocation for a man who wants to feel like a boy, but not for one who still is.=

From: RONALD STEVENS <ronald@sdc.com>
To: lml@lancaironline.netSent: Monday, June 27, 20= 11 7:34 AM
Subject: [LML= ] Ventral Strakes, do they reduce performance?

Hello guys

Me again, I just had my f= irst lesson with the Lancair 4p (with JC) and when I took off the plane was w= iggling its tail like a happy dog LOL Nothing scary, but this I can imagine c= ould be annoying for passengers.

Now I was looking o= n the internet and found that Ventral Strakes  were used to= fight against those 'yaw' effects.
It suppose to help with turbul= ence, go-arrounds, full power take offs as well.

My= very near future plane (we are almost closing ;) is a newer one, so the tai= l section was already updated to the latest. 

= But looking at my passengers (I fly with my Son and Girlfriend a lot) this c= ould be disturbing for them and I was already thinking of installing the Yaw= damper (I have the tru-trak sorcerer) and perhaps also installing those Ven= tral strakes.

Does anybody have experience (before and a= fter) with those? And would you recommend those? 

<= div>Thanks =E2=80=94 Ronald Stevens (Cirrus 1100 hours, Velocity 250 hours, L= ancair 4p student now with 1 hour LOL)
=20


= --Apple-Mail-4-478919582--