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 blu0-omc3-s5.blu0.hotmail.com ([65.55.116.80] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTP id 5039151 for lml@lancaironline.net; Thu, 30 Jun 2011 23:56:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.55.116.80; envelope-from=cgainza@msn.com Received: from BLU139-W35 ([65.55.116.74]) by blu0-omc3-s5.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Thu, 30 Jun 2011 20:56:16 -0700 X-Original-Message-ID: X-Original-Return-Path: cgainza@msn.com Content-Type: multipart/alternative; boundary="_6d1d9e9f-e4e6-4873-b915-223f14003bad_" X-Originating-IP: [24.5.212.73] From: Craig Gainza X-Original-To: list lancair Subject: RE: [LML] Re: Ventral Strakes, do they reduce performance? X-Original-Date: Thu, 30 Jun 2011 20:56:16 -0700 Importance: Normal In-Reply-To: References: MIME-Version: 1.0 X-OriginalArrivalTime: 01 Jul 2011 03:56:16.0638 (UTC) FILETIME=[D3E8C9E0:01CC37A2] --_6d1d9e9f-e4e6-4873-b915-223f14003bad_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Colyn=2C I have not experienced the nauseating wig wag in or out of turbulence. I w= ould be interested in how many IV-P pilots have "nauseating wig-wag" that n= eeds to be addressed. =20 I do know many IV-P vertical stabs are not straight. After building my IV-= P by the book=2C I found that the vertical was canted 3.5" to the starboar= d side. It was then rebuilt so the tail was straight. I know other builde= rs that also found and corrected this deficiency. Is this playing a role? = I don't know. I am certainly interested in what others have experienced. Craig To: lml@lancaironline.net Date: Thu=2C 30 Jun 2011 15:06:20 -0400 From: colyncase@earthlink.net Subject: [LML] Re: Ventral Strakes=2C do they reduce performance? Craig=2C I may end up in the same place. There are certain turbulence conditions = where you get kind of a nauseating periodic wig-wag. It would be nice if = the yaw damper would help with that.=20 Colyn On Jun 30=2C 2011=2C at 7:51 AM=2C Craig Gainza wrote:Ron and Colyn=2C After almost 800 hours on our piston IV-P (many with back seat passengers) = my bigger concern would be the added weight in back. My opinion is that st= rakes and yaw dampers add unneeded aft weight. Ron=2C I think you will fee= l comfortable with the yaw stability after a few more lessons. =20 I have not had any complaints from back seat. After similar yaw damper issues as Colyn=2C Tim Ong suggested I remove my y= aw damper. I removed it after year one and never missed it. Craig Gainza To: lml@lancaironline.net Date: Wed=2C 29 Jun 2011 07:34:46 -0400 From: colyncase@earthlink.net Subject: [LML] Re: Ventral Strakes=2C do they reduce performance? Ronald=2C I had the Mike Custard ventrals and I have to say the plane was quite stabl= e in yaw. e.g. better than a Mooney Rocket.However=2C I also flew N409L i= n training which is a straight IV and didn't notice any big problem with ya= w stability.That said=2C I road in another IVP back seat on a bumpy (therma= ls ) day and didn't like the ride at all. Not sure if it was the pilotor t= he airplane. I am unable to say if the Mike Custard ventrals add a lot more drag as I ne= ver flew my plane without them. You might want to get some aerodynamic an= alysis if you go that route. Mike's fins were definitely designed to solv= e a real problem with the turbines so if an argument could be made that ven= trals have any use on a piston it could probably also be made that those bi= g dual fins are overkill. I think I agree with Bob that you don't need a ventral fin for cruise comfo= rt.My interest in them was somewhat speculative and in relation to stalls. = The thought was that the vstab is largely blanketed by the wing at high a= ngles of attack so that a ventral fin might be more effective for avoiding = a yaw departure. I will probably never know the answer to that but I will= note that the Columbia 400 has a ventral fin. As far as the yaw damper goes. I have a Sorcerer with the yaw damper. So = far i haven't got it do anything useful in turbulence. I'm still working = with Tru-Trak on that. Colyn On Jun 27=2C 2011=2C at 7:34 AM=2C RONALD STEVENS wrote:Hello guys Me again=2C I just had my first lesson with the Lancair 4p (with JC) and wh= en I took off the plane was wiggling its tail like a happy dog LOL Nothing = scary=2C but this I can imagine could be annoying for passengers. Now I was looking on the internet and found that Ventral Strakes were used= to fight against those 'yaw' effects.It suppose to help with turbulence=2C= go-arrounds=2C full power take offs as well. My very near future plane (we are almost closing =3B) is a newer one=2C so = the tail section was already updated to the latest.=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 = Ventral strakes. Does anybody have experience (before and after) with those? And would you r= ecommend those?=20 Thanks =97 Ronald Stevens (Cirrus 1100 hours=2C Velocity 250 hours=2C Lanca= ir 4p student now with 1 hour LOL) = --_6d1d9e9f-e4e6-4873-b915-223f14003bad_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Colyn=2C

I have not experienced the nauseating wig wag in or out of = turbulence. =3B I would be interested in how many IV-P pilots have "nau= seating wig-wag" that needs to be addressed. =3B

I do know many= IV-P vertical stabs are not straight. =3B After building my IV-P by th= e book=2C I found that the vertical =3B was canted 3.5" to the starboar= d side. =3B It was then rebuilt so the tail was straight. =3B I kno= w other builders that also found and corrected this deficiency. =3B Is = this playing a role? =3B I don't know.

I am certainly interested= in what others have experienced.

Craig



To: lml@lancaironline.net
Date: Thu=2C 30 Jun 2011 15:= 06:20 -0400
From: colyncase@earthlink.net
Subject: [LML] Re: Ventral = Strakes=2C do they reduce performance?

Craig=2C

I may end up in the same place.  =3B  =3BThere are certain= turbulence conditions where you get kind of a nauseating periodic wig-wag.=  =3B It would be nice if the yaw damper would help with that. =3B<= /div>

Colyn

On Jun 30=2C 2011=2C= at 7:51 AM=2C Craig Gainza wrote:

Ron and Colyn= =2C

After almost 800 hours on our piston IV-P (many with back seat p= assengers) my bigger concern would be the added weight in back. =3B My = opinion is that strakes and yaw dampers add unneeded aft weight. =3B Ro= n=2C I think you will feel comfortable with the yaw stability after a few m= ore lessons. =3B =3B

I have not had any complaints from back seat.

After similar= yaw damper issues as Colyn=2C Tim Ong suggested I remove my yaw damper.&nb= sp=3B I removed it after year one and never missed it.

Craig Gainza<= br>




To: lml@lancaironline.net
Date: Wed=2C 29 Jun 2= 011 07:34:46 -0400
From: = =3Bcolyncase@earthlink.ne= t
Subject: [LML] Re: Ventral Strakes=2C do they reduce performance?<= br>
Ronald=2C

I had the Mike Custard ventrals and I h= ave to say the plane was quite stable in yaw.  =3B e.g. better than a M= ooney Rocket.
However=2C I also flew N409L in training which is a= straight IV and didn't notice any big problem with yaw stability.
That said=2C I road in another IVP back seat on a bumpy (thermals ) day a= nd didn't like the ride at all.  =3BNot sure if it was the pilot
<= div>or the airplane.

I am unable to say if the Mik= e Custard ventrals add a lot more drag as I never flew my plane without the= m.  =3B You might want to get some aerodynamic analysis if you go that = route.  =3B Mike's fins were definitely designed to solve a real proble= m with the turbines so if an argument could be made that ventrals have any = use on a piston it could probably also be made that those big dual fins are= overkill.

I think I agree with Bob that you don't= need a ventral fin for cruise comfort.
My interest in them was s= omewhat speculative and in relation to stalls.  =3B The thought was tha= t the vstab is largely blanketed by the wing at high angles of attack so th= at a ventral fin might be more effective for avoiding a yaw departure. &nbs= p=3B I will probably never know the answer to that but I will note that the= Columbia 400 has a ventral fin.

As far as the yaw= damper goes. I have a Sorcerer with the yaw damper.  =3B So far i have= n't got it do anything useful in turbulence.  =3B I'm still working wit= h Tru-Trak on that.

Colyn

On Jun 27=2C 2011=2C at 7:34 AM=2C RONALD STEVENS wrote:
Hello guys

Me again=2C I jus= t had my first lesson with the Lancair 4p (with JC) and when I took off the= plane was wiggling its tail like a happy dog LOL Nothing scary=2C but this= I can imagine could be annoying for passengers.

N= ow I was looking on the internet and found that =3BVentral Stra= kes =3B = =3Bwere used to fight against those 'yaw' effects.
It suppose to = help with turbulence=2C go-arrounds=2C full power take offs as well.
<= div>
My very near future plane (we are almost closing =3B) is= a newer one=2C so the tail section was already updated to the latest. = =3B

But looking at my passengers (I fly with my So= n and Girlfriend a lot) this could be disturbing for them and I was already= thinking of installing the Yaw damper (I have the tru-trak sorcerer) and p= erhaps also installing those Ventral strakes.

Does= anybody have experience (before and after) with those? And would you recom= mend those? =3B

Thanks =97 Ronald Stevens (Cir= rus 1100 hours=2C Velocity 250 hours=2C Lancair 4p student now with 1 hour = LOL)



= = --_6d1d9e9f-e4e6-4873-b915-223f14003bad_--