REFLECTOR: sparrow strainer(ss)

Mon Nov 10 17:50:04 CST 2008

I had the difficult landing when my trim relay quit working.  It happened during descent
where I had the elevator trimmed up as far as it would go, so there was a lot of adverse
force when I had to pull back for the landing.  After reversing the SS I never use full trim,
so if it gets stuck again, it can't be as bad.  Also as you slow down, the effect of the SS
decreases, so it shouldn't be producing much force at landing.

Chuck, if your elevator is trimmed down (below the canard TE) at cruise, then you shouldn't
be out of up trim and there is no reason to reverse the SS.

John

Chuck Harbert wrote:

> I've had my ss installed per factory instructions, but I've now wondered if
> I should switch it to upside down based on some of the recent comments.
> However, I'm also concerned about losing the downward force if the trim
> spring were to break based upon a recent posting about how difficult it was
> to fly and land with it broken.
>
> I've got the usual V problem of having to have the elevator trimmed down
> about an inch at high speed, so if I flip it over will I have to trim it
> more to offset the upward force?  Has anyone tried this to see what happens?
>
> Chuck H
>
> ----- Original Message -----
> From: "Hiroo Umeno" ?humeno at microsoft.com?
> To: "Velocity Aircraft Owners and Builders list" ?reflector at tvbf.org?
> Sent: Monday, November 10, 2008 1:03 PM
> Subject: Re: REFLECTOR: amount of trim
>
> ? It was not me (though now that you mention it, seems like a great idea).
> ?
> ? I could probably embed a simple linear actuator inside the elevator to
> ? change the incidence angles of that thing and get rid of the fiberglass
> ? spring...
> ?
> ? Squirrels are running now.
> ?
> ? Hiroo
> ?
> ? -----Original Message-----
> ? From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> ? Behalf Of Brian Michalk
> ? Sent: Monday, November 10, 2008 7:07 AM
> ? To: Velocity Aircraft Owners and Builders list
> ? Subject: Re: REFLECTOR: amount of trim
> ?
> ? Didn't Hiroo Humeno make an autopilot tab out of the sparrow strainer?
> ?
> ? I wonder how that worked out?
> ?
> ? John Dibble wrote:
> ?? When installed per the factory recommendation, the sparrow exerts a
> ?? downward force on the elevator, which must be countered by the trim
> ?? spring.  The faster you fly, the greater the force.  That's why you
> ?? run out of trim at high speeds (IAS).  When reversed, the sparrow
> ?? exerts an upward force, working with the trim spring, significantly
> ?? expanding trim capability.
> ?? Actually, at the risk of complicating this, I believe the sparrow, in
> ?? the reversed position provides more than the necessary force to
> ?? overcome the force of the airstream on the elevator and the trim
> ?? spring is actually now exerting a downward force on the elevator, but
> ?? I don't know how to prove that.
> ??
> ?? John
> ??
> ?? Lou Stedman wrote:
> ??
> ???  Thanks John. I always like to have friends drop by but. I am a bit
> ??? confused, why would I reverse the sparrow? I am not knogleable on
> ??? that subject. Lou Stedman
> ??? Velocity N7044Q
> ??? Olean, NY
> ???
> ???     ----- Original Message -----
> ???     *From:* John Dibble ?mailto:aminetech at bluefrog.com?
> ???     *To:* Velocity Aircraft Owners and Builders list
> ???     ?mailto:reflector at tvbf.org?
> ???     *Sent:* Monday, November 10, 2008 7:28 AM
> ???     *Subject:* Re: REFLECTOR: amount of trim
> ???      Lou,
> ???
> ???     I had the same problem as you.  Right now I'm at the new Dundee
> ???     airport 17NK.  If you're interested I can stop by and you can fly
> ???     with me and see that reversing the sparrow strainer has no effect
> ???     on stability.
> ???
> ???     John
> ???
> ???     Lou Stedman wrote:
> ???
> ????     Thanks Gary. Mine is a little different. When I am solo, I don't
> ????     have enough down trim. I did a new W?B and found out I need
> ????     thirty pounds of ballast in the nose when solo. That helps a lot
> ????     with needed down trim but I can't help but think I need some
> ????     down trim. What model are you flying? Lou Stedman
> ????     Velocity N7044Q
> ????     Olean, NY
> ????
> ????         ----- Original Message -----
> ????         *From:* Gary Stull ?mailto:gstull at tampabay.rr.com?
> ????         *To:* Velocity Aircraft Owners and Builders list
> ????         ?mailto:reflector at tvbf.org?
> ????         *Sent:* Sunday, November 09, 2008 10:17 PM
> ????         *Subject:* Re: REFLECTOR: amount of trim
> ????          I have much more up then down trim. In my case I never need
> ????         any down trim even flying solo, always some up trim required.
> ????
> ????             ----- Original Message -----
> ????             *From:* Lou Stedman ?mailto:stedmanlou at roadrunner.com?
> ????             *To:* Reflector Velocity ?mailto:reflector at tvbf.org?
> ????             *Sent:* Friday, November 07, 2008 5:20 PM
> ????             *Subject:* REFLECTOR: amount of trim
> ????              I have looked through my manual but do not find
> ????             information on how much up and down trim I am suppose to
> ????             have. It does say that the elevator should have 24-26
> ????             degrees of down and 20 degrees of up. But it does not
> ????             mention anything about trim. Can someone shed some light
> ????             on this? I have lots of up trim but almost no down trim.
> ????             Lou Stedman
> ????             Velocity N7044Q
> ????             Olean, NY
> ????
> ????             ------------------------------------------------------------------------
> ????
> ????             _______________________________________________
> ????             To change your email address, visit
> ????             http://www.tvbf.org/mailman/listinfo/reflector
> ????
> ????             Visit the gallery!  www.tvbf.org/gallery
> ????             user:pw = tvbf:jamaicangoose
> ????             Check new archives: www.tvbf.org/pipermail
> ????             Check old archives:
> ????             http://www.tvbf.org/archives/velocity/maillist.html
> ????
> ????         ------------------------------------------------------------------------
> ????
> ????         _______________________________________________
> ????         To change your email address, visit
> ????         http://www.tvbf.org/mailman/listinfo/reflector
> ????
> ????         Visit the gallery!  www.tvbf.org/gallery
> ????         user:pw = tvbf:jamaicangoose
> ????         Check new archives: www.tvbf.org/pipermail
> ????         Check old archives:
> ????         http://www.tvbf.org/archives/velocity/maillist.html
> ????
> ????         ------------------------------------------------------------------------
> ????
> ????         No virus found in this incoming message.
> ????         Checked by AVG - http://www.avg.com
> ????         Version: 8.0.175 / Virus Database: 270.9.0/1778 - Release
> ????         Date: 11/9/2008 2:14 PM
> ????
> ????     ------------------------------------------------------------------------
> ????     _______________________________________________
> ????     To change your email address, visit
> ???? http://www.tvbf.org/mailman/listinfo/reflector
> ????
> ????      ?http://www.tvbf.org/mailman/listinfo/reflector?Visit the gallery!
> ???? www.tvbf.org/gallery
> ????     user:pw = tvbf:jamaicangoose
> ????     Check new archives: www.tvbf.org/pipermail
> ????     Check old archives:
> ???? http://www.tvbf.org/archives/velocity/maillist.html
> ????     ------------------------------------------------------------------------
> ????
> ????     Internal Virus Database is out of date.
> ????     Checked by AVG - http://www.avg.com
> ????     Version: 8.0.175 / Virus Database: 270.8.5/1755 - Release Date:
> ???? 10/29/2008 5:27 PM
> ????
> ????
> ???     ------------------------------------------------------------------------
> ???
> ???     _______________________________________________
> ???     To change your email address, visit
> ???     http://www.tvbf.org/mailman/listinfo/reflector
> ???
> ???     Visit the gallery!  www.tvbf.org/gallery
> ???     user:pw = tvbf:jamaicangoose
> ???     Check new archives: www.tvbf.org/pipermail
> ???     Check old archives:
> ???     http://www.tvbf.org/archives/velocity/maillist.html
> ???
> ???     ------------------------------------------------------------------------
> ???
> ???     No virus found in this incoming message.
> ???     Checked by AVG - http://www.avg.com
> ???     Version: 8.0.175 / Virus Database: 270.9.0/1779 - Release Date:
> ???     11/10/2008 7:53 AM
> ???
> ??? ------------------------------------------------------------------------
> ??? _______________________________________________
> ??? To change your email address, visit
> ??? http://www.tvbf.org/mailman/listinfo/reflector
> ???
> ???  ?http://www.tvbf.org/mailman/listinfo/reflector?Visit the gallery!
> ??? www.tvbf.org/gallery
> ??? user:pw = tvbf:jamaicangoose
> ??? Check new archives: www.tvbf.org/pipermail
> ??? Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
> ??? ------------------------------------------------------------------------
> ???
> ??? Internal Virus Database is out of date.
> ??? Checked by AVG - http://www.avg.com
> ??? Version: 8.0.175 / Virus Database: 270.8.5/1755 - Release Date:
> ??? 10/29/2008 5:27 PM
> ???
> ???
> ?? ------------------------------------------------------------------------
> ??
> ?? _______________________________________________
> ?? To change your email address, visit
> ?? http://www.tvbf.org/mailman/listinfo/reflector
> ??
> ?? Visit the gallery!  www.tvbf.org/gallery
> ?? user:pw = tvbf:jamaicangoose
> ?? Check new archives: www.tvbf.org/pipermail
> ?? Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
> ?
> ? _______________________________________________
> ? To change your email address, visit
> ? http://www.tvbf.org/mailman/listinfo/reflector
> ?
> ? Visit the gallery!  www.tvbf.org/gallery
> ? user:pw = tvbf:jamaicangoose
> ? Check new archives: www.tvbf.org/pipermail
> ? Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
> ?
> ?
> ? _______________________________________________
> ? To change your email address, visit
> ? http://www.tvbf.org/mailman/listinfo/reflector
> ?
> ? Visit the gallery!  www.tvbf.org/gallery
> ? user:pw = tvbf:jamaicangoose
> ? Check new archives: www.tvbf.org/pipermail
> ? Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
> ?
>
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>   ------------------------------------------------------------------------
>
> Internal Virus Database is out of date.
> Checked by AVG - http://www.avg.com
> Version: 8.0.175 / Virus Database: 270.8.5/1755 - Release Date: 10/29/2008 5:27 PM