Hi Ed
I am currently doing just as you propose. First, regarding the leading
edge, I had someone come into my hangar as I was working on the first wing,
and mentioned that he had spoken to Harry Riblet about the Kitfox wing. I
can't recall who it was, unfortunately. Mr. Riblet said that the biggest
problem with the Kitfox design was that the most critical portion of the
airfoil was the initial 10% of chord on the upper surface. That is the
first five inches on our wing. That is where the fabric on the typical
Kitfox wing dips down behind the forward spar between the ribs and false
ribs. In talking to others, I suppose the major performance benefit, if
there is in fact such a thing, would be near stall where flow separation
starts - maybe reducing stall speed. Cruise, don't know, but laminar flow
should be improved.
I have done one wing and there are some tricks. Some I solved and others I
guessed at with proof after flight. Regarding oil canning, a possibility, I
suppose, but there are lots of airplanes out there with aluminum leading
edge - Rans for example.
Lowell
----- Original Message -----
From: "Ed Gray" <egraylaw@swbell.net>
To: <kitfox-list@matronics.com>
Sent: Wednesday, October 08, 2008 12:25 PM
Subject: Leading edge
> Needing advice or input about leading edge.
>
>
> Now building KF II and about to cover wings. I have installed the new
> plastic leading edge cuff and intend to cover the upper leading wing
> surface
> with aluminum over the upper false ribs. The alum. Is 12 inches wide and
> will butt against the leading edge cuff, epoxied and riveted to the ribs
> and
> spar, and covered with ceconite. My concern is the potential of
> oil-canning
> or ripples due to wing flexing. The purpose is to smooth the leading
> edge.
> The weight penalty is six pounds (maybe less since less finish will be
> needed). I plan on segmenting the aluminum material at alternate ribs to
> avoid oil-canning. Either cut the material completely or slit it from 2
> inches behind leading edge through the trailing edge with a saw kerf.
>
>
> So, all you engineers (pro or otherwise), please think this over and post
> your input or advice. Also, my fuel system plan is each six gallon wing
> tank routed to the alum. 1.1 gallon header tank mounted behind the right
> seat, which feeds into a facet pump under right seat then to the supplied
> cutoff valve below the throttle cable, then to the gascolater on the lower
> right front side of firewall, then up to the impulse pump on the firewall
> and out to the bing carbs on the 582. Vapor return line from the alum
> header back to the right wing tank. The left tank will have a fuel valve
> on
> the headrack, so I can isolate the two tanks and only fuel the right side
> for short flights. Plan to use the Facet on takeoff and steep climb, per
> Lynn Mattesen. Anyone see problems with my plan? Thanks for advice. Do
> not archive.
>
>
> Ed Gray, Dallas, KFII No. 705, 582 grayhead, GSC 3 blade
>
>
> PS I have a backpack emergency chute to wear while I test the plane. I
> have
> jumped before, but does anybody know someone who has bailed out of a
> Kitfox,
> ie. Any problem getting the door open or clearing the lift strut?
> egraylaw@swbell.net
>
>
