December 8, 1992

 SERVICE BULLETIN #27

 

TO:       Kitfox™ Builders with Wing Kits, received between August 92 through November 92

FROM:     SkyStar Aircraft Corporation

It has come to our attention that a small number of Model IV wing ribs may have been manufactured with the capstrips incorrectly aligned with the rib web, at the trailing edge. These ribs could be in kits which were delivered during the months of August through November 1992.

Ribs may be checked by sighting from the trailing edge towards the leading edge to make sure the capstrips are perpendicular to the rib web.

The capstrip alignment of the #27001 rib (NON-FLAPERON HANGER BRACKET RIB) is within tolerance, if the capstrip slant, is .025” or less. Place the rib on a flat surface, with a square perpendicular to the capstrip; measure the distance between the capstrip and square, if it is more than .025” then the rib needs replaced. The capstrip alignment for #27002 ribs (FLAPERON HANGER BRACKET ATTACH RIBS) must be level and perpendicular to the web. It is critical that there be no binding of the flaperon hinge. Ribs, having capstrips which do not meet the tolerance criteria, will be replaced by SkyStar Aircraft, at no charge to our customer. Contact Customer Service for details on how to get your replacement ribs.

If the out of tolerance ribs have already been installed on the wing, then the flaperon hanger bracket area of the capstrip must be heated, pulled lose, and repositioned correctly. Those needing to adjust the capstrip alignment after having assembled the wing should:

Secure the wing to your saw horses so it can not be lifted up. Remove the aluminum trailing edge by heating the bonded areas and drilling out any rivets. Use a heat gun to warm the adhesive in the area to be repaired. With a pair of pliers, rock the capstrip of the rib, back and forth while heating the adhesive, (approximately to 2000 F). The adhesive will break loose, allowing you to pry the capstrip up and expose the staples for removal. With the capstrip heated, it is very pliable, pull it back and scrap the old adhesive off with a putty knife. Re-heat the adhesive if necessary for removal. (Fibers of capstrip material may break away from the capstrip where the bond is broken, this is okay.)

Sand the rib web and mating capstrip side for good adhesion. Use structural adhesive (Scotch Weld Type 2216) to glue the capstrip back on to the web material.

You can make a gluing jig, from scrap plywood, that will slip onto the trailing edge of the rib, to get the web and capstrip square. Or, you can bolt the halves of the flaperon hanger brackets together and clamp a hanger bracket on to repaired rib. Mark these brackets and attach them to the same hanger rib upon installation of the brackets.

If you have any questions regarding this Bulletin, please feel free to call the SkyStar Technical Department at: Ph. (208) 466-1711 or Fax (208) 466—7194.