December 14, 1992

SERVICE LETTER #24

SUBJECT:   PROPELLER INSTALLATION, TORQUING PROCEDURES, and MAINTENANCE

TO:  ALL Kitfox™ OWNERS

FROM:   SKYSTAR AIRCRAFT CORPORATION

Several issues have recently surfaced regarding the installation and maintenance of propellers installed on Kitfox™ aircraft. Proper propeller installation is absolutely essential to safe flight. Regular maintenance checks should be performed every 25 hours , at annual inspections, and 100 hour inspections; in addition to regular pre-flight inspections. This letter will review the significant facts regarding the care and installation procedures, torquing sequence, maintenance, and the use of SkyStar spinners with propellers other than GSC.

GSC PROPELLER INSTALLATION

The Kitfox™ construction manual directs the builder to install three drive lugs into the prop flange to help secure the bulkhead; current information from GSC indicates that “six” drive lugs are now called for.

NOTE:

Up until this Letter, all Kitfox™ spinner bulkheads have been drilled for three drive lugs and six bolts. The application to six drive lugs will require each builder to drill the three extra holes in the spinner bulkhead (these holes already exist in the propeller flange and bulkhead) . With three studs already in place, attach the spinner bulkhead on the flange and mark the other three hole from the back. These lug holes should be drilled with a Letter size “N” drill. The use of Loctite is recommended on these studs.

These drive lugs are available through SkyStar for a cost of $1.50 each, Part #91237.

GSC TORQUE SPECIFICATIONS

It is absolutely essential, to torque the GSC propeller mounting bolts to the exact values dictated by instructions from GSC, for safe flying. If the GSC Ground Adjustable propeller is not torqued properly, it is possible for the blades to become loose, with a random pitch change occurring that will cause considerable vibration.

SKYSTAR SPINNERS

The current spinner that is supplied by SkyStar Aircraft is designed specifically for use with the GSC propeller hub arrangement and is not  applicable with any other propeller installation.

We have received several reports of SkyStar spinners cracking, and in some cases actually departing the airplane when installed on a non-GSC prop. For those who are using the IVO Prop, the small “skull cap” provided by IVO works well and should be used in place of the SkyStar spinner.

Please feel free to contact SkyStar’s Customer Service Department for parts orders, or the Technical Department for questions concerning this Service letter at: Ph (208) 466-1711 or Fax (208)466-7194.