HP-18 Center Stick Project

I am now taking firm orders for HP-18 retrofit center stick kits. I'd like to make it clear that there are a couple of caveats:

• The prototype installation has been flight tested for only 4.7 hours. However, it performed just fine during that program. The brevity of the flight test program was largely due to unrelated aircraft and schedule problems. The prototype installation was tested to input forces of 100 lbs in pitch and 70 lbs in roll.

• The pitch trim system is still not finalized, and may not be by the time retrofit kits are shipped. At best, I'll include parts for a trim system that has been ground-tested but not flight tested. At worst, I'll supply diagrams of the system installed with the prototype.

• The builder must send me their 18-441-1 for modification to center-stick configuration.

• The push-pull cover for the right side of the cockpit is still not finalized, and may not be by the time retrofit kits are shipped. The kit will include a metal cover that adequately performs the necessary function. However, the metal cover takes up much more cockpit volume than necessary. Hopefully, some enterprising builder will develop a composite cover that takes up less space.

• The kit includes all essential weldments, bearings, hardware, and materials, and a set of installation procedures. The builder must supply fiberglass resin (we suggest polyester), and some other minor hardware and materials.

• The kit builder must make the necessary adaptations to the seat pan and instrument pedestal of their individual ship. There is so much variation in these areas that I cannot account for all them in the installation procedures.

The lead time stands at 6 weeks.

The stick-mounted cable-drive wheel brake handle is available for an additional $25.

To order, send a note with your name, aircraft serial number, and a check for $150 to:

HP Aircraft, LLC
PO Box 1623
Murphys, CA 95247