I've just received photos of the tooling and first article parts for the HP-24 forward fuselage bulkheads. The bulkheads and tooling were made by Precomtec R+D according to sketches I made on scratch paper with a dull #2 pencil.
Bulkhead #1 is the very forward bulkhead where the optional Tost 85- series tow hitch mounts. It is a relatively close copy of the mounting system used in the Discus and Ventus, and is based on salvage parts I bought from JJ Sinclair. I posted a general arrangement drawing of this area in an earlier update.
Bulkhead #2 is the next bulkhead back, just forward of the leading edge of the canopy separation curve. That bulkhead serves as the stiffener and mounting point for the canopy pivot mechanism, and also the forward mount for the rudder pedal slide. It will also serve as a low-pressure partition between the ventilation plenum and the cockpit. The design for that bulkhead evolved slowly over a few months from a simple pan shape into a shape that incorporates the canopy pivot bosses that simplify the pivot weldments.
This update's photos:
In the top row are the #2 bulkhead parts. From right to left, they are: the plug shaped to fit into the fuselage, the mold made from the plug, and finally the finished first article bulkhead. In the bottom row are the corresponding parts for the #1 bulkhead. Note that the parts incorporate a slightly asymetrical joggle near where they meet the fuselage plan of symmetry. That feature is to let the bulkhead clear the bonding joggle that will get molded into production fuselage halves. Also note that the finished first article #1 bulkhead already has the Tost 85-series tow hitch installed.
This photo shows the reverse sides of all the parts except the #1 bulkhead mold. Not that there's much to see on that side of the mold.
page updated 5 February 2004 all text and graphics copyright (c) 2004 HP Aircraft, LLC