X-planes, Part One

I did manage to get some modeling in during the Christmas holiday. Not a lot, and nothing very serious. I certainly planned to do a lot more - I have a bunch of half-built WWI biplanes that need attention - but the point of a hobby is to have fun, right? If I assign deadlines and make schedules, then I've turned a hobby into a simulation of work, and who wants THAT? And besides, sometimes there are simply unexplained lulls.

But I did manage to finish three old X-15 kits, and the Anigrand X-20 I bought at the IPMS convention. I chose them in part because most of the work I could do on the side while watching Christmas movies with my wife, and in part because I was starting to worry that the heat in the garage was going to seriously damage the X-15 kits and their decals, and wanted to get them done and out of harm's way.

The hypothetical X-15A5, converted from a Monogram 1/72nd scale X-15A2. The X-15A5 was never built, but drawings and photographs of wind tunnel models exist, with enough variation in them to permit the modeler a certain latitude for interpretation. The main modifications: 1) Sawing the fuselage in half and inserting a scale six-foot plug. 2) Cutting off the wings and installing new sharply-swept delta wings cut from 0.060 sheet plastic, sharped at the leading edges with sandpaper and with elevons scribed into the trailing edges. 3) Adding an expansion nozzle to the engine exhaust, in this case the nose sawed off a 1/32nd scale F-16 Falcon drop tank. 4) Grafting the two side-by-side propellant tanks end-to-end to make a single long external tank. 5) Cutting apart the serial number decal and reassembling it out of order. 6) Adding wingtip plates cut from 0.040 plastic with a little stretched sprue as a stiffener. 7) Sanding off all the raised panel lines and the raised fairing for the camera port on the underside. 8) Replacing the malformed ball nose with a lump of sprue.

A better view of the sharp sweep angle of the delta wings.

Monogram's 1/72nd scale X-15A2, as configured for Pete Knight's record-breaking flight where he reached Mach 6.71 (and where the X-15 itself was seriously damaged by shock wave impingement and aerodynamic heating). The white color is a protective finish that was applied over the pinkish MA-25 ablative insulation coating. Though this was the fastest X-15 configuration, I find it the least photogenic. In photographs of the real X-15A2, the white coating shows very prominent discolored panel lines, but I chose not to recreate them. The model is lucky that I actually scribed in the missing rudder hinge line!

Even more bland! On this side, there isn't even a window, just the "eyelid" covering the port-side window. The ablator outgassed at high speed, as it was supposed to, but the residue fogged the windows. So the engineers fitted the aircraft with a mechanical eyelid that would protect one window during high-speed flight, and then open up to expose the unfogged window so the pilot could actually see the dry lake during his approach. There is actually a lot of interesting "window lore" in the X-15 program. Such as the fact that the oval window was adopted because the early rectangular window developed stress cracks at the corners and tended to shatter in flight. Such as the fact that the pilots couldn't see any part of the aircraft itself through the windows in any direction.

The silver panels on the nose are silver-painted bits of clear decal film, intended to represent the protective blast panels surrounding the paired nose thrusters (in the X-15 program, this was the "Ballistic Control System", equivalent to Apollo's "Reaction Control System" and the modern "Attitude Control System"). I am currently debating whether I want to indicate the thruster ports by drilling them out, by punching tiny disks out of black decal film, or dotting them with a black marker.

If the Monogram kit has one major weakness, it is this: the aft landing skids are molded in the folded position. If you want to display the X-15 in a "just-landed" state, you'll have to cut apart the folded skids or make new ones, or plop it on the ground-handling dolly with a tow vehicle. But I like the in-flight appearance and used the stands (how gauche!).