North American X-15A-2

Kit:	Monogram, 1/72; model completed in 2022-03-01
Aircraft:	56-6671, NASA & USAF, Edwards AFB, circa 1965

The X-15 was an experimental rocket-powered aircraft designed to study hypersonic speeds. Three aircraft were built, the first one of which flew in 1959. The research program continued until 1968, and a total of 199 flights were made. The X-15 still holds the official speed record for manned, powered aircraft (approx. Mach 6.7).

The model represents the second X-15 built, after its conversion to use a single rocket engine and longer fuselage. This aircraft is currently preserved at the USAF Museum in Dayton, OH.

56-6671 in flight (NASA photo)

Construction Notes

The Monogram kit is from the 1980s and in many ways is rather simple and crude. It is accurate, though, when it comes to shapes and measurements, but requires work when it comes to details. Because there is lots of good reference material about the X-15, I decided to leave the canopy open and detail the cockpit appropriately. The ejection seat and the instrument panel parts from the kit were fine, and I took time to carefully paint them; I did, however, replace the control column and added supports to hold the canopy open.

The canopy itself had to be modified to represent the particular configuration of the aircraft I wanted to reproduce. It is important to understand that these were research vehicles and probably looked different from one flight to the next. In this case, the canopy had two oval windows, whereas the kit comes with the left hand side window covered with panels that could be opened during landing. I cut a hole in the part, bigger than needed, and also enlarged the existing hole. I then cut panels from 0.15 mm acetate and glued them in place; some acrylic putty and Mr.Surfacer 1000 was used to blend them in. I then cut oval masks, the right size, from masking tape and painted the whole part charcoal gray. The result is very good and even on the right hand side much better than could be achieved using the kit window.

The nose landing gear strut is incorrect, and the door is unusable, so those had to be corrected/replaced. See photographs of the real thing for details (there is one below).

The X-15 could not take off on its own power, but rather was dropped from a modified B-52 "mothership". The main landing gear were "skids" rather than wheels. I decided to show those in their retracted position, and instead placed the model on a dolly that was used to move the aircraft on the ground. The kit's dolly is decent but requires some cleanup and additional detailing, as well as the hydraulic struts to be extended more; the "spares box" and Albion Alloys aluminum tubing came to the rescue. I painted the dolly with Mr.Color #58 (orange), including the wheels, and then oversprayed the wheels lightly with Mr.Color #114 (red) to account for the different color shown on many photographs.

The aircraft after initial painting with three different colors

Lower contrast after the application of a black filter

Canopy after modifications

Tail with newly painted orange stripes

The X-15 aircraft were not painted, and they were not completely black like the kit instructions (and many other sources) suggest. From careful study of photographs I concluded that I could use three different colors (black and two dark grays). I carefully masked the model to show different panels; this was the most time-consuming part of the project. I airbrushed the model with Tamiya acrylics, using XF-1 (black), XF-69 (very dark charcoal gray), and XF-63 (dark gray). After painting, the contrasts between the different colors were still too great, so I applied more black, diluted maybe 1 part paint, 8 parts of thinner, as a "filter", and this brought the contrast down. I feel the model now matches the photographs nicely. For the various natural metal parts I used Alclad II lacquers. Note that when painting the model, one should not mistake frost and condensation in the mid-fuselage for actual aircraft color (it is visible in many photographs).

The kit decals were very thick but generally went on just fine. Some were incorrect and had to be replaced. Most notably, the orange stripes in the vertical tail had white lettering, so I painted the stripes using Mr.Color #58 and made my own decal for the text; I printed the decal using a laser printer on transparent decal film which I then coated with Liquid Decal Film. Note that, over time, the markings on X-15s were changed a lot, so you will see subtle (and not so subtle) differences, for example in the exact placement and orientation of markings and stenciling. Luckily, there are a lot photos of X-15s available.

I sprayed the model with Alclad II Gloss Klear Kote both before and after decals, and finished with Alcad II Klear Kote Semi Matte. The Alclad clear coats are fantastic, they airbrush well without thinning, dry in an hour, and being lacquer-based are insensitive to water when applying decals.

The first X-15 preserved at the National Air and Space Museum in 1993 (SMA photo)

56-6671 at the USAF Museum in 1995 (SMA photo)

Replica of the third X-15 at the NASA Dryden Flight Research Center at the Edwards AFB in the Mojave desert, photographed in December 1995 (SMA photo)

Boeing NB-52B mothership (52-0008, "Balls Eight") at the NASA Dryden Flight Research Center in December 1995 (SMA photo)

References Used

These are some of the reference sources I used. [2] is an indispensable reference for anyone building an X-15, [5] is a companion book with more photographs. [3] has useful color profiles and also discusses the different kits available.

Aerophile vol 1 no 2 Mar/Apr 1977
Hypersonic - The Story of the North American X-15 (Jenkins & Landis); Specialty Press 2002
Scale Aircraft Modelling May 2007
Scale Aircraft Modelling November 2016
X-15 Photo Scrapbook (Landis & Jenkins); Specialty Press 2003
photos from the NASA Dryden photo archive
my own photos from various museums

The model received 3rd place in the category "Aircraft: Jets 1/72nd scale and smaller" at Downeastcon 2022 (Southern Maine Scale Modelers; Sanford, ME) on 2022-04-10.