A couple of X-15A-2s…

Howdy. Here are a couple of cardmodel X-15A-2 builds. Since eight pilots became astronauts flying the X-15, I thought this would be the category for them.

The black version is a digital repaint of the well-known X-15A-2 card model designed by Ken West, in 1/32nd scale. Ken’s model represents the X-15A-2’s earliest flights, and this repaint depicts Flight 2-50-89, flown 18 November 1966. Pete Knight flew 66671 to Mach 6.3 — 4,250 mph. It was the X-15 program’s first flight past Mach 6 and set an unofficial speed record.

On this particular mission, 66671 carried some test patches of ablative material that were orange in color. The material was on the nose, nose landing gear door, main landing gear, upper left horizontal stabilizer, part of the lower ventral and some panels on the right side tunnel. White stripes (camera targets) were painted on the underside of the fuselage and wings and, yeah, the fuselage stripe was actually a little crooked on the real thing.

I built the model pretty much stock, using 170gsm glossy cardstock. I added a few scratchbuilt details here and there to improve accuracy. I left out the cockpit interior. Once the canopy is on, you can’t see much through the windows anyway. The external tanks were also digitally repainted. The tanks with Ken’s kit represent dummy tanks that never flew. I used aluminum foil to replicate the tanks’ bare-metal sections — highly reflective on the left tank and a dull silver on the right.


The white X-15A-2 is in 1/48th scale, and depicts 66671 as it appeared on Flight 2-53-97. On that flight, on 3 October 1967, Knight broke his own record, hitting Mach 6.7, or 4,520 mph. It was also the X-15A-2’s last flight.

The model is a digital repaint and redesign (to turn it into the stretched X-15A-2) of an X-15 model originally designed by Henry Yuen. His model is 1/87th scale, but I enlarged it to 1/48th.

The white X-15A-2 is fairly popular among modelers, but most modelers (and model manufacturers) get the color and markings wrong for Knight’s speed-record flight. It’s not entirely their fault.

The white coating was an RTV sealant used to cover the MA-25S ablative, which was dark pink. When exposed to liquid oxygen, MA-25S had a nasty habit of exploding if struck. To prevent that, the ablative was covered with a sealant. Technicians sprayed it on, but on the underside of the wings and tailplanes — where the threat of a dropped tool was pretty low — they weren’t worried about full coverage. In-flight photos of the white X-15A-2 show the underside of the wings and tailplanes with a streaky appearance, with pink showing through. The top and rear of the rudder, the top of the housing for the pressurization dome and the ends of the side tunnels were not covered with ablative or sealant.

Now for the markings, which the vaunted Special Hobby kit (and every other kit) gets wrong. By the time of Knight’s speed-record flight, NASA’s photo coverage of X-15 flights was pretty sparse. As a result, some photos of two earlier white X-15A-2 flights (one a captive flight with tanks and another a powered flight without tanks) often get misidentified — even by NASA — as being from the speed-record flight.

On the captive flight, the dummy scramjet had a white nose spike. On the tankless powered flight, the scramjet had a black horizontal stripe. The skids of the main landing gear were covered in an orange ablative material on both flights. The right ventral speed brake had H2O2 COMP. DRAIN and H2O2 JETT on it, in black.

On Knight’s speed-record flight, the dummy scramjet was white but the spike was an orangey color that appeared to be painted freehand. The skids were covered with the white sealant. The right ventral speed brake had only H2O2 JETT on it; the H2O2 COMP. DRAIN notice was omitted.


12 Likes

Same from the other post of yours about the X15s… But also with a welcome to the forums this time…and they are very very impressive builds …:+1:

@Dhanners55, David nice work on these as well. The fuel tanks make the 66671 looks awesome!

Thanks! I’m not sure why it took me so long to get around to doing it but, yeah, it improves the look. Between the tanks, test patches of ablatives, white stripes, etc., that was a colorful X-15A-2 flight.

2 Likes

I have the 1/32 X-15 kit with tanks and dolly and I want to build it someday looking similar to what you have represented. Thanks again for sharing!

These would be cool Dios.


or

was the B36 one ever done ?

2 Likes

Cool. If you have any questions, holler, I can direct you to some good resources. This website is essential — tons of photos: x15index

1 Like

As I recall, after various studies, they decided the B-36 wouldn’t work as a carrier aircraft. One consideration was B-36 production had long ended and there was a concern about getting spare parts to keep the carrier planes flying. Also, the X-15 pilots involved in the development noted that if they were strapped in the cockpit and a serious problem developed with the carrier plane, there was no way to eject. At least that was an option with the B-52.

A friend of mine who was a good cardmodel designer was going to design a pylon, wing section and perhaps inboard nacelles as a display base for the X-15. Sadly, he passed away unexpectedly. It would really look cool because the right side of the B-52 carrier planes’ fuselages had some pretty colorful markings.

3 Likes

David, sorry to hear about your friend. May he rest in peace.

As for B-52 and x-15 combo, there is a 1/72 monogram kit that can be had and you can still find cutting edge markings for other mission choices.

1 Like

Thanks for the link (bookmarked) and offer of help. I sure will keep you in mind when starting mine.

Depending how deep down the X-15 rabbit hole you want to go, I’d also recommend the Dennis Jenkins/Tony Landis book “Hypersonic.” You can find used copies on Amazon. It is considered the authoritative go-to source on the X-15, and is chock-full of photos and diagrams.

1 Like

That would be cool.

1 Like

Yeah, Dennis Jenkins and Tony Landis books are wealth of information and photography. I have several of their books but I will have to take a look if I have one exclusively on X-15.

After looking at your builds, one thing stood out to me was the tail numbers. I wonder why go with 666xx?

I have no clue about the tail numbers and am not enough of an expert in X-planes to know. Normal USAF serial numbering assigns a 5-digit number, with the first two numbers being the year the aircraft was ordered — obviously not the case here as the development contract was awarded in September 1955.

I did a quick look online and found a number of X-planes with 4-digit tail serial numbers beginning with the numeral 6.

As for the 666 thing, I doubt USAF, NACA (later NASA) or the Navy placed any “mark of the beast” significance to the vehicle.

1 Like

Also, here is a detailed history of the program. Not a lot a detail photos, but a ton of good information: https://www.nasa.gov/pdf/470842main_X_15_Frontier_of_Flight.pdf

1 Like

Or maybe it’s alluding toward being a problematic within the machinery. I have read stories where some particular airframes were nightmare to fly and maintain. Just an observation but in reality…who knows except the guys in the program.