Special Hobby X-15A-2 “White Ablative Coating” (SH32081) 1:32

[Mike]

X-15A-2 “White Ablative Coating” (SH32081)

1:32 Special Hobby

 

 

After Chuck Yaeger broke the sound barrier (officially) in the X-1, the series of experimental high-speed aircraft continued in the shape of the North American built X-15, which began in 1954, with the programme continuing until 1968, and extending to just short of 200 flights of this manned missile throughout many flight-envelopes, collecting data and experience that would be used to great effect in the following Mercury and Apollo programmes, which shared some crew, as well as furthering the understanding of atmospheric flight at high speed.  It was carried aloft by a modified B-52 Stratofortress known as a 'mothership', then released, and when applicable it would ignite its rocket engine that would burn for an amazingly short time of around 80 seconds, propelling the aircraft up to a toe-curling 4,500mph.  Initially it utilised two Reaction Motors rocket motors, but these were replaced by their immensely more powerful single XLR99 engine, which was powered by anhydrous ammonia and liquid oxygen, and perming solution (hydrogen peroxide – probably quite a bit more concentrated than that used to turn your hair curly) to drive the pump that fed the engine, which could be throttled up and down thanks to advances in technology after WWII.

 

There were three aircraft built, and one was lost in a mid-air breakup that sadly killed the pilot.  X-15A-2 also crash-landed, ending the day upside down and leaking fluids all over the lake bed they were using as a runway, but it was recovered and rebuilt.  It was lengthened by a couple of feet and given massive additional fuel tanks to extend the run-time of the rocket engine.  It was also coated in a white ablative paint that helped to ameliorate the excess heat that was generated by such fast transit through even the most nebulous of atmospheres. In the end A-2 flew a total of 55 missions in its different guises before the programme came to an end in 1968, when the delay of the 200th flight by continuing bad weather led to its permanent cancellation in favour of the Mercury programme.

 

 

The Kit

This is a reboxing of the improved tooling of the original 2007 X-15 kit from Special Hobby that was later upgraded to be able to depict the later launches that used the big fuel tanks under the belly.  This boxing also includes a stand for the finished model, allowing a wheel/skids up pose that was the aircraft’s natural environment, way, way up in the sky beyond the majority of the atmosphere.  It arrives in a reasonably sized top-opening box, and inside are seven sprues in grey styrene, a staggering 165 resin parts (many tiny ones), a clear canopy part, a sheet of Photo-Etch (PE), a small slip of clear acetate with black printing for the instruments, a length of wire and a glossy instruction booklet with spot colour throughout.  I forgot to photograph the wire, sorry!

 

This isn’t a simple scale-up of their flawed 1:48 kit, and most of the issues present in the smaller kit aren’t present in this larger model.  According to my Secret Advisor, there are one or two items such as the hemispherical nose tip being a little small, and the low-slung supplementary fuel tanks may be a few millimetres short, but that would only be visible from a side-on view if you knew where to look.  Overall it seems to be a good replica of this amazingly fast space-plane, depending on where your idea of space begins of course!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Construction begins with the combined cockpit and nose gear bay, starting with the rudder pedal box, which is faced with a laminated PE and acetate instrument panel.  This is placed on the cockpit floor, and has side consoles, and rear bulkhead with stepped rear plus shaped top inserts, then at the front a bulkhead with the three-part nose bay is attached to the front.  The additional joysticks are applied to the side consoles, followed by the building of the ejection seat, which has a large number of plastic and resin parts plus PE belts for the pilot, the completed assembly sliding onto the launch rail that is glued to the rear bulkhead of the cockpit.  The main instrument panel is made from three sections and each has PE detail for the instruments, while the centre also has a piece of printed acetate behind it for the dials.  More PE instruments fit to the front of the side consoles, and have small PE levers fixed in place to depict the controls.

 

The fuselage is quite long at this scale, so the top and bottom halves are each made up from two panels, tapering to the nose at the front, and very blunt toward the exhaust of the XLR99 engine.  Small parts are added around the cockpit and at the rear of its fairing, then the cockpit is glued to the upper fuselage so that the two halves can be joined together and have a small hemispherical Q-ball nose added.  The wings aren’t particularly large, and are portrayed with two parts each that fit into the fuselage on lengthy tabs, as are the elevators with the addition of a swash-plate at the pivot point.  A scrap diagram shows the correct anhedral of the elevators, plus the blocky tail fins, which are next.  Due to the weird aerodynamic requirements of such a fast aircraft, the fins are blunt and don’t work all that well at slow speeds.  They are made up from various parts, and there is an optional set of parts to depict the dive-brakes at the rear in the open position.  The fuselage is detailed underneath next, and has a suite of probes and hollow-tipped exit pipes in the front section, then has the simple twin-wheel nose gear strut built and fitted with the bay door on a stand-off bracket behind the leg, which has a small flap in the lower section, presumably to help deal with dust kicked up on landing.  Under the rear a small vertical “tail” assembly hides away more dive brakes, which can also be posed open by adding jacks to the mechanism to project the aft edge of the two surfaces away from the centreline.  A pair of strakes fit on either side of this fairing, after which the exhaust for the rocket motor is put together around the outer lip, and having various sensors and vents arranged around it, plus a deep tapering trunk that gives the depth to the exhaust. When finished it slots into the rear of the fuselage.

 

The canopy has small elliptical windows in the front, which are moulded into the clear canopy, and has a stiffener brace attached to the inside at the rear, that can be posed open or closed.  An optional resin piece can be installed over the port window depending on the mission you are planning on depicting, but no information is given as to when this was used until you look at the two decal options, both of which have the panel.

 

The two additional fuel tanks are made up from two large halves split vertically, with small inserts added to holes in the top sides.  They seem simple, but on the upper surface they have a mass of hoses and equipment, plus the big attachment points where all those pipes enter the underside of the fuselage.  PE brackets, wire, resin and plastic parts go into the detailing of the tanks, and you are provided with plenty of overhead and scrap diagrams to assist you in getting it right.  Take your time and pay careful attention while performing this part of the build and you shouldn’t go far wrong.

 

Ground handling of the airframe employed the nose wheel and a two-wheeled dolly arrangement that attaches to the rear of the fuselage astride the rear dive brake fairing.  This is a complex assembly, and is mostly resin with a little wire and PE parts added for good measure, then painted hi-viz yellow and fitted with two wooden blocks that were inserted under the stanchions when parked.  There is a whole page of diagrams showing the correct arrangement of parts, and how the wooden blocks were utilised, so again take your time to get it all together in the correct manner.  On the last page the large tanks are fitted, then joined by the rear gear trolley or an optional dummy ramjet that was carried by decal option A after loading onto the mothership to test the effects of its aerodynamics on the airframe.  It wasn’t good, and caused a substantial amount of damage thanks to the speed the air moved around it, causing the tail to lift and the skin around it to burn and melt.  The pilot luckily managed to nurse his aircraft back to base unhurt, but the damage was never repaired due to the end of the programme.

 

 

Markings

The repaired A-2 flew with the white ablative coating applied, so the overall look of the aircraft changed markedly.  Many flights were made, and small differences appeared and disappeared as the aircraft evolved.  The decal sheet covers one flight of this airframe before and after it was mated with the B-52, with a separate page covering the complex scheme that was applied to the fuel tanks.  From the box you can build one of the following:

 

• X-15A-2 56-6671, Pilot William ‘Pete’ Knight, flight 2-53-97, 3^rd October 1967.  Already lifted from the trailer and hung on the B-52 mothership, ready for the first stage of hypersonic flight.  When the X-15 had been fitted to the B-52, the Ramjet dummy was then fitted to the ventral fin.
• X-15A-2, 56-6671, Pilot William ‘Pete’ Knight, flight 2-53-97, 3^rd October 1967.  The aircraft configured as it appeared before its very last record-breaking flight.  The machine is positioned on the servicing and transportation trailer just before being towed to the B-52 mothership.

 

 

 

Decals are well-printed and consist mainly of stencils and warnings in red, black and some are on a silver background, so the majority of the spot colour around the airframe will need to be painted, with the stripes posing the most technical aspect of that task.

 

 

Conclusion

If you haven’t got one already and are interested in early hypersonic research, this will be a highly interesting topic for you, and it builds up into quite a long model at slight over 50cm for the fuselage, plus a few cm for the pipes at the rear.  There is a lot of documentation out there for those wishing to portray their X-15 as realistically as possible, and the addition of a stand should come in handy for those with limited shelf-space.

 

Highly recommended.

 

 

Review sample courtesy of

[Willi3d]

Great review.  The decal options are only for Flight 188, the record setting Mach 6.72 flight, so the resin “eyelid” for the port cockpit window is correct for either scheme.  The issue was that as the white ablative coating burned off, residue would be deposited on the cockpit windows, which would inhibit the pilot’s ability to see and safely land the aircraft.  The premise was that the eyelid would be closed for the beginning and high speed portion of the flight, and then when beginning the approach, the eyelid would be opened, allowing the pilot a clear view through an undamaged window.  HTH.

[JohnT]

The book I am reading about the history of the shuttle program tells quite a bit about the X-15 flights. I read with interest that some X-15 pilots got high enough to qualify as astronauts and that our late great Eric Brown was under favourable consideration as a pilot for it but it never happened unfortunately. To think he could have been the first Briton in space!

[dhanners]

I know this thread is a couple of years old, but I just stumbled across this review and thought I could add some info for folks modeling the X-15A-2 in the future. While I have no experience with the kit (I’m a card modeler…) I have researched X-15 markings and believe I can offer some clarification/insight into the white X-15A-2 and how it looked in August, September and October 1967.

 

The vehicle depicted on the box art and on the instruction sheet is a mish-mash of two different missions; if you use the instructions as a guide, you won’t be modeling Pete Knight’s speed-record flight. The vehicle depicted in the box art and instructions has elements from a scheduled captive flight and the speed-record flight. It’s a common error among modelers because photos from that era are often misidentified online and in books. By the summer of ‘67, NASA was skimping on photo coverage of X-15 missions. In fact, when Knight made his speed-record flight, he hired his own photographer to document it.

 

The white ‘A-2 made only two free flights. The first time it was airborne was a scheduled captive flight, 2-C-93, on 7 August 1967. It was a test to cold-soak the vehicle with the external tanks, so on this flight, 66671 carried the tanks and a dummy scramjet. The scramjet had a white nose spike. The skid portions of the rear landing gear were covered in an orange ablative. The right ventral speed brake had H2O2 COMP. DRAIN and H2O2 JETT (as depicted on the box art discussed above) on it, in black. In some publications and online, photos from this flight are sometimes misidentified as being from the speed-record flight. Special Hobby’s error is not unique.

 

The next two missions — 2-A-94 on 11 August 1967 and 2-A-95 five days later — were aborted before launch. Both flights lacked external tanks and carried a dummy scramjet.

 

The first free flight of 66671 in full ablative/sealant was mission 2-52-96 on 21 August 1967. The dummy scramjet was all white (including the spike) and the body had a horizontal black stripe. There were no external tanks. The skids had the orange ablative.

 

Knight’s speed-record flight was mission 2-53-97 on 3 October 1967. This time, the dummy scramjet was white but the spike was an orangey color that appeared to be painted freehand. The skids were now all white. The right ventral speed brake had only H2O2 JETT on it; the H2O2 COMP. DRAIN notice was omitted.

 

A note on the color: The white on 66671 was a sealant used to cover the MA-25S ablative, which was a dark pink. If exposed to liquid oxygen, MA-25S has a nasty habit of blowing up if struck with something, such as a dropped tool. To prevent explosion, the ablative was covered with a sealant.

 

The threat of a dropped tool striking the undersides of the wings and tailplanes was minimal, though, so technicians didn’t bother covering them as heavily as the upper surfaces. The coverage of the sealant on the undersides of the wings and tailplanes was quite streaky; in-flight photos of the underside clearly show the streaking. The pink ablative shows through. While I’ve not seen every X-15A-2 model ever built, I’ve not seen anyone model this correctly.

 

The ablative and sealant was not applied to the top and rear of the rudder, nor was it applied to the upper portion of the helium tank structure behind the tail. Similarly, the exposed (lower) surface of the third skid was left uncovered.

 

I hope all this helps….

Edited February 26, 2023 by dhanners

[Shalako]

Beautiful kit. Pity that it is not within my scale-range but I'll just have to wait a few more years, until my presbyopia gets much worse!

[Mr_Sworld]

You could do a good 'What If?' with this kit, as it was flown by Captain Larry Trainor from DC Comics Doom Patrol when he became Negative Man.