The Northrop HL-10 was an experimental wingless “lifting body” aircraft that flew in the late ’60s and early ’70s. As the box art above indicates, it’s familiar to many people of a certain age from the opening sequence of the television series The Six Million Dollar Man. It was one of a series of lifting body designs that were tested after being dropped from under the wing of a modified B-52 bomber. (In the Six Million Dollar Man sequence, the character Steve Austin is dropped in the HL-10, but contrives to crash the M2-F2. The film used was of a real crash, on 10 May 1967, which very nearly killed its pilot, Bruce Peterson.)
Here’s the HL-10 and its B-52 mothership, showing the underwing attachment from which the lifting body was released:
And the other side of the aircraft, with the four principal test pilots having a bit of a lark:
Fantastic Plastic are aiming to produce a matched set of 1/48 scale resin kits of several lifting bodies: Northrop’s HL-10 and M2-F3 are available, with the Martin-Marietta X-24A and X-24B still to come.
The HL-10 kit is simple enough, in theory—just 37 pieces, including transparent parts for the cockpit and nose canopies, and a little bit of photoetch, styrene rod and wire for some finer detail, including that long nose probe. Resin kits always require a bit more work, sawing parts off pour stubs and straightening distorted parts, but this one rapidly turned into an assault course. The assembly instructions are not clear, consisting of a few blurry photographs, so it takes a bit of fiddling around to work out the correct fit of the cockpit parts—I still have no idea if the control column is in the intended location. And the decal sheet was very poor, with quite a lot of damage that appeared to have occurred during the printing stage, rather than from any later rough handling. (I contacted Fantastic Plastic about this, wondering if I could obtain a replacement, but received no reply.)
So frustrating was this build, in fact, that I find I have an unusually poor photographic record of it—on more than one occasion the kit was only a night’s sleep away from ending up in the bin.
The cockpit is basic, much of it moulded into the lower half of the fuselage. I added some detail using harness straps from an old Airwaves photo-etch set I found in the spares drawer, and some instrument dials from Airscale’s Early Allied Jets decal sheet. The ejector seat of the HL-10 was a modified version of the one used in the F-106 Delta Dart, so I was able to use photographs of the F-106 seat for reference. The rest of the cockpit doesn’t seem to be very well documented. I did the best I could with one photograph and one video. (Since then I’ve discovered a couple more poorly reproduced photographs in NASA Technical Memorandum X-2956.)
Here’s the result, before I closed the upper fuselage half over the lower:
There then followed a huge amount of trimming, filling and sanding, to remove the seam between upper and lower fuselage halves, and between the fuselage and the lateral fins.
The rear of the fuselage, in particular, needed a lot of work to fix the bad fit between upper and lower parts—I used styrene sheet and a lot of epoxy to smooth out the centre section, and some cyano-acrylate to fill chips in the resin along the rear edge that faired into the elevons.
I also drilled the resin to create mounting holes for some miscellaneous tubing that protruded from the rear of the aircraft, and the long probe that was mounted under the nose. The various control surfaces needed a lot of dry fitting and adjustment to get a halfway acceptable fit. I replaced the kit’s paired rudders (which were too short) with styrene sheet, and snipped a small amount off some of the fin flaps (which were too long).
Then I started airbrushing with Alclad II, which was something of an experiment for me—I was going to try to preserve the bright metal finish of Alclad’s polished aluminium lacquer by avoiding spraying any varnish sealant on top of it. This proved to be a mistake, in my hands at least, for reasons I’ll come back to.
Once I got my metallic coat on, it showed up a couple of irregularities that I’d missed during preparation and priming. I would have accepted these, because they were relatively minor, when I also belatedly realized that the kit had omitted the narrow fairings along the upper edges of the lateral fins, which extend rearwards above the control surfaces. These are obvious in photographs (like this one) of the HL-10 taken where it’s on display at the Armstrong Flight Research Center in California, and I was going to have a very ugly result if I left the fin flaps uncovered at their upper edges.
So I used a little styrene rod to add the fairings, then performed another round of filling and sanding before applying primer again. (Fortunately, in a way, the kit has very little surface detail, so multiple layers of paint weren’t a problem.)
Here’s the final result, just waiting to be polished up with Alclad’s micromesh cloths:
And here’s the nice result you get when you apply the metallic paint after all the filling and sanding and polishing:
(The eagle-eyed will notice that these images were taken after the first round of painting, before I added the fairings which are visible in the photos of the primed model.)
Meanwhile, the control surfaces and undercarriage covers were receiving the same treatment, and I assembled and brush-painted the wheels.
Next, I needed to add that characteristic white “swoosh” to the upper surface and sides of the model. Fantastic Plastic provide a couple of templates on their instruction sheet. They look like this:
The idea is that you cut them out, transfer the patterns to masking tape, and then mask the model. Sadly, I couldn’t get them to fit as printed—aligning the mask on the upper fuselage led to the mask being misaligned on the fin, and vice versa. I eventually used the template to cut masks for fin and upper fuselage separately:
I positioned these, then used a strip of masking tape to produce the lower border of the swoosh. Here’s what it looked like all masked up (with little blobs of liquid mask solution at the joins to stop paint leaks):
I then airbrushed on the “swoosh” using Alclad’s Flat White.
Then I set about adding the control surfaces and undercarriage parts, using Microscale’s Krystal Klear as a mild adhesive that I knew wouldn’t damage the metallic finish.
With all the weight of resin at the rear, and no space for a counterweight in the nose, I resorted to adding a clear acrylic rod as an unobtrusive tail support.
Next was the decalling. I scanned Fantastic Plastic’s damaged decal sheet, and set about repairing it in my antique version of Paintshop Pro. For some of the markings I was able to copy an intact decal from one side of the aircraft to repair a damaged decal from the other side; for some I just tidied up ragged edges; and some I redrew from scratch. Then I printed the final version on Experts-Choice decal paper, both clear and white versions, and sealed with Microscale’s Liquid Decal Film. I also cut a few narrow strips off the edge of the white decal sheet, so that I could reproduce the white borders around the canopy edges that I could see in some photographs. This worked well for the relatively straight edges of the cockpit canopy:
I had less success around the tight curves of the nose canopies, where the decal strip ended up looking oversized and slightly wrinkled. (In retrospect, I’d probably have been better off using a sheet of white stripes from Xtradecal, rather than trying to create my own.)
The other decals went on fine—my substitutes worked pretty well, in the main, though the red lettering looked somewhat subdued compared to the original. For the fine black line that bounds the white swoosh paintwork, I divided the decal in three and mounted the parts separately, trimming to length to fit my own mask-work.
But at this point the holes in my plan to leave that lovely Alclad metallic surface unsealed became painfully evident. Firstly, the decal film produced a very slight change in the reflectivity of the underlying metallic finish, which catches the eye from some angles. Secondly (and much more annoyingly) my handling of the model while positioning the decals wore away some of the delicate Alclad surface—at best taking the shine off, at worst showing a hint of the underlying black primer. It’s particularly annoying because there were ways to grip the model that would have avoided handling the metallic surface. Ah well. In the immortal words of Gerry Rafferty, “if you get it wrong you’ll get it right next time.”
Finally, I pieced together a version of the long nose probe from the styrene rod, wire and photoetch provided by Fantastic Plastic, and mounted the open canopy.
Below is the final result. The kit’s undercarriage legs have turned out to be too long—the aircraft looks a little as if it’s up on stilts. Normally, I’d remove, shorten and replace, but I can’t see a way of doing that without ending up damaging the metallic surfaces some more.