Northrop N-9MA by Sword

1/48 scale
Kit No. WE 48001
Retail: $90.00 – $140.00 aftermarket (out of production)
Decals: One version – U.S. (experimental aircraft)
Comments: Detailed resin cockpit, engraved panel lines, vacuform canopy, two-blade propellers

History

First flown two days after Christmas, 1942, the Northrop N-9M was an interim flying wing test bed and a follow-on research aircraft to its predecessor, the smaller N-1M. Representing an incremental increase in size and power, it would ultimately aid in engineering, design and development advances that would culminate in the Northrop XB-35 and the jet-powered Northrop YB-49 flying wing bombers.

Its construction was much like that of the N-1M (which featured a wingspan of 38.72 feet, compared to the N-9M’s 60 feet) and was primarily of wood, specifically mahogany and spruce. Metal components used only where absolutely required. In all, four versions of the N-9M were built, but each differed in their control surfaces, radio, and electrical equipment.

The N-9M was literally a stepping stone between the N-1M and the much larger XB-35, yet another flying laboratory to continue the exploration and refinement of the flight characteristics of the flying wing. Scaled to be one-third the size of the XB-35, the N-9M contributed to the development of the flight data that made the larger, more powerful flying wing possible. The Army Air Force was interested in the project since the flying wing promised natural lift, a shallower profile, and more internal capacity for fuel and weapons. In one test, it demonstrated a significantly reduced radar signature, but no one seemed particularly interested in that characteristic at the time — perhaps because radar itself was a relatively new development in the early 1940’s.

Like the N-1M, the N-9M was modified many times during the course of its flight test program, including experiments with different powerplants and control surfaces. Many flights were frustrating, due to the temperamental technology and the mechanics involved in building a functioning flying wing. The subject of this kit, the N-9MA, was the third N-9 aircraft, and was first flown on May 22, 1944. By November 1944 the test program of some 50 flights was completed, having accumulated a body of data that would lead to the development of the XB-35 and ultimately the jet-powered XB-49.

The first three N-9M’s, including the N-9MA, had Menasco C6S-4 six-cylinder air-cooled in-line piston engines, while the N-9MB was fitted with Franklin eight-cylinder, horizontally opposed O-540-7 engines. As engineering requirements for these aircraft decreased, they were pressed into a training role in which both Northrop test pilots and U.S. Army Air Force would-be XB-35 pilots received flying wing flight training.

Despite the crash of the first N-9M prototype on May 19, 1943, killing test pilot Max Constant, the N-9M was a success in that it led as planned to the XB-35 bomber, which flew for the first time on June 25, 1946. Neither the XB-35 nor the YB-49 went into production, largely because the computer and fly-by-wire technology needed to adequately control the aircraft throughout its flight envelope — including combat conditions — did not yet exist. It was not until 1989, with the first flight of the Northrop Grumman B-2, that the computer control and fly-by-wire technology had evolved to the point that the flying wing bomber as originally envisioned by Jack Northrop was a feasible reality.

Construction

The adventure begins with the resin cockpit, consisting of two detailed sidewalls, which thankfully include painting instructions, a bucket seat with precision recessed detail, main instrument panel, floor, rear bulkhead, and two small, basic parts representing rudder pedals.  The control yoke is unusual in that in does not rise from the floor but extends out from the left sidewall, has its own panel including a small amount of instrumentation, and a bomber style control wheel. The cockpit a painter’s delight, with all the raised and engraved details. However, it does not fit smoothly into the center section of the wing at all – a fair amount of sanding of the resin edges of the final assembly is required for that.

While this is a limited run kit, the plastic is unusually hard; it is denser and more rugged than that found on most kits.  This was not a problem, in fact it lent structural strength that this kit needed.  The next step involved the lower wing center section, involving the inserts for the wheel wells (the smaller well for the rear auxiliary wheel is resin), and the blanking and splitter plate for the two oval-shaped intakes. The positioning of the splitter plates can be tricky, as the modeler’s only guide is the eyeball test. Here I recommend test fittings with Elmer’s Glue until you are satisfied the splitters are in the correct position, as there as no engraved guides in the interior surface of the lower wing to help.

Step 4 is the stage at which the upper and lower sections of the wing center section are cemented together. This will definitely require sanding of the cockpit assembly for a flush fit as noted above, but also the cementing of the pilot’s headrest. Again, there is no rib or guide on the inner surface of the upper wing to guide placement of the headrest, and the instructions are rather imprecise on its exact location – it is important to base your decision on where the cockpit lines up, so that the pilot’s seat and headrest are properly aligned.

At this step the fairings for the propeller shafts are cemented onto the exterior surface of the upper wing, and putty and sanding will be required to hide the seams. I decided to build the N-9 in flight, so I was able to skip Step 5, involving the fitting of the landing gear. Although to my eye this looks more exciting, the kit is not really intended to be built this way, as the landing gear doors did not fit flush into the openings for them in the lower wing center section. There are additional intakes at Step 6 to be fitted to the outboard side of the ventral surface of the wing intakes, perhaps for oil coolers. These two-part assemblies will also require putty and sanding.

The outer wing panels are not unduly complex, consisting simply of upper and lower halves. These parts do not fit smoothly to the wing center section – they are intended to fit over an “inner ledge” that extends out from the center section, but in practice the ledges were a bit thick and required sanding before that fit could be achieved. Even then, putty and sanding were required, and since I was concerned about structural strength for these joins in particular, I broke out the Milliput. After quite a bit of sanding, I had a smooth surface and no visible join seams.

Other than the wings, the vacuform canopy was a challenge, since it had to be made to fit over the cockpit and in a sense “hug” it. I trimmed the rear portion a bit closely and had to cover a small gap with square plastic rod, bent to fit the contour of the cockpit fairing. Initially I planned to affix the canopy to the airframe temporarily with Elmer’s Glue, mask it completely, paint the airframe, then remove the canopy and paint it separately, and finally cement it back on with cyanoacrylate. However as work progressed, I feared that removing it might damage the paint job, so I devised a way to seal the canopy in place with small amounts of Zap-a-Gap applied with the sharpened end of a tooth pick. This worked surprisingly well, and I was able to paint the airframe and the canopy together, then do touch up painting on the canopy afterward.

Painting

The cockpit was painted using Humbrol and Model Master enamels and AK Interactive’s Aluminum for the bucket seat. Most notably, since Northrop’s N-9 MA was a private venture, the sidewalls, floor and rear bulkhead were painted Humbrol Wood, then lacquered with Gunze Sangyo Clear Yellow. Only the pilot’s seat, instrument panel, and control wheel assembly were painted in the colors you would expect for this period (1940’s) – aluminum and flat black, respectively.

Since this was an experimental wartime aircraft and a private venture by Northrop, I felt free to deviate from traditional colors, so long as the basic hues were in the ball park. The upper surface of the flying wing airframe is airbrushed in Tamiya Lemon Yellow, an acrylic gloss. The lower surface is painted Pontiac Engine Blue, from a relatively new line of enamels by a manufacturer called MCW Finishes. While they primarily make car colors, they have a small number of military paints also, and in any event if you are looking for something a little different in an enamel that works extremely well with an airbrush, I highly recommend MCW Finishes.

Conclusion

This kit does not fall together, so it is probably best for intermediate to experienced modelers, based on at least two stages where fit became a major issue – closing the cockpit into the wing center section and cementing on the outer wing sections. The vacuform canopy was also a challenge. That said, it is a fun and rewarding kit, and a joy to behold once its finished. Highly recommended, although as an out-of-production limited run kit it is a darn sight more expensive (about double the price) that when I bought it back in 2014.

References

• The Flying Wings of Jack Northrop by Garry R. Pape with John M. Campbell and Donna Campbell; Copyright 1994 by Schiffer Publishing; Atlglen, Pennsylvania
• www.militaryfactory.com