1/72 AMT XB-35

Flying Wing Bomber

by Terry Chan

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Although it was not his original concept, Jack Northrop was probably the biggest proponent of the flying wing design, of which the airframe without a discernible fuselage houses its crew, fuel, engines and payload entirely within a thick wing structure.
 
The development of the long range Northrop XB-35 bomber started in 1941.  It made its first flight in 1946.  The radical all-wing design presented many technical challenges, most notably stability issues.  The XB did not meet the range, speed and payload specifications, and the gearboxes of the contra-rotating propellers also brought a lot of problems.  Eventually they were replaced with conventional propellers (designated YB-35), which even further impacted its speed and range negatively.
 
Before it even had the chance to resolve all these problems, the X/YB-35 became obsolete as the post-war era ushered in rapid adoption of jet engines for military use.  The jet version of the flying wing bomber YB-49 was introduced, which was eventually cancelled in favour of more conventional and reliable aircraft designs.  The inherent stability problems of the all-wing design were not fully resolved until the introduction of "fly-by-wire" technologies enabled by mirco processors.  The B-2 Spirit stealth bomber, itself also an all wing design by Northrop, is a great example.

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This kit is one of AMT/ERTL's last kits before it ran out of business.  It's still relatively easy to find, although you don't see it built very often.  As usual, construction started with the cockpit.  This is probably the most detailed stock 1/72 cockpit I've built, easily surpassing a lot of 1/48 cockpits in terms of molded detail.  It includes all the seats for the 5 crew members, raised detail for the pilot instrument panels, radar operator panel, and gunner periscope.  Unfortunately most of the detail will be buried deep inside the thick wing body once assembled.  I added some fishing weights at the nose to prevent tail-sitting.
The engineering of the airframe is quite simple: there are the top and bottom umm, fuselage halves; each wing tip are two pieces; the leading edges are separate pieces.  Considerable amount of filling and sanding was needed on most of the parts to get them fit nicely together, especially on the bottom side of the leading edges where 8x engine exhaust "domes" are.  There are four engines, each comprise of three pieces plus the propeller pieces.  Since I opted for the XB-35 option (you can build either XB or YB), I had 2 x4 x2 = 32 propellers in total!  All of them needed to be painted yellow and black and masked prior to the metallic paint for the spinners.    It was tedious work, but doable in a couple of days.
 

After main construction was completed, I sprayed a coat of automotive primer over the airframe and polished it with 1500 and 2000 grit sandpaper.  I used 5 different shades of Alclad (aluminum. white aluminum, dark aluminum, and two custom shades) to achieve the multi-paneling effect.  To my dismay, the primer that I used resulted in some almost microscopic crazing of the plastic, which made some areas of the Alclad finish unsatisfactory.  I ended up sanding off the paint on some smaller affected area and repainting sessions ensued.  The end result is still not perfect, but I've learned to live with imperfect models that I built in the past, so I'm sure I'll get over this one. 

The landing gears and gear doors were attached after painting.  The main gears were very strong and sturdy, but the nose gear was less so.  I used the kit decals even though they have yellowed badly.  They still adhere well and are usable after I trimmed off the carrier film.

The finished model is big, impressive, and will definitely garner a lot of attention.  I'm glad I stuck with it after the primer mishap because it really is a beautiful model and I enjoyed building it.  It is now on display at Toronto's Aviation World.  I have another copy of this model in my stash, and I hope to build a better version with the experience learned from this one under my belt.

Terry

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Photos and text © by Terry Chan