In 1935, the Imperial Japanese Navy drew up the 10-shi specification for a modern torpedo aircraft to replace its biplane carrier bombers. The specification had certain practical requirements: room for a three-man crew, wingspan less than 16 meters, speed above 205 mph, endurance at cruising speed greater than four hours, and the plane had to be able to haul a 1764-pound ordnance load.

Nakajima took this specification and developed the B5N "Kate," one of the three great torpedo bombers of World War II. Mitsubishi used ideas gleaned from study of a Northrop 5A bomber to develop a much more conventional answer to the same problem. The B5M1 rested its bulk on a pair of fixed, spatted landing gear. Its broad elliptical wing mimicked that of the A5M "Claude" fighter. The immense greenhouse canopy blended into the fuselage just ahead of the tail, giving the plane the look of a scaled-up Ki-15. The combination of all these features made the B5M1 appear immensely cumbersome in comparison to the B5N1, and it weighed in at over 500 pounds heavier than the "Kate." Despite this, the B5M1's top speed was two miles an hour faster than the "Kate's" and maximum range was over 130 miles greater.

Other factors sealed the B5M1's fate. Tests in November 1937 showed the "Kate" to be more maneuverable, and the long, lean B5N1 looked the part more than the B5M1. Even though the B5N1 was deemed the winner and ordered into production, problems with the advanced systems of the "Kate"--most notably a recurring failure of the hydraulic undercarriage retraction system--meant that the B5M1 went into production as an insurance measure. Eventually, 125 aircraft were manufactured. When war came, the B5M1 received the identifying name of "Mabel" from the allies and orders to bases in China, Hainan and Indochina from the Japanese command. Their service careers were brief, and by 1943 all surviving "Mabels" were living out their days as training aircraft.

The AML kit of the "Mabel" consists of 77 injection-mold pieces, two vacuformed canopies, a sheet of printed instruments and decals of one plane serving with an unidentified unit in China. As is the case with most short-run kits, the large components are very well executed, with petite scribing. The finer pieces, however, are soft in detail, and the entire kit is replete in flash. Luckily, the majority of the small parts are for various ordnance load outs; the kit provides you with an option of a torpedo, a single 800kg (1734 lbs.) bomb or six 60kg bombs. These smaller weapons are mounted on external pylons and each rests on a pair of sway braces.

The interior is somewhat rough, though AML tries to provide a head start. The instrument panels are represented with raised disks for the instruments; the instructions would have you place the printed panels over these, an unlikely prospect. The rear cockpit radio would have looked convincing if not for a large sinkmark that gives an impression of what would have happened if Salvador Dali had worked for Sony. The seats are simple, with no seat belts, and the floorboard is a note-for-note copy of the floor provided in the Mania (now Hasegawa) kit of the B5N2 Kate! These similarities mean that some creativity and the use of a detail set for the Kate could be used to bring the Mabel's interior up to snuff.

The Kinsei 43 radial is molded in two parts, with push rods and wiring detail present, but the copious amount of flash makes this a candidate for replacement a well.

The rest of the aircraft assembles in straightforward fashion. The wheel spats come in halves, with separate wheels. Injection-molded control horns--three for each wing--might better be represented with bits of wire, as cleaning up the kit parts could be a challenge. The propeller and wing-tip mass balances might better be stolen from the parts box as well.

The vacuform canopies are perhaps the most remarkable parts of the kit. They are two and a half inches long and very clear, with the many frames clearly delineated. This feature should help when it comes time to mask the transparencies.

The decals are simple—just hinomarus, propeller warning stripes and the tail code "33-305"—for one green-over-gray aircraft.