Yokosuka MXY3 target glider on top of a Kawanishi E7K1 "Alf" floatplane
For a long period, the Imperial Japanese Navy employed only streamers as aerial targets. However, in the autumn of 1937, it was proposed to utilise gliders as targets for anti-aircraft gunnery training. Under the guidance of Engineer Yamana Masao, the prototype was developed by the Aircraft Division of the Naval Air Arsenal with Engineer Yamamoto Haruyuki as chief designer. A frame was constructed atop the wings of a Kawanishi E7K "Alf" floatplane, attaching a bomb release mechanism facing upwards. The target glider was placed on this frame, designed to detach at the required altitude and glide straight ahead for as long as possible. The first prototype underwent detachment test flights at the mouth of Tokyo Bay in early 1938. Subsequently, aircraft built at the Chigasaki Works exhibited variations in stability and lacked straight-line tracking. This issue was resolved by equipping the fuselage with a control system (for the rudder) utilising the gyro-type steering mechanism from torpedoes as autopilot system. The cruising speed was 85 kt (157.4 km/h). The MXY3 modified type was redesigned with a flat elliptical cross-section fuselage and painted yellow to ensure visibility for the gunner. Production initially took place at the Chigasaki Works, later at Kawai Musical Instruments in Hamamatsu, but proved cumbersome to fly and yielded poor training results relative to effort. Furthermore, as one aircraft was discarded after each use, it was not employed for long and was not formally adopted. Approximately 30 units were produced.
Yokosuka MXY4 target glider on top of a Kawanishi E7K2 "Alf" floatplane
In 1940, following the MXY3 gliding target aircraft, a radio-controlled powered target aircraft was requested for the Combined Fleet's anti-aircraft gunnery training.
At the Naval Air Arsenal, Engineer Haruyuki Yamamoto was again appointed chief engineer. A prototype was developed by enlarging the MXY3, equipping it with an AVA-4H 32EP engine and twin pontoons. Like the MXY3, this aircraft used the Kawanishi E7K "Alf" floatplane as its carrier. It detached at an altitude of approximately 3,000 metres and a speed of 65 knots. After detachment, it performed powered flight via radio control at the same altitude. If high-angle shells failed to hit it, it would glide to a sea landing for recovery.
Following preliminary and operational trials off Yokosuka and in Saeki Bay, the aircraft was adopted for use as a training target for the Combined Fleet. Initially designated the "Type 1 Target Drone", it was later designated the "Type 1 Target Drone Model 11". Formal adoption occurred in May 1942. Production took place at the Mizuno Glider Manufacturing Works in Osaka, with the cooperation of engineers Maeda Kenichi and Kimura Kan'ichi. Later, production also commenced at Toyo Metal and Woodworking in Itami. The engine fitted was the "Semi Type 11", a domesticated version of the French AVA-4H air-cooled, horizontally opposed four-cylinder engine, originally intended for the "Hibari" type light aircraft (Pou du Ciel).
This aircraft can be considered a precursor to today's target planes. It was highly practical, and with further development, it showed promise as a ground-attack guided missile. Initially, the requirement for a fuselage size comparable to a fighter made it somewhat oversized for a target drone, but its radio controllability was good, and it can be considered a success. Later, it gained attention as one of the items proposed by the Japanese side in technical exchanges with Germany. However, as the war intensified, it gradually fell out of use.
In the MXY series of research experimental aircraft and special gliders developed at the Naval Air Arsenal (established in 1932) and the Naval Air Technical Arsenal (established in October 1941), M denotes special aircraft, X denotes prototype, Y denotes Yokosuka Air Arsenal/Air Technical Arsenal.