07/31/2013. Remarks by Walter van Tilborg and Johan Visschedijk: "In 1930 Belford D. Maule of Jackson, Michigan, USA built the M-1 (NC12634 c/n M-1) mid-wing single-seat monoplane, with a 27 hp Henderson motorcycle engine. In 1940 he founded the Mechanical Products Company, that was changed to B.D. Maule Company in 1941, producing light aircraft ventilation units and tail wheel assemblies. In 1944 the M-2 (NC34105 c/n M-2) single-seat ornithopter was completed in 1944. In 1962 Maule Aircraft Corporation was formed to develop, certificate and produce the Maule M-4 Bee Dee.

The M-4 Bee Dee was a classic steel tube and fabric high-wing light aircraft with a fixed tail wheel landing gear. The prototype M-4 was first flown in February, 1957 and Maule intended that it would meet customer demand from those who preferred conventional fabric covered aircraft to those all-metal designs which were beginning to appear. In fact, the M-4 is covered in 'Razorback' glass fiber material and is, therefore, more durable than most traditional fabric covered types.

The M-4 received its type certificate on August 10, 1961 and went into production at Jackson, Michigan powered by a Continental O-300A engine. It provided full four-seat capacity with very favorable short field performance. The M-4 airframe was then developed by installing a variety of power plants and airframe modifications.

The fuselage was altered to include a cargo door on the rear starboard side and machines with this feature have a 'C' as a suffix to the designation (e.g. M-4-21OC). They also produced a two-seat trainer which had 'T' as a designation suffix and had no rear seating or rear door. However, Maule built only two further aircraft and did not produce the proposed 180 hp, 210 hp or 220 hp versions. In addition, the specially equipped M-4S was also produced, but only three examples were flown. The M-4 was also certificated for operation on floats.

In 1963, an arrangement was set up for license production in Mexico by Servicios Aereas de America S.A., designated M-1 Cuauhtemoc. Full details of the produced 474 M-4s are:

M-4 Bee Dee. Basic four-seat high wing light aircraft with fixed tail wheel landing gear and 2,100 lb (953 kg) TOGW, with 145 hp Continental O-300A engine. Introduced 1962. Prototype N40001 (c/n 1), 94 produced (c/n 1 to 94).
M-4C Jetasen. M-4 with cargo door. Prototype N9827M (c/n 1C), eleven produced (c/n 1C to 11C).
M-4S. M-4 'Standard' with upgraded equipment. Prototype N9834M (c/n 1S), three produced (c/n 1S to 3S).
M-4T. Dual-control trainer M-4 without rear seats or rear entry door. Prototype N9822M (c/n 1T), three produced (c/n 1T to 3T).
M-4-180C Astro Rocket. M-4C with 180 hp FrankIin 6A-335-B1A engine. 2,300 lb (1,043 kg) TOGW introduced for this and all models with 180 hp or higher, seven produced (c/n 3001C to 3007C).
M-4-210 Rocket. M-4 with 210 hp Continental IO-360A engine, 45 produced (c/n 1001 to 1045).
M-4-210C Rocket. M-4-210 with cargo door, 117 produced (c/n 1001C to 1117C).
M-4-220C Strata Rocket. M-4C with 220 hp Franklin 6A-350-C1 engine, 190 produced (c/n 2001C to 2190C).
M-4-22OS. M-4S with 220 hp Franklin 6A-35O-C1 engine, one produced (c/n 2001S).
M-1 Cuauhtemoc. Standard M-4 with 180 hp Lycoming O-360 engine, three produced (c/n 101 to 103)."