[8] Its 130 kW (180 hp), air-cooled, inverted six-cylinder inline Regnier R 6[7] was in the nose, driving a two blade, variable pitch propeller and with its fuel stored in the fuselage.

The seats were enclosed under continuous multi-panel glazing which ran unbroken into the raised top of the rear fuselage, coupé fashion.

[8] The rear surfaces were constructed like the wings; the tailplane, attached halfway up the fuselage, could be adjusted on the ground and carried elevators with cut-outs for movement of a rounded, unbalanced rudder which reached down to the keel.

Both designs had mainwheels on vertical legs from the outer part of the wing inner section but the earlier model also had diagonal V-struts from axles to lower fuselage,[3] whereas those of the Maillet 20 were cantilevers, without struttage.

[10] The Armée de l'Air bought 30 examples of a very similar trainer version,[12] fitted with automatic two speed propellers,[13] designated the Maillet 201.

The pilot's seat was raised with a clear forward view through a small windscreen in a head-wide, faired, part glazed dorsal enclosure.

[18] In the first Hélène Boucher Cup race for female pilots, contested on 31 August 1935, Claire Roman finished second in a Maillet 21.