All Ferteteg variants had a plywood-covered, elliptical cross-section, semi-monocoque tapering fuselage. They differed in the increasing width of their cockpits and the more refined canopies of their enclosed, tandem, dual control cockpits. The high mounting of the horizontal tail on the tall, narrow integral fin also changed with the M-30C, which had a lower tail on a long dorsal step. The M-30C also introduced a broader rudder, otherwise like the curved, deep rudders of the earlier versions which reached down to the keel. All variants had similar horizontal tails, trapezoidal in plan out to rounded tips and with elevators requiring only small cut-outs for rudder movement because of their forward position.
