It was a single bay biplane, with equal span, unswept wings of constant chord and strong stagger, braced with N-form struts and flying wires.

The single seat cockpit, set in an opening in the otherwise continuous, rounded fuselage decking, was under the wing trailing edge where a rectangular cut-out enhanced visibility.

Its tailplane was mounted on top of the fuselage; the fin was quadrant shaped and the straight edged rudder extended down to the keel.

[1] The F.k.45 was powered by a 115 hp (86 kW) Cirrus-Hermes IIB four cylinder inverted air-cooled inline, which drove a two blade propeller.

Its undercarriage was of the fixed, conventional type, with the mainwheels on axles forming an inverted V and attached to the central fuselage underside.