The tow plane “C 3603” was a Swiss multi-purpose combat aircraft of the 1930s and 1940s, it was modernized at the end of the 1960s. The planning and production of the conversion to the “C 3605” type takes place at the Federal Aircraft Works (F+W) in Emmen.

Since the new engine is lighter, the aircraft's center of gravity also changes and adjustments to the shape are necessary. The nose is lengthened and the propeller is located further forward compared to the piston engine version.

The "C 3605" nicknamed Schlepp ("Tug") or "Alpine Anteater", was a target towing aircraft operated by the Swiss Air Force from 1971–1987.