The Soloy Pathfinder 21 was a conversion of a Cessna 208B powered by the Soloy Dual Pac (two side-by-side P & W PT-6 engines driving a single propeller) developed with Pratt & Whitney Canada. A 72 inch fuselage extension aft of the wing and extra capacity for cargo or baggage under the fuselage were other modifications. Soloy abandoned the program when the FAA required it be certified under FAR 25 (Transport category) requiring higher airframe strength that would be too expensive if not impossible to implement.