The Merlin III is a twin engine aircraft built by Fairchild Aircraft Corporation. The aircraft is powered by two turboprop engines equipped with constant speed, full feathering, reversible propellers. The engines are built by Garrett Air Research and are rated at 850 shaft horsepower each. The cabin is pressurized, heated and cooled by engine bleed air, which is directed through valves, heat exchangers and refrigeration units.
The aircraft was modified by the installation of flight test engineer consoles and flight test instrumentation. The interior configuration can accommodate a flight crew of two and six students seated in bench seats at two separate consoles in the aircraft.