Staff Writer (Updated: 9/7/2014):
The Transall group came to an agreement on an aircraft design centered around a voluminous internal cargo hold accessed via a rear-set, powered loading ramp for ease of operation. This design would be furthered complemented by high-wing loading to help keep the spinning propeller blades clear of ground activity and provide for inherently good short take-off and landing qualities against semi-prepared airstrips. The aircraft could then be charged with carrying supplies, equipment or combat-ready troops (including paratroopers) as needed across ranges out to North Africa. The aircraft would also be blessed with strong low-speed, low-level flight characteristics consistent with the controlled dropping of supply-laden pallets or paratroopers while the aircraft was in-flight. Power would come from a pair of high-output turboprop engines for markedly good operational ranges. To mark their new design, the aircraft took on the conventional "C" designation (for "Cargo", largely accepted in US transport nomenclature), followed by the design's wing area in square meters, this being "160". Therefore, the aircraft was officially given the designation of "C-160".
From the beginning, the joint development effort was signaled by a 50/50 split partnership along national lines with no one concern marked as the principle contractor. The French enjoyed a good level of experience in recent joint-efforts, mostly with the British, when undertaking the Concorde high-speed airliner as well as the SEPECAT Jaguar strike fighter. On the other hand, the Germans lacked such knowledge - in part to an aviation engineering force still establishing itself after the demilitarization of Germany following World War 2 - and were limited to manufacture of basic transport aircraft. Nord would be given production control of the engine nacelles, wings and undercarriage control systems while Hamburger would produce the forward and aft sections of the fuselage, the all-important powered loading door and the vertical tail fin. Weser was given manufacture rights to the landing gear door panels and center fuselage/wing root sections. The engine of choice became the Rolls-Royce Tyne 20 Mk 22 turboprop engine of 6,100 shaft horsepower - already being built under license in France by Hispano-Suiza.
Design-wise, the appearance of the C-160 was highly conventional and not unlike the Lockheed C-130 Hercules mount. Construction is of all-metal with a semi-monocoque internal frame. The fuselage was stout and tubular - flattened only along the bottom facing - with the flight deck fitted forward behind a short nose cone assembly offering excellent views out of the cockpit. Doors were fitted to either side of the rear fuselage for paratrooper drops or passenger entry/exit. The wings were set ahead of center mass and high-mounted for maximum ground clearance as well as strong lift characteristics. The wing assemblies featured no sweep of any kind and were clipped at the tips. The twin engine pairing were fitted within streamlined nacelles along the wing leading edges, each engine sporting four-bladed propeller systems. The empennage was specifically designed to taper upwards and provide unfettered access to the rear loading ramp. The loading ramp was designed as a two-piece system with the main ramp floor lowering down to the height of a standard truck bed. The upper empennage section then rose to help improve overhead clearance. The cargo bed floor was fully reinforced to support nearly all manner of supplies and equipment - including light vehicles - conforming to the specified weight limits. An integrated winch system assisted in bringing heavy loads aboard. Up to 93 seats could be installed within the cargo hold for the transporting of passengers while 60 to 88 combat-ready troops could be seated in their place (their equipment taking up the rest of the space). Alternately, 62 medical litters and corresponding medical personnel could be carried. The tail section was capped by a single, large-area vertical tail fin with a pair of horizontal tailplanes fitted to its base. The low-set undercarriage was fully retractable and consisted of a pair of four-wheeled main landing gears as well as a twin-wheeled nose landing gear leg. The main legs were held in underfuselage sponsons at the center of the design while the nose leg retracted under the flight deck floor. The wheel's low-pressure nature made them suitable for rough field operations.
Initial flight of the first of three prototypes was accomplished on February 25th, 1963 out of Melun in France. The remaining two prototypes then each went airborne later that year and two static test frames were also delivered. Early production of the aircraft began in 1965 resulting in six pre-series "C-160A" model aircraft. Upon completion of evaluations and formal acceptance into service, serial production of the C-160 began in 1967, this being shared equally between the participating parties across West Germany and France - of note being that no one facility or nation produced each aircraft in whole, each being dependent upon the other for the final end-product.