A comprehensive market survey of the transportation needs both in the helicopter market and the short haul airplane market, revealed a large percentage of potential short haul operations that were limited by available airports and surface distances to their end point destination. The 16H-1 was designed and built to meet this commercial market both in twin and single turbine versions. Other market needs were designed into the machine in order to broaden its sales base (litter stowage, external hoist).
| Type | High Speed Compound Helicopter |
| Crew | 1 |
| Passengers | 4 |
| Engine | UACL PT-6B-2 |
| Horsepower | 550 |
| Rotor Diameter | 41 ft |
| Ducted Propeller Diameter | 5.5 ft |
| Fuselage Length | 25 ft |
| Weight Empty | 2,611 lb |
| Useful Load | 1,589 lb |
| Maximum Speed | 170 mph |
| Cruising Speed | 150 mph |
| Range | 720 miles |
The 16H-1 combines the efficient vertical lift of the helicopter rotor with the higher speed and maneuverability advantages of fixed wing aircraft. This was achieved by adding a wing to unload the rotor in forward flight, and utilizing a tail-mounted ducted propeller, “Ring-Tail”, to provide forward thrust during high speed operation. Thus, the main rotor was unloaded as speed increased, and rotor blade stall and vibration problems of the conventional helicopter were greatly reduce. Directional and anti-torque control during hover and slow flight was accomplished by the ring-tail with deflecting vertical (rudder) vanes in the exit section. Powered by a 405 shp PT6 shaft-turbine engine, the 16H-1 logged a total of 185 flying hours, during which speeds of up to 170 mph were attained.
The 16H-1 evoked interest throughout the military, but their armament and armor needs tripled the gross weight. Convinced that this was the best path for a new attack helicopter, the army initiated a competition for the “Advanced Aerial Fire Support System”, AAFSS, and for supporting technology programs, one of which was the 16H-1A.
