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A two-engine, three-fan V/STOL airplane was designed to fulfill naval operational missions. Use of interconnected variable pitch fans led to a good balance between the requirements for high thrust and responsive control at low speed, and efficient thrust at cruise speeds. Engine-out requirements, integration of propulsion and aerodynamic controls, and the propulsion installation were the major factors influencing the configuration. An airplane with a multimission capability from both vertical and short takeoff was conceived.

Aircraft manufacturers spend millions of dollars reworking blown fastener holes, especially in portable tool drilling situations. Oval, tapered, rifled, and oversize holes are costly rework issues currently commonplace in the industry. The most common causes of imperfectly drilled holes include spindle runout, insufficient clamp and feed force, out-of-balance drill feed forces, spindle windup, and lack of adequate feed control. This paper will focus on a next-generation drilling machine that utilizes a unique combination of hydraulics and pneumatics to solve the problems associated with legacy drilling units. Several design elements will be examined, such as the use of an on-board, 1000 PSI hydraulic pump, controlling both drill feed and clamp force. This greatly reduces the size and weight of the clamp and feed cylinders compared to legacy air systems, while increasing their force and rigidity.