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The Space Shuttle Orbiter is a combination spacecraft and aircraft which can remain in orbit from 7 to 30 d and also fly horizontally and land on existing commercial airport runways. The vehicle utilizes gimballing of the main rocket engines for control during ascent and typical aerodynamic surfaces for control during reentry, approach, and landing. A hydraulic system was selected as the power source for operation of these controls and for actuation of the landing gear, brakes, steering, and jet engine deployment. This paper discusses the system selection rationale, power requirements, flight control characteristics, operational profile, maintenance features, built-in test requirements, and innovative features of the hydraulic system. The system design provides for spacecraft reliability with commercial aircraft serviceability.

The Advanced Fighter Technology Integration (AFTI) program was conceived to provide the mechanism for orderly transfer of Air Force technology programs into operational systems. This paper presents the results of the McDonnell Aircraft Phase I AFTI study, which involved identification of high-payoff, mature technologies, the integration of these technologies into effective operational configurations, the design of manned demonstrator aircraft, and the validation of a selected concept through wind tunnel tests and manned simulation. The Phase I study verified the program premise that fighter/attack aircraft with greatly improved effectiveness are achievable with recently emerged technologies, if these technologies are integrated during the conceptual phase so that they literally shape the vehicle. The Vectored Lift Fighter (VLF) is such a concept, employing new flight and control modes.

State-of-the-art technology developments have enabled the enhancement of an operationally proven, superior weapon system to provide next generation capability. Significant advances applicable to vertical and short take-off and landing (V/STOL) aircraft have been made in aerodynamic, propulsion, composite structure and avionics technologies. These have been incorporated into the AV-8B Weapon System, whose performance has been demonstrated through the YAV-8B prototype flight program.

An interactive graphics system is being used extensively at McDonnell Aircraft Company (MCAIR) for the production design of the F-18 weapon system. Examples are discussed wherein computer graphics has been used in applications varying from preliminary design studies to finished detailing of production part drawings. Structural part definition, mechanism design, clearance and visibility studies, structural analysis and hydraulic system routing are cost-effective applications. Benefits among engineering groups and to downstream users of computer-stored geometry definitions are also discussed.

This paper assesses the state of the art in acoustic fatigue technologies as applied to an advanced supersonic short takeoff and vertical landing (STOVL) aircraft. The topics covered include advanced materials, fatigue, acoustic loads prediction, and stress response prediction. Advanced materials are compared from the standpoints of fatigue resistance and fatigue data availability. State of the art acoustic load prediction techniques are evaluated. Subsonic and supersonic jet noise generation mechanisms, axisymmetric and two-dimensional nozzles, and noise suppression methods are covered. Stress response prediction methods for acoustic, thermal, and maneuvering loads are addressed and the necessity of structural analysis with all three loading types applied simultaneously is assessed.

Aircraft modifications have been developed to make F/A-18D Hornets capable of being converted to a reconnaissance configuration which includes both optical and infrared sensors. A major design challenge was to prevent fog formation on the two exterior moldline windows used for viewing by these sensors. Antifogging was required during a rapid 7620 m/min (25,000 ft/min) descent into humid atmospheric conditions following a sustained cold soak at altitude. This paper describes the design development and laboratory verification testing of the two unique antifog systems selected to meet this requirement.