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The testing of a titanium matrix composite (TMC) F-15 nose gear outer cylinder is discussed. Two cylinders were fabricated. An entire F-15 nose gear was assembled using the first cylinder. This test gear underwent static structural tests to three critical loading conditions and functional evaluations including load-stroke, rebound snubbing, jig drops and strut stroke cycling. The TMC cylinder successfully completed both groups of testing with no signs of structural or functional degradation.

Numerical simulations indicate that blast loading on aircraft structural joints can impart loading rates in excess of 10 Mlb/sec (ten million pounds per second, Reference 1). Experimental evidence, on the other hand, suggests that mechanical joint failure loads are highly loading rate dependent; for example, the failure load for a dynamically loaded tension joint can double from its static value. This paper discusses the progress and to-date findings of research on the assessment of strength failure of aircraft structural joints subjected to loading rates expected from an internal explosive detonation, and several associated experimental procedures to generate such dynamic loading. This work is conducted at MDC and at the University of Dayton Research Institute (UDRI) in support of the FAA Aircraft Hardening Program.

The U.S. Air Force has recognized the need for an alternative to the conventional hydraulic brake system. Hazards associated with fires and the maintenance required for a hydraulically actuated system are the principal drawbacks of hydraulic brake systems. In addition, an alternative brake system will be required to support a “More Electric” aircraft of the future. The solution to these problems was provided by the “Electrically Actuated Brake Technology (ELABRAT)” program, a three year program sponsored by the Flight Dynamics Directorate at Wright Patterson AFB. ELABRAT developed and demonstrated an Electromechanically Actuated (EMA) brake system to replace the existing hydraulically actuated piston housing and associated hydraulic control hardware.

Pivot point concepts for fighter type aircraft with variable sweep wings are reviewed. Structural and aerodynamic considerations involved in sweep pivot location, a summary of endurance testing of Teflon lined journal bearings, and variation of fatigue life of the aircraft versus wing sweep position are discussed.

Effects which normally diminish the value of a manually flown instrument approach are examined in the light of flight test results with the Head-Up Display (HUD). It is possible to avoid shortsightedness (space myopia) and disorientation phenomena associated with poor external visibility, by choice of display position and format, allowing an efficient alternation between display and forward view. The display can also be designed to fit the man, in both static and dynamic characteristics, with benefits of rapid learning and accurate tracking. These results remove the basis for supposing man's intervention in the all-weather landing to be disastrous. On the other hand, man's participation may be necessary, because more information is connected with a safe approach than can be dealt with by an unaided machine. Synthesis of an automatic system with HUD may turn out to be the most acceptable solution to the overall problem of all-weather operation.

Heat powered ECS concepts using a Rankine or Stirling power cycle to drive a vapor compression refrigeration cycle were evaluated for future fighter aircraft. Arrangements with separated power cycle and refrigeration cycle working fluids were considered, as were arrangements combining these cycles via a common working fluid. Promising heat sources and working fluids for these concepts were identified. Haste heat sources in the propulsion system and airframe were compared with regard to heat capacity, temperature level, and collection system design complexity. A screening process, which distinguished between the requirements imposed by the power cycle and refrigeration cycle, was developed to select promising working fluids. Concepts were evaluated using various system arrangements, heat sources, and working fluids to minimize the ECS-related TOGW penalty.

While the results of an exploding (bursting) tire have long been recognized as catastrophic to personnel and surrounding equipment, little work has previously been performed to quantify the tire burst phenomena. Using the Wright Laboratory Landing Gear Development Facility at Wright Patterson Air Force Base, the pressure wave released by a bursting tire was investigated as part of the United States Air Force sponsored Extended Life Tire program. This evaluation included pneumatic blowouts of F- 16 Block 30 (25.0>x8.0-14) and B-52 (56x16) main landing gear tires. The results of this testing are detailed in this paper and include the identification of: shock wave propagation, attenuation, and distribution, the potential effects on personnel, and recommendations for analysis / prediction techniques.