308 research outputs found

    Aeronautical Engineering: A special bibliography, supplement 60

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    This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

    Full-scale transmission testing to evaluate advanced lubricants

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    Experimental tests were performed on the OH-58A helicopter main rotor transmission in the NASA Lewis 500 hp helicopter transmission test stand. The testing was part of a lubrication program. The objectives are to develop and show a separate lubricant for gearboxes with improved performance in life and load carrying capacity. The goal was to develop a testing procedure to fail certain transmission components using a MIL-L-23699 based reference oil and then to run identical tests with improved lubricants and show improved performance. The tests were directed at parts that failed due to marginal lubrication from Navy field experience. These failures included mast shaft bearing micropitting, sun gear and planet bearing fatigue, and spiral bevel gear scoring. A variety of tests were performed and over 900 hrs of total run time accumulated for these tests. Some success was achieved in developing a testing procedure to produce sun gear and planet bearing fatigue failures. Only marginal success was achieved in producing mast shaft bearing micropitting and spiral bevel gear scoring

    Aeronautical Engineering: A special bibliography with indexes, supplement 55

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    This bibliography lists 260 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1975

    Aeronautical engineering: A continuing bibliography with indexes (supplement 233)

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    This bibliography lists 637 reports, articles, and other documents introduced into the NASA scientific and technical information system in November, 1988. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

    Benefits assessment of active control technology and related cockpit technology for rotorcraft

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    Two main-rotor active control concepts, one incorporating multicyclic actuators located just below the swashplate, and the other providing for the actuators and power supplies to be located in the rotating frame are considered. Each design concept is integrated with cockpit controllers and displays appropriate to the actuation concept in each case. The benefits of applying the defined ACT/RCT concepts to rotorcraft are quantified by comparison to the baseline model 412 helicopter. These benefits include, in the case of one active control concept; (1) up to 91% reduction in 4/rev hub shears; (2) a flight safety failure rate of 1.96 x 10 to the 8th power failures per flight-hour; (3) rotating controls/rotor hub drag reduction of 40%; (4) a 9% reduction in control system weight; and (5) vibratory deicing. The related cockpit concept reduces pilot workload for critical mission segments as much as 178% visual and 25% manual

    Aeronautical engineering: A continuing bibliography with indexes, supplement 190

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    This bibliography lists 510 reports, articles and other documents introduced into the NASA scientific and technical information system in July 1985

    Aeronautical Engineering: A continuing bibliography with indexes

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    This bibliography lists 382 reports, articles and other documents introduced into the NASA scientific and technical information system in June 1982

    Development of a full-scale transmission testing procedure to evaluate advanced lubricants

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    Experimental tests were performed on the OH-58A helicopter main rotor transmission in the NASA Lewis 500-hp Helicopter Transmission Test Stand. The testing was part of a joint Navy/NASA/Army lubrication program. The objective of the program was to develop a separate lubricant for gearboxes and demonstrate an improved performance in life and load-carrying capacity. The goal of the experiments was to develop a testing procedure to fail certain transmission components using a MIL-L-23699 base reference oil, then run identical tests with improved lubricants and demonstrate performance. The tests were directed at failing components that the Navy has had problems with due to marginal lubrication. These failures included mast shaft bearing micropitting, sun gear and planet bearing fatigue, and spiral bevel gear scoring. A variety of tests were performed and over 900 hours of total run time accumulated for these tests. Some success was achieved in developing a testing procedure to produce sun gear and planet bearing fatigue failures. Only marginal success was achieved in producing mast shaft bearing micropitting and spiral bevel gear scoring

    Aeronautical Engineering: A continuing bibliography with indexes (supplement 166)

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    This bibliography lists 558 reports, articles and other documents introduced into the NASA scientific and technical information system in September 1983

    Aeronautical engineering: A continuing bibliography with indexes (supplement 204)

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    This bibliography lists 419 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1986
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