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F-15 Nose Landing Gear Shimmy, Taxi Test and Correlative Analyses
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 01, 1980 by SAE International in United States
Annotation ability available
F-15 taxi tests and analyses were performed to evaluate the effects of aircraft design changes on nose landing gear shimmy. Preliminary analytical studies indicated that these changes would have an adverse effect on shimmy speed. This was of particular concern because limit cycle shimmy had been experienced on the baseline gear for cases with out-of-tolerance strut torsional freeplay. The tradeoffs considered in the choice of a taxi test over a laboratory dynamometer test are presented. Operational aspects of the taxi test are discussed. Several instances of limit cycle shimmy were encountered during testing and results indicate that shimmy speed is a function of strut torsional freeplay. A description of the math model used in the non-linear analyses is provided. Analytical results are presented in terms of shimmy speed versus strut torsional freeplay. These results confirm the limit cycle nature of the shimmy phenomenon and correlate well with the taxi test results. Additional analyses are presented indicating the sensitivity of the shimmy to changes in tire parameter values and strut frictional coefficients. Assumptions used in the development of an equivalent linear math model are given.
CitationGrossman, D., "F-15 Nose Landing Gear Shimmy, Taxi Test and Correlative Analyses," SAE Technical Paper 801239, 1980, https://doi.org/10.4271/801239.
- Black R. J. “Realistic Evaluation of Landing Gear Shimmy Stabilization by Test and Analysis” SAE Paper No. 760496 April 1976 TRANSACTIONS OF THE SAE 85 1976 1695 1708
- Southerland K. F. “Shimmy Analysis for the F-15 Nose Landing Gear Report” McDonnell Aircraft Company Report MDC A0932 March 1971
- Black R. J “Empirical Estimation of Tire Parameters” SAE A-5 Committee Meeting Seattle, Wash., Spring 1980
- Collins R. L. Black R. J. “Experimental Determination of Tire Parameters for Aircraft Landing Gear Shimmy Stability Studies” AIAA 68-311” April 1968
- Collins R. L. Black R. J. “Tire Parameters for Landing Gear Shimmy Studies” AIAA JOURNAL OF AIRCRAFT 6 3 May June 1969 252 258