Approved for public release, distribution is unlimited / The J-52 engine used in the EA-6B Prowler has been found to have a faulty design which has led to in-flight engine failures due to the degradation of the 4.5 roller bearing. Because of cost constraints, the Navy developed a policy of maintaining rather than replacing the faulty engine with a re-designed engine. With an increase in Prowler crashes related to the failure of this bearing, the Navy has begun to re-evaluate this policy. This thesis analyzed the problem using methods in reliability statistics to develop policy recommendations for the Navy. One method analyzed the individual times to failure of the bearings and fit the data to a known distribution. Using this distribution, we estimated lower confidence bounds for the time which 0.0001% of the bearings are expected to fail, finding it was below fifty hours. Such calculations can be used to form maintenance and replacement policies. Another approach analyzed oil samples taken from the J-52 engine. The oil samples contain particles of different metals that compose the 4.5 roller bearing. Linear regression, classification and regression trees, and discriminant analysis were used to determine that molybdenum and vanadium levels are good indicators of when a bearing is near failure. / http://hdl.handle.net/10945/945 / Ensign, United States Navy
| Identifer | oai:union.ndltd.org:nps.edu/oai:calhoun.nps.edu:10945/945 |
| Date | 06 1900 |
| Creators | Muller, Cole |
| Contributors | Olwell, David H., Buttrey, Samuel E., Naval Postgraduate School (U.S.), Department of Operations Research |
| Publisher | Monterey, California. Naval Postgraduate School |
| Source Sets | Naval Postgraduate School |
| Detected Language | English |
| Type | Thesis |
| Format | xiv, 67 p. : ill. (some col.) ;, application/pdf |
| Rights | This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, may not be copyrighted. |
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