Accession Number : AD0768843

Title :   U. S. Army Helicopter Rod End Bearing Reliability and Maintainability Investigation

Descriptive Note : Final rept.

Corporate Author : SYSTEMS ASSOCIATES INC LONG BEACH CA

Personal Author(s) : Dockswell, Sheldon ; Huffman, James L

PDF Url : AD0768843

Report Date : Jun 1973

Pagination or Media Count : 124

Abstract : The investigation was carried out to identify, isolate, and verify the causes of problems with rod end bearings (REB) used on U.S. Army helicopters and to trace the resulting effects on helicopter availability. Design requirements, quality assurance provisions, maintenance procedures and practices, test requirements, and procurement practices were analyzed to assess their impact upon the current problems. Excessive play between ball and race was found to be the REB's chief failure mode. Design does not adequately contend with a vibratory environment which tends to cause widening of the race. Quality assurance was neither imposed upon the bearing vendors nor demonstrated by airframe manufacturers. A recommendation was made for a specification to be developed to govern existing or new designs, which include a stainless steel ball with a ceramic coating and a graphite race, a slotted spherical bearing, and an elastomeric spherical bearing. The recommended specification for helicopter REB's includes bond and material integrity, loading, vibration, dust, misalignment angle, qualification and conformity requirements. Specific recommendations for improvements to the policies, practices, and procedures are made in the report; hardware improvements are also discussed.

Descriptors :   *BEARINGS, *HELICOPTERS, ACTUATORS, AIRFRAMES, ALIGNMENT, ARMY AIRCRAFT, CERAMIC MATERIALS, COSTS, FAILURE(MECHANICS), MAINTENANCE, QUALITY CONTROL, VIBRATION

Subject Categories : Helicopters
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE