Accession Number:

ADA455914

Title:

Failure Analysis of a Cracked CH-47 Swashplate Rotating Ring, S/N BCW-1379

Descriptive Note:

Final rept. 1 Jan-1 Mar 2005

Corporate Author:

ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE

Personal Author(s):

Report Date:

2006-06-01

Pagination or Media Count:

28.0

Abstract:

The U.S. Aviation and Missile Command sent the U.S. Army Research Laboratory s Weapons and Materials Research Directorate three swashplate rotating rings from the CH-47 helicopter for investigation. The components were examined due to the presence of cracks found during routine overhaul. These cracks were on and adjacent to the bearing retention shoulder. One of these rotating rings, SN BCW-1379, was included for a detailed failure analysis to determine the cause of the cracking. This component was QDR exhibit number W45N7V-04-0307. The components were required to be forged from aluminum alloy 2014-T6. The focus of this investigation, BCW-1379, was characterized by nondestructive inspection, chemical analysis, optical microscopy, scanning electron microscopy, and mechanical testing. The holes of the rotating ring were numbered 0 36 around the perimeter, consistent with the convention of the MELRs from Boeing helicopters.

Subject Categories:

  • Helicopters
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE