February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 1 Acoustic Panel Delamination February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 2 CFM56-7B IDG Acoustic Panel Rupture Background • Several cases of IDG panel failure on CFM56-7B Engines reported • Failure discovered with lowest operational time at 1,500 hrs / 500 cycles Acoustic Panel Delamination February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 3 Investigation status • Mechanical potting characteristics decrease through temperature and aging phenomenon • Cracks beginning in the Honeycomb following by cut out of the outer skin then tearing of the inner skin layer • Phenomenon generated by vibratory excitation CFM Recommendation • Panel to be removed when found cracked • 500 cycles Service Extension allowed with panel removed (AMM72-23-02 Jun, 2001) CFM56-7B IDG Acoustic Panel Rupture Acoustic Panel Delamination February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 4 Corrective Actions • Design improvement Upper and inner skins material changed to increase temperature characteristics : From 120°C to 180°C Panel Potting change for better behavior in high temperature environment conditions : From Minnesota to E3439 Manufacturing process changed to increase hole edge strength Design finalized, to be approved by Agencies Apr 02 Implementation in production Jul 02 CFM56-7B IDG Acoustic Panel Rupture Acoustic Panel Delamination作者: kinran 时间: 2011-6-4 23:23:27
