Acoustic Panel Delamination

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Acoustic Panel Delamination

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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