CFM EMCD Failure

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EMCD
Failure
CFM56 Operators Conference – May 21 - 22, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 2
EMCD System
Visual Indicator
Master Chip Detector
CFM56 Operators Conference – May 21 - 22, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 3
• Reports of MCD contamination not setting Visual Indicator
pop-out
- P/N: 301-779-401-0
- Vendor: IN-LHC (Vendor P/N: 125A3)
- Visual indicator TSN/CSN= 3817/4756
Fleet Experience
CFM56 Operators Conference – May 21 - 22, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 4
Interim Field Plan
• On-wing EMCD system inspection
- Inspection SB 72-0414, cat 2, issued Oct. 2001
-On-wing procedure to check EMCD system (Magnet Chip
Detector and Visual Indicator) functionality
- To be performed at first opportunity then every “A” check
- Inspection task 79-20-00-C8 to be incorporated in MRB/MPD
-MPD incorporation planned 4th qtr 2002
- Aircraft MEL modification in process
• Current SB 72-0414 report status
- 14 removals vs 273 inspected
- 10 confirmed defective
CFM56 Operators Conference – May 21 - 22, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 5
Investigation At Vendor
• Magnet piston wear root cause identified
- Silica residue degrades Microflon coating
- Silica residues inherent to sand blast cleaning prior to Microflon coating
- Inappropriate anticorrosion oil applied during manufacturing
Moving Magnet
Piston
Solenoid
Area of wear
CFM56 Operators Conference – May 21 - 22, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 6
Corrective Actions
• Piston manufacturing audit performed
- Deletion of anticorrosion mineral oil spray: Oct. 2001
- From S/N YU061816
- No substitute require
- Affected population
- Visual Indicators (927 units)
- Manufactured from Sept. 97 to Dec. 01
- From S/N 10375 to S/N YU061815.
• CFM monitoring removals to assess further field actions
- One high time Visual Indicator found stuck due to heavy piston
wear.....not included in affected population
CFM56 Operators Conference – May 21 - 22, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 7
• Objectives
- Decrease spurious pop-outs
- No Magnet Chip Detector change
- Interchangeability not affected
• Visual Indicator design changes
- Desensitized...reduced electrical threshold from 2K to 130
- 10 sec delay before setting pop-out
- Improved pop-out reset device
- Transparent cap push-to-reset
• Production release targeted 3Q02
New EMCD Design

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CFM EMCD Failure