CFM56 Inlet Gearbox Hardware No 3 Bearing Reliability CFM56-7B Aft Air/Oil Seal

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CFMI Proprietary information
CFM56 Inlet Gearbox Hardware
No 3 Bearing Reliability
CFM56-7B Aft Air/Oil Seal
October, 2004
2
CFMI Proprietary information
CFM56-7B Inlet Gearbox Assembly
No 3 Ball Bearing
Spring Housing No 3 Roller Bearing
Horizontal Bevel Gear
No 3 Forward Air/Oil Seal No 3 Aft Air/Oil Seal
No 3 Bearing Lock Nut
Inlet Gearbox Housing
24 Nuts that hold 3B/3R/Spring
Housing to IGB Housing
This gearbox is used in the CFM56-5A, CFM56-5B,
CFM56-5C, and CFM56-7B engine applications
3
CFMI Proprietary information
CFM56 No. 3 Ball Bearing Reliability
October 2003 thru September 2004
UER's IFSD Hours UER Rate IFSD Rate
CFM56-3 1 1 9.898 0.101 0.101
CFM56-7 2 0 9.250 0.216 0.000
Total 3 1 19.148 0.157 0.052
Note: Rates are
per Million
Engine Flight
Hours
• CFM56-3/-7B Models- Hard Particle Contamination
– CFM56-3 S/B 72-923 recommends 50-75 Hour inspection interval on engines delivered
between April, 1997 and ESN 860-226 until they reach 10,000 Hours
– Extensive IGB Cleanliness Improvements incorporated across all CFM56 Production
• CFM56-7B Programs - Ball Skidding
– Engineering investigation – Bearing offset has impact on skidding
– Engine Testing Complete – Able to reproduce skidding with minimum offset housing
– Design change in place to increase min offset
– Field action to inspect Spring Housing at exposure, re-identify or modify to achieve offset
• CFM56-3/-7B Models - Winsted Non-Tumbled Ball Population (Fleet Highlites Aug 2002)
– Root Cause Identified – No Field Actions recommended
– Corrective Actions implemented at all bearing suppliers
• Residual Stress Specification Implemented 12/00
• Heat Treat and Improved Tumbling Process are now VSE controlled at all vendors
• CFM56-3/-7B Models - MRC Ball Cracking
– Root Cause Identified – Corrective Actions Implemented – No Field Actions recommended
4
CFMI Proprietary information
CFM56-7B No 3 Bearing Reliability
How does the No 3 bearing reliability compare with total fleet?
CFM56-Total Fleet vs. CFM56-7B No 3 Ball Bearing Reliability
12 Month Rolling Average
0.000
0.200
0.400
0.600
0.800
1.000
1.200
Jan-99
Mar-99
May-99
Jul-99
Sep-99
Nov-99
Jan-00
Mar-00
May-00
Jul-00
Sep-00
Nov-00
Jan-01
Mar-01
May-01
Jul-01
Sep-01
Nov-01
Jan-02
Mar-02
May-02
Jul-02
Sep-02
Nov-02
Jan-03
Mar-03
May-03
Jul-03
Sep-03
Nov-03
Jan-04
Mar-04
May-04
Jul-04
Sep-04
Date
Quantity of Events Per Million EFH
CFM56-7B UER Rate
CFM56-7B IFSD Rate
CFM56-Total IFSD Rate
CFM56-Total UER Rate
CFM56-7B Reliability is similar to total CFM56 fleet
Cleanliness and ball process improvements having
impact on total reliability
5
CFMI Proprietary information
CFM56-7 No 3 Bearing Reliability
No 3 Bearing Events since Entry into Service
• 15 Total UER’s / 5 IFSD’s in 32.44 Million Engine Flight Hours
– Cumulative UER/IFSD Rates – 0.462/0.154 events per MEFH
• Investigation Findings
– Hard Particle Contamination – 6 events
– Ball Skidding – 2 Events
– Winsted Ball Residual Stress – 1 Event
– MRC Ball Cracking – 1 Event
– No Root Cause Established – 3 Events
– Under Investigation – 2 Event
Event Date
Eng
Mod
Prod
or O/H ESN
IFSD
UER
Brg TSN Brg CSN Bearing P/N Brg S/N
Engine
Delivery
Date Last MCDI Oil Type
Winsted
Population
MRC
Population
Investigation Findings
9-May-00 7B Prod 874-618 X 3913 1729 1460M52P03 FCAB2990 Mar-99 Normal MCD Insp Mobil Jet 2 Yes No Hard Particle Contamination
27-Aug-01 7B Prod 875-386 X X 7044 3136 1460M52P03 FCAB3906 Nov-98 DMS System- Did not register chip2s3a8t f0ailure. Yes No No Root Cause Established
17-Dec-01 7B Prod 877-205 X X 3262 4984 1665M98P02 MDAHH822 Jan-00 424H/377C 2380 No No Ball Skidding
1-May-02 7B Prod 889-331 X 3136 3098 1460M50P03 FBGE5245 May-01 Normal MCD Insp Aeroshell 560 No No Ball Skidding
28-May-02 7B Prod 877-419 X 5527 3895 1665M98P02 MDAHN045 Jun-00 Normal MCD Insp Mobil Jet 254 No Yes Ball Cracking - MRC
15-Sep-02 7B Prod 876-663 X X 5249 2262 1460M52P03 FCAC1025 Nov-00 280 Hrs/137 Cyc 2380 No No No Root Cause Established
20-Dec-02 7B Prod 888-278 X 4571 2099 1665M98P02 MDAJC188 Apr-01 Normal MCD Insp No No Hard Particle Contamination
12-Mar-03 7B Prod 888-972 X 2688 1927 1665M98P02 MDAKG935 May-02 Normal MCD Insp MJ254 No Yes Under Investigation - BSD
11-Apr-03 7B Prod 888-639 X 3353 1030 1460M52P03 FCAC9834 Oct-01 Normal MCD Insp MJ2 No No Hard Particle Contamination
28-May-03 7B Prod 874-440 X 17154 7200 1460M52P03 FCAB3897 Nov-98 Normal MCD Insp Yes No Residual Stress
4-Jun-03 7B Prod 889-274 X X 7760 2083 1665M98P02 MDAHY887 Mar-01 Chips generated prior to IFSD MJ2 No No Hard Particle Contamination
29-Jul-03 7B Prod 888-301 X 8549 4824 1665M98P02 MDAJC203 Apr-01 500 hours No No Hard Particle Contamination
10-Sep-03 7B Prod 888-321 X X 8621 2476 1665M98P02 MDAJC232 Apr-01 Not reported No No No Root Cause Established
17-Jun-04 7B Prod 876-635 X 10480 3690 1665M98P02 MDAHN623 Oct-00 500 Hours No No Hard Particle Contamination
22-Aug-04 7B Prod 890-691 X 1354 736 1460M52P03 FCAF6023 Jan-04 294 Hours MJ2 No No Under Investigation
6
CFMI Proprietary information
CFM56-7B No 3 Aft Air/Oil Seal Teflon
Problem/Background:
• Epoxy adhesive used to bond the Teflon
seal onto the Air-Oil seal has suffered
cohesive failures on two high time
CFM56-7B engines
• Review of parts at shop visit does not
indicate this is a wide spread issue
• Analysis indicates that this epoxy
adhesive may not have adequate long
term temperature capability
• CFM has a program to qualify a new
higher temperature adhesive for Teflon
– Expect new adhesive availability 4Q04
• Recommendation – replace Teflon at
next shop visit using current adhesive
until new adhesive is available
– CFM requests customers to report any
findings of loose teflon
7
CFMI Proprietary information
Actions / Plan
• Two new adhesives currently in evaluation
– Back-back comparison to current adhesive
• Room temp and elevated temperatures
• Humidity conditioning
• Fluid resistance
– Test completion in Nov-04
• Go Forward Plan
– Document experience at overhaul shops for all CFM models
– Complete testing of new adhesives
– Complete root cause assessment
– Go fwd decision - target 4Q04
8
CFMI Proprietary information
Actions / Plan
• New Adhesive
– Two new 400 F adhesives currently being tested
• EA9673 (Loctite) and FM2550 (Cytec) being compared to baseline
adhesive
• Adhesives have been assessed at room temperature and 350 F in pristine
condition with equal or better performance versus baseline epoxy
• Humidity conditioning (60 days) of other shear test samples in-process.
Will be ready for testing in late October, 04
• Fluid resistance of new adhesives to be assessed based on supplier data
– All testing will be complete in mid November, 04
– GE EMPIS spec drafted to define new adhesive
• Go Forward Plan
– Document experience at overhaul shops for all CFM models
– Complete testing of new adhesive – 4Q04
– Obtain CFMI Tech Review approval
• Target intro by CID – 4Q04
– Intro new adhesive to ESM repairs – 4Q04

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CFM56 Inlet Gearbox Hardware No 3 Bearing Reliability CFM56-7B Aft Air/Oil Seal