CFM56-7 Overall HMU Reliability

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CFM56-7
Overall
HMU
Reliability
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 2
CFM56-7 P07 HMU Removals / MTBUR
0
5
10
15
20
25
30
35
40
45
50
Jan-01
Feb-01
Mar-01
Apr-01
May-01
Jun-01
Jul-01
Aug-01
Sep-01
Oct-01
Nov-01
Dec-01
Removals
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
MTBUR
HMU Removals
6-Month MTBUR
12-Month MTBUR
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 3
Removal Cause Last 12 Months
116
95
46
43 42 40
33
16 16
9 8
0
20
40
60
80
100
120
140
Chafing / Wrap Fault
FMV F/B
HPSOV Switch
Unknown / Misc
Engine Control Light
DMD/FDBK
BSV
Leak
Precautionary
No Start
No Shutdown
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 4
• HMU reliability remains flat
- Current 12 Month MTBUR is 12,000 Hr’s
- Average removals, 32 per month over the last year
• Corrective Actions for top removal causes
- Chaffing/Wrap Fault is leading cause for removal
- Wire bracket Intro production 5/01, SB issued 9/14
- HPSOV Switch Latching on Starts
• Investigations - Refer to separate presentations
- FMV Feedback Fault
- MSV / BSV position faults
- Fault accommodation introduced in EEC S/W version 7.B.N -
June 2002
Reliability Summary
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 5
CFM56-7B HPSOV Indication System
• Background
- HPSOV switch leading cause of HMU removals and D&C’s
- Joint CFMI/Boeing/Honeywell team have studied design alternatives to
increase reliability to acceptable level
- SPST switch eliminates predominant failure mode via run reed deletion
- New HMU P/N (P08) creates one-way engine/aircraft interchangeability
NC
NO
Arm
NC
NO
Arm
Current Double Throw
Proposed Single Throw
Run contact eliminated
Proposed Switch Configuration
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 6
CFM56-7B HPSOV Field Plan
• Qualification Testing Status
- Completed test program that addressed potential field failure modes
- Endurance testing for both run and shutdown modes
- Bounce testing completed at 1.25X engine “g” levels with Boeing P5-2 card
- Completed 4000 cycle endurance test on prototype switch installed on
development engine
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 7
CFM56-7B HPSOV Field Plan
• Boeing Production
- Introduce new P5-2 panel circuit cards line # 1047 (Complete)
- Introduce new SPST HMU (P08) line # 1077 (Complete)
• Field retrofit of P5-2 circuit cards
- 60 cards per week available for field retrofit (2 cards per aircraft)
- P5-2 Circuit Cards available for entire fleet in approximately 10 months
- Boeing logistics focal identified and will work with CFM/HW
- Customers “No Charge” Purchase Orders will be required
• Customer Contacts:
- Bill Swearengin - Boeing
- Francois Boitelet - CFM SA
- Don Thurnquist - CFM Inc
- Bob Chojnacki - Honeywell
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 8
Interim HMU plan until P5-2 cards attain fleet penetration
•Aircraft must be compatible with new SPST switch
- Aircraft must have new P5-2 circuit
- If new card is not available:
- Convert P08 to P07 (CFM SB 73-068; HW SB CHT1 - 73-0015)
- Shop return HMUs to remain P07 until Aug 2002
- Airlines can elect to note on repair PO to upgrade to P08 (SPST)
- HMU switch kits available “Free Of Charge” for airlines that wish to upgrade
proactively
CFM56-7B HPSOV Field Plan
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 9
Interim HMU plan until P5-2 cards attain fleet penetration
• Honeywell will continue to replace current switches at “No Charge”
- 48 hours notice is required
- Can be accomplished on-wing
- P08 to P07 conversion if required (CFM SB 73-068; HW SB CHT1
- 73-0015)
CFM56-7B HPSOV Field Plan
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 10
Retrofit Strategy
• Hardware will be maintained for unscheduled use
- Honeywell will have both switch configurations available
- Boeing will have aircraft cards available at Spares Dist. Center
- Boeing AOG system will support urgent orders
• Spare engines will be delivered with P08 HMUs
– Can be changed to P07 at customer request by Honeywell
• CFM lease pool engines will remain equipped with P07
– Converted later in the program to allow for flexibility
CFM56-7B HPSOV Field Plan
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 11
Summary
• P5-2 circuit card will be FOC to customer
• New switches/installation will be FOC to the customer
• Logistics focal point identified and contact information to be
published
•AOG scenarios addressed
• Your CFM ATPMs and CSMs will be thoroughly engaged with
customer specific field programs
CFM56-7B HPSOV Field Plan
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 12
Service Bulletin Summary
CFM56-7B HPSOV Field Plan
SB Intent Boeing SB CFM SB H/W SB
On-wing sw N/A 73-037R2 CHT1 73-008R2
replacement
On-wing rev K N/A 73-061R1 CHT1 73-011
sw replacement
with wire support
bracket
Rework P5-2 737-28-1179 N/A N/A
233A3202-28-02
Introduce P08 N/A 73-067 CHT1 73-0014
P08 to P07 N/A 73-068 CHT1 73-0015
Conversion
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 13
FMV Related Faults
• FMV faults have become leading cause of D&Cs in -7B fleet
- Fault codes 73-x034y, 73-x035y (x=Channel, y=Engine position)
- Faults result in Engine Control Light indication in cockpit
- Driving 10 HMU removals per month
- No operational events
• Extensive root cause investigation on-going
- Analysis, component, systems rig testing
• Design and manufacturing process changes are being incorporated to
address identified failure modes
• Additional changes for improved reliability being defined, evaluated and
tested
- Design, manufacturing, software logic
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 14
• HMU and resolver analytical efforts
- Tolerance studies, loads, modal, thermal effects including finite
element analysis
• HMU Testing at Burbank
- Run-as-received, electrical checks, inspections (wires, binding,
wobble)
• Resolver Module Testing at Kearfott
- Room temperature electrical tests and thermal cycling (all)
- “Shake & bake” testing (10 units) - no failures observed
- Wire disassembly of unconfirmed units (7) - 2 rubbed rotors observed
FMV Root Cause Investigation - Scope
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 15
• Systems level testing on CFM systems rig
- Focus on unconfirmed units
- Allows monitoring of individual windings and EEC faults
• HMU / Resolver module testing at Honeywell - South Bend
- Cell 8 rig test temperature and FMV cycling - 11 units
- Vibe testing for intermittent opens / shorts - 26 units
- Thermal and moisture tests of resolvers to check for shorts - 13 units
- Load testing for channel disagree faults - 2 units
FMV Root Cause Investigation - Scope
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 16
FMV Root Cause Investigation - Findings
• Fault confirmation rate currently 42%
- 74% resolver, 26% HMU-related
• Fault tree analysis used to identify 70 possible failure contributors
- 65 of these have been investigated
• Design and process improvements incorporated for 11 of 12
failure modes identified to date
- Implemented in new production and field return units following
introducPteirocenntage
42%
58%
74%
26%
Unconfirmed Confirmed Resolver
HMU
CFM56 Operators Conference – May 21 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 17
FMV Root Cause Investigation - Findings
• Majority of resolver failures
related to wiring issues
- Quality and position
adjustment lessor
contributors
• “Rotor winding open” to be
addressed 2Q’02
- Improved strain relief at
termination
- Wire gauge increase from
43 to 42 …currently being
tested
0
2
4
6
8
10
12
14
16
Rotor Winging Open
Lamination Damage/Binding
Stator Termination Failure
Sator Winding Open
Insulation Resistance
Rotor Termination Failure
Resolver Position Adjusted
Wire Chafing
High Eng Play
Bent Connector Pin
Mis-pinned Connector
FMV Extension Wobble
End Play Stator Termination
Rotor Opens in
Winding and Near
Termination
Stator Winding
Open
Low Insulation
Resistance
Resolver Schematic
Resolver Failure Pareto
Corrective Action in Process
Corrective Action In Place
No Corrective Action Defined

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CFM56-7 Starter Reliability

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CFM56-7 Overall HMU Reliability