波音737-300/400/500 & 737-600/700平台用户环境控制系统区域技术协调会议
PSPM -Larry Johnson CSE - John Newman April 2004
ACM Reliability (Dec. 2003) 717-700 12-Month MTBUR = 32,263 hrs 717-800 12-Month MTBUR = 42,475 hrs 100% Authorized Repair Centers Reporting
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-1 HONEYWELL CONFIDENTIAL
Page 1
Issues
. ACM Removal Drivers
–
Bearing wear- contamination
–
Turbine journal bearing
–
Fan Blade Fatigue
–
Bearing binding - oil contamination
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-2 HONEYWELL CONFIDENTIAL
Page 2
Bearing Wear Due to Particulate Contamination Is Leading Cause of
Removal Fleet Wide, but Normally Occurs at High Flight Hours
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-3 HONEYWELL CONFIDENTIAL
Page 3
737NG ACM FINDINGS -ALL OPERATORS
Bearing Wear/Contamination
Issue
. Erosion of bearing surfaces resulting in premature ACMremovals (seized)
Root Cause
. Particles of material from an external source are beingingested by the ACM
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-4 HONEYWELL CONFIDENTIAL
Page 4
Status
.
This failure mode normally occurs at high time.
.
Low-time failures are experienced by a small numberof airlines
– This problem has been reported by operators in areas thathave significant contaminants such as sand in the air
Resolution
. Under investigation
Bearing Wear Due to Particulate Contamination Is Leading Cause of
Removal Fleet Wide, but Normally Occurs at High Flight Hours
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-5 HONEYWELL CONFIDENTIAL
Page 5
737NG ACM FINDINGS -ALL OPERATORS
Turbine Journal Bearing
Issue
. ACM failure due to turbine journal bearing seizing
Root Cause
. This failure mode may occur if there is a failure in therefrigeration unit low limit temperature control on the -700aircraft. This will allow the turbine to accumulate ice, leading toice shedding and an unbalanced condition
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-6 HONEYWELL CONFIDENTIAL
Page 6
737NG ACM FINDINGS -ALL OPERATORS
Turbine Journal Bearing
Root Cause (Cont)
. This failure mode may occur if the water extraction system doesnot function properly and water is permitted to enter the coolingturbine on the -800 aircraft. This leads to icing of the turbine andsimilar results as in the -700 aircraft
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-7 HONEYWELL CONFIDENTIAL
Page 7
Resolution
.
Proper fault isolation is very important in preventing repeatfailures. Identification of the cause of the icing condition andcorrecting the problem will minimize the problems. Check the pack temperature control system
.
In the -800/900 aircraft the water extraction system must bechecked to ensure the water is being removed and not carried into the turbine, where ice could form on the turbine blades, resulting in an unbalance turbine wheel. Check the water drainlines for blockage
Check the Low Limit Control and the Water Extraction System
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-8 HONEYWELL CONFIDENTIAL
Page 8
737NG ACM FINDINGS -ALL OPERATORS
Issue
. Fan blade separation
Root Cause
. Fan fatigue due to repeated stress on the bladescausing separation
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-9 HONEYWELL CONFIDENTIAL
Page 9
Status
.
An improved fan material was introduced in the -2 ACM.All units failing within the warranty were approved forwarranty and the ACM was upgraded to the -2configuration. All units received for repair were upgradedto the -2 at no additional cost.
.
This failure mode occurs primarily in the -800 aircraft buthas been minimized by the introduction of the improvedfan material.
Resolution
. The -2 ACM has minimized this failure mode
Introduction of the -2 Has Reduced These Occurrences
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-10 HONEYWELL CONFIDENTIAL
Page 10
737NG ACM FINDINGS -ALL OPERATORS
Issue
. ACM failing to start when system is turned on
Root Cause
. Ingestion of oily contaminants may cause increase in breakawaytorque, leading to ACM failing to start
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-11 HONEYWELL CONFIDENTIAL
Page 11
Status
. This failure mode has occurred on few aircraft.
Resolution
.
This condition has been minimized through theintroduction of a new bearing coating.
.
Periodic off wing cleaning of the heat exchangers will alsominimize this failure mode
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-12 HONEYWELL CONFIDENTIAL
Page 12
Logistics
.
Production switched to the new bearing configuration inAugust 2002
.
All ACMs sold since then have the new bearings
.
ACMs repaired since January 2003 have the bearings withthe new coating
Check the Bleed Air Circuit and Correct the Condition at the
Contamination Source
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-13 HONEYWELL CONFIDENTIAL
Page 13
Summary
.
Bearing wear due to particulate contamination is theleading cause of ACM removals
.
Turbine Journal Bearing failure normally is due to icing ofthe turbine
.
Fan Failure have been minimized by the introduction ofthe -2 ACM
.
Introduction of the new bearing coating has been verysuccessful in reducing the problem with binding due tocontamination
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-14 HONEYWELL CONFIDENTIAL
Page 14
Delaminating of the Plenum Due to Resin Loss
Plenum
Bleed Air Inlet
Heat Exchanger
Cooling Air Inlet
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-15 HONEYWELL CONFIDENTIAL
Page 15
Issue
. Delaminating of the plenum due to resin loss
Root Cause
. Analysis is on going (see status)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-16 HONEYWELL CONFIDENTIAL
Page 16
Status
Honeywell is:
.
Conducting temperature test along with an operator to determinethe temperatures to which the plenum is being subjected.
.
Conducting temperature tests on coupons of the plenum materialto determine the amount of resin loss at 400, 425 and 450°F
.
Also conducting temperature test on coupons of an alternatematerial being considered for the plenum.
.
Investigating approaches to minimize the damage done to theplenum during maintenance. (See next slide)
.
Investigating alternate material for HX Plenum gasket.(See next slide)
The Plenum is not repairable beyond what has been provided inthe Component Maintenance Manual. No permanent Repair is available for the plenu
m.
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-17 HONEYWELL CONFIDENTIAL
Page 17
Plenum Flange Sleeve Under Consideration
. To be placed over the plenum flange to protect and provide support
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-18 HONEYWELL CONFIDENTIAL
Page 18
12345
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-19 HONEYWELL CONFIDENTIAL
Page 19
Platform: B737-400/800/900
Matt McClure Customer Service Engineer FSCM/Cage Code 59364, ESA Tempe AZ 6 April, 2004
Trace Data 12 months ending June 30, 2003
B737-400 Fleet MTBUR = 12,405 hrs Fleet MLBUR = 8,733 cycles Percent Reporting = 37%
B737-800/900 Fleet MTBUR = 19,639 hrs Fleet MLBUR = 9,709 cycles Percent Reporting = 40%
Honeywell Internal Information ATLAS SR#: 1-13245101 CSB #: 9-00024
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-20 HONEYWELL CONFIDENTIAL
Page 20
Issue
.
Valve is binding during operation Root Cause
.
Motor bearings are not sealed on failed hardware
– Grease migrates out of bearing and contaminants migrate intobearing causing bearing to seize
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-21 HONEYWELL CONFIDENTIAL
Page 21
The Seal in the New Bearing Will Keep Contaminates Out
and Grease in
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-22 HONEYWELL CONFIDENTIAL
Page 22
Status
.
New motor bearing, P/N 533264 Rev “V” and subsequent has beenavailable since October 2003
.
Production valves are receiving the new bearings
.
Repaired valves will receive the new bearings on attrition during anormal shop visit when motor bearings are replaced
.
There is not an SB to incorporate the new bearings
– There is no re-identification of the valve or actuator
On Going Plan
.
An actuator cycle test is in process to quantify the benefits of the newbearing and analyze Actuator “coasting”
–
Some additional testing has been added, which now extends the completiondate from the previously communicated date of end of April 2004 to end ofMay 2004
–
Re-identification based on the bearing change will be evaluated at thecompletion of the Actuator cycle test
.
The go-forward plan will be finalized following a review of the actuatorcycle test results
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-23 HONEYWELL CONFIDENTIAL
Page 23
Platform: Boeing 737-600/700/800, 131-9B APU
Cornelis deKoe Customer Service Engineer CAGE Code: 64547 Tucson, AZ 11 March 2004
.
Reliability Summary
.
TRACE Data Through September 2003
–
Fleet MTBUR 11,136 hrs
–
Fleet Percent Reporting = 39%
.
Calculated Starter-Gen and diode reliabilityas of 09/03 (based on shop data):
–
MTBF: 15,549 hr
–
MTBUR: 10,345 hrs
–
Diode MTBF: 1,270,000 hr (was 880,178 hr)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-24 HONEYWELL CONFIDENTIAL
Page 24
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-25 HONEYWELL CONFIDENTIAL
Page 25
Summary of Reliability Issues
.
#1 - High No Fault Found (NFF) rate
–
Significant reduction in NFF rate observed during 2003
–
42% of current NFF are returned for ‘Overhaul or Test Only’
.
#2 - Main Rotor lead failures
– Results in no electrical output (generator offline or APU no start)
. Possible Maintenance Messages:
.
49-41245 (under-voltage)
.
49-41012 (no rotation)
.
49-41010 (no acceleration)
.
#3 - Main Rotor crossover failures
– Results in no electrical output (generator offline or APU no start)
. Possible Maintenance Messages:
.
49-41245 (under-voltage)
.
49-41012 (no rotation)
.
49-41010 (no acceleration)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-26 HONEYWELL CONFIDENTIAL
Page 26
Summary of Reliability Issues (Cont)
.
#4 - Diode failures
–
Shorted diode causes high field current ripple, detected by SCU
.
Possible Maintenance message:
. 49-41244 (shorted rotating diode fault)
.
Blue maintenance light illuminates in cockpit
–
Open Diode
.
Limits generator Loading
.
Slower APU Starts
.
#5 - Main Rotor Shorts (MRS)
– Results in low output from generator
. Possible Maintenance message:
. 49-41245 (under-voltage)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-27 HONEYWELL CONFIDENTIAL
Page 27
Root Cause: High NFF Rate
.
Approximately 45% of the NFF returns in 2002result from a known issue associated with P/N 1152466-250 series 2 Starter Converter Unit (SCU)
–
Transient electrical noise sensitivity in SCU causes falseShorted Rotating Diode (SRD) indication
.
Illuminates blue APU MAINT light in cockpit
.
APU maintenance message 49-41244
–
Correct troubleshooting procedures not being followed
.
Honeywell In Service Summary Report (ISSR) update, dated 26July ‘01
.
Boeing Fault Isolation Manual (FIM) 49-40, task 806, dated 7October ‘02
.
Other causes of NFF removals (remaining 55%) arecurrently being reviewed
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-28 HONEYWELL CONFIDENTIAL
Page 28
Resolution: High NFF Rate
.
Short term
– Troubleshooting per Honeywell ISSR and Boeing FIM
.
Longer term
– SCU design change Status
.
Short term
–
Honeywell ISSR update released 26 July 2001
–
Boeing FIM 49-40, task 806 revised 7 October 2002
.
Longer term
– P/N 1152466-250 series 3 introduced June 2002
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-29 HONEYWELL CONFIDENTIAL
Page 29
Benefits: Resolution for High NFF Rate
.
Minimizes false SRD generator returns Logistics
.
P/N 1152466-250 series 2 SCUs upgraded to series 3
–
Per SB 1152466-49-13
–
Free of charge modification
–
Modified on first return to Honeywell
–
Approximately 75% (285 units) still to be modified
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-30 HONEYWELL CONFIDENTIAL
Page 30
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-31 HONEYWELL CONFIDENTIAL
Page 31
Resolution: Rotor Lead Failures
.
A - Process improvement
– Length of unrestrained rotor lead minimized
.
B - Design improvement
– Rotor leads tied to oil deflector
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-32 HONEYWELL CONFIDENTIAL
Page 32
Status: Resolution for Rotor Lead Failures
.
A - Process improvement
– Implemented February 2002
.
New production implementation at S/Ns greater than XXX-A01039
.
Implemented for all rewound rotors
.
B - Design improvement
– Drawing change released Feb 2003
. New production implementation S/N: 83-A1371
Benefits
. Increased support of the main rotor leads, minimizingstresses and movement during operation
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-33 HONEYWELL CONFIDENTIAL
Page 33
Logistics: Resolution for Rotor Lead Failures
.
Improvements will be carried out on attrition
– Rewind of failed rotor
.
No recall is necessary
.
Disassembled generators will be inspected fordamaged leads or sleeving
–
Implemented March 2003
–
Rotors that fail inspection will be rewound or replaced
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-34 HONEYWELL CONFIDENTIAL
Page 34
Root Cause: Rotor Crossover Lead Failures
. Insufficient lead strength on some units due toproduction variability
– Results in failure in operation under CF and vibration loading
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-35 HONEYWELL CONFIDENTIAL
Page 35
Resolution: Rotor Crossover Lead Failures
. Design/process improvement
–
Better definition of lead routing in assembly
–
Increased strength of lead
Add Insulating Sleeve Around Brazed Joint, Tie It to Windings, and Coat Joint With Heresite to Increase Strength
Main Rotor
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-36 HONEYWELL CONFIDENTIAL
Page 36
Resolution: Rotor Crossover Lead Failures
. Design improvement (cont)
– Assembly process updated
Status Secure Connection With Lacing Cord asShown Prior to Dip and Bake
. Completed
– SN 83-A1371
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-37 HONEYWELL CONFIDENTIAL
Page 37
Root Cause: Diode Failures
. Cause of decreasing reliability currently underinvestigation by Engineering
– Centrifugal loading of diode terminal by terminal leads may bea contributing factor
Blue Diode White Diode (3 Per Rotor) (3 Per Rotor)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-38 HONEYWELL CONFIDENTIAL
Page 38
Resolution: Diode Failures
. Design improvement
– Tie diode leads to exciter bobbin
.
Increases lead support under centrifugal loading
.
Stabilizes lead position
Position and Tie Six Leads to Resistor Bobbin Using Lacing Cord, Then Coat With Epoxy
Further Corrective Actions to Be Determined Based on Failure
Analysis Results
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-39 HONEYWELL CONFIDENTIAL
Page 39
Status: Corrective Action for Diode Failures
.
Drawing change released Feb 2003 to tie diode leadsto bobbin
– New production implementation S/N: 83-A1371
.
Engineering Investigation on Hold
–
Reliability of Diodes has tripled over last 12 Months
–
MTBF increased from 431,000 hours (11-2002) to 1,270,642Hours (11-2003)
–
Two failed diodes sent to manufacturer for analysis
.
Detailed analysis will continue to be carried out onfuture failures
.
May be more than one failure mode
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-40 HONEYWELL CONFIDENTIAL
Page 40
Benefits: Corrective Action for Diode Failures
. Improved support of diode leads reduces centrifugalforce on diode terminal
Logistics
. R&O units disassembled for any reason will havediode leads tied to exciter bobbin
– Implemented March 2003
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-41 HONEYWELL CONFIDENTIAL
Page 41
Root Cause: Main Rotor Shorts
.
Damaged insulation during operation or assembly Resolution
.
Design improvement
Added Kapton Insulation Tape Between Each Rotor Winding Stack and the Rotor Core, in Addition to Nomex Insulation
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-42 HONEYWELL CONFIDENTIAL
Page 42
Status: Resolution for Main Rotor Shorts
. Drawing change released Feb 2003
– New production implementation S/N: 83-A1371
Benefits
. Reduced risk of rotor shorts
Logistics
.
Improvement will be carried out on attrition for fieldunits
– Rewind of failed rotor
.
No recall is necessary
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-43 HONEYWELL CONFIDENTIAL
Page 43
Platform: B737-600/700/800/900 CFM56-7
Stephan Cronenberg Sr. Customer Service Engineer FSCM/Cage Code 59364, ESA Tempe AZ 30 January 2004
Trace Data From Sept 2003 Fleet MTBUR = 8461 hrs Percent Reporting = 31%
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-44 HONEYWELL CONFIDENTIAL
Page 44
Issue
.
3215618-3 Nose Cowl Anti- Ice Valve has a high removal rate
.
Valves are often removed due to Amber warning light
–
This is an overpressure indication
–
Faults most predominate at high engine power settings
–
Some PIREPs indicate that light goes out if power setting reduced
.
Operators are reporting MTBF as low as 4500 hours
.
Qualification test failure during bursts testing caused actuatorcover to crack
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-45 HONEYWELL CONFIDENTIAL
Page 45
Shop Findings
.
The reference regulator is noted to be stuck open or contaminated orheavily worn on returned units
.
These conditions prevent the regulator from controlling down streampressure leading to an overpressure indication
.
Findings confirm the removal reasons and PIREPs regarding light on athigh power settings
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-46 HONEYWELL CONFIDENTIAL
Page 46
Root Cause
.
Buzzing of the regulator, or instability, has been identified as the rootcause of the reference regulator wear
.
Buzzing induced movement of the poppet lead to excessive wear of thepoppet and guide and the inability to regulate
.
Factors that contribute to instability and wear:
–
Clearance between poppet stem and bore of seat
–
Natural frequency of the spring and spring mass
–
Upstream and downstream volume
–
Aircraft vibration and amplification through duct and valve
–
Mass of the diaphragm assembly
–
Materials used in poppet, seat and guide bore
.
Qualification test failure during bursts testing caused actuator coverto crack
–
Slight change in required pressures for proof and burst qualification andcertification tests resulted in failure during test of dash 4 valve
–
Condition never found in actual service on aircraft
–
Qualification / certification requirement
–
No known field failures
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-47 HONEYWELL CONFIDENTIAL
Page 47
Root Cause
Location of Location of
Shuttle Valve Reference
Housing Regulator
Existing Reference Regulator Assembly
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-48 HONEYWELL CONFIDENTIAL
Page 48
Existing Design
Heavy Diaphragm
Guide (Deleted on
New Design)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-49 HONEYWELL CONFIDENTIAL
Page 49
Solution
. Add relief valve to shuttle housing Existing Shuttle
to less than 220 psig Valve Orifice
– Limits pressure in closing chamberRelief
Valve
Added
– Prevents higher pressures from
Added
acting on closing chamber during
proof and burst tests
– Will not vent in normal service only
during production ATP and
certification tests at Honeywell
New Shuttle Housing Existing Shuttle Housing With Relief Valve
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-50 HONEYWELL CONFIDENTIAL
Page 50
Status
.
Due to Qualification failures in Jan 2003 original SBrelease was delayed
–
Failures not related to new reference regulator
–
Bursts pressure test failure
.
Post mod configuration will be 3215618-4, presentlydash 3
.
Service bulletin 3215618-30-1071 released July 2003
– SB is no charge for limited time
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-51 HONEYWELL CONFIDENTIAL
Page 51
Benefits
.
Improved reference regulator
–
Will eliminate the reference regulator induced amber lightremovals
–
Other B737-300/400/500 & B737-600/700/800 valves with thisregulator demonstrate good reliability
–
B737 pilot valves have a 10.5% replacement rate on thereference regulators compared to 60% on the anti-ice valve
.
New relief valve prevents proof and burst test issues
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-52 HONEYWELL CONFIDENTIAL
Page 52
Platform: B737-300, -400, -500
Stephan Cronenberg Sr. Customer Service Engineer FSCM/Cage Code 59364, ESA Tempe AZ 3 October 2003
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-53 HONEYWELL CONFIDENTIAL
Page 53
Current Issue
.
Operators are experiencing a lower than desired reliability onthis valve
.
The fleet MTBUR is approximately 7200 hours
Status
. Review of Honeywell shop findings database suggests that thesingle largest cause of valves that fail incoming test is the reference regulator
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-54 HONEYWELL CONFIDENTIAL
Page 54
Existing Design
Heavy Diaphragm
Guide (Deleted on
New Design)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-55 HONEYWELL CONFIDENTIAL
Page 55
Solution (Cont)
.
Honeywell R&O shop inAnniston has found switches operating intermittently due toexcessive torque on mounting screws
.
CMM specifies proper torque forswitch screws (1.0 - 1.5 in/lbs)
.
R&O shops need to follow CMMinstructions
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-56 HONEYWELL CONFIDENTIAL
Page 56
Status
.
Reference regulator improvement being developed on 3215618(B737 NG NCAIV)
.
The 3290662 and 3215618 use same reference regulator
.
Service bulletin release estimated mid to late 2004
– Actual dates dependant on Boeing approval of various documents
Benefits
. Improved reference regulator
–
Will eliminate the reference regulator induced amber light removals
–
Other B737-300/400/500 & B737-600/700/800 valves with this
regulator demonstrate good reliability
–
B737 pilot valves have a 10.5 % replacement rate on the referenceregulators compared to 60% on the anti-ice valve
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-57 HONEYWELL CONFIDENTIAL
Page 57
Platform: CFM56-7, Boeing 737-600/700/800/900
Brian Albing Sr. Customer Service Engineer FSCM / CAGE Code: 59364 (Tempe) 19 January 2004
Trace Data From Sept 2003
737 CL Fleet MTBUR = 11740 hrs
Percent Reporting = 31%
737 NG Fleet MTBUR = 12508 hrs Percent Reporting = 31%
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-58 HONEYWELL CONFIDENTIAL
Page 58
Issue
.
Bleed Air Regulator on B737NG is exhibitingdecreasing reliability
.
Relief Valve and Reference Regulator wear is noted atshop visit
.
Control Pressure is reduced if wear becomes significant and component must be removed formaintenance
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-59 HONEYWELL CONFIDENTIAL
Page 59
Root Cause
. Vibration levels appear to be causing the increased wear notedon this component
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-60 HONEYWELL CONFIDENTIAL
Page 60
Status
.
A team has been formed to investigate this problem
.
The team members have been drawn from Boeing andHoneywell
.
Hardware from Anniston is being used to study theeffects of the regulator and relief valve wear
.
Team plans to identify the most significant vibrationfrequencies and vibration axes
.
Status report early Q2 2004
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-61 HONEYWELL CONFIDENTIAL
Page 61
Platform: CFM56-7, Boeing 737-600/700/800/900
Brian Albing Sr. Customer Service Engineer FSCM / CAGE Code: 59364 (Tempe) 19 January 2004
Trace Data From Sept 2003
737 CL Fleet MTBUR = 17478 hrs
Percent Reporting = 31%
737 NG Fleet MTBUR = 19220 hrs Percent Reporting = 31%
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-62 HONEYWELL CONFIDENTIAL
Page 62
Issue
.
High Stage Regulator exhibits badly worn and deterioratedreverse flow diaphragms
.
Relief valves often noted as worn and leaking
Overpressure Shutoff
Relief Valve
Reverse Flow
Diaphragm
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-63 HONEYWELL CONFIDENTIAL
Page 63
Root Cause
.
High stage air leaking past overpressure shutoffshortens life of reverse flow diaphragm
.
Once diaphragm fails the control pressure is very lowand unit must be removed
Status
.
This problem has been sent to Honeywell CustomerSatisfaction Board for review and ranking
.
CSB to complete initial analysis and priority
.
Status report early Q2 2004
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-64 HONEYWELL CONFIDENTIAL
Page 64
Platform: B747/767/777
PSPM -Larry Johnson CSE - John Newman April 2004
Existing Design: P/N 606802 New Design: P/N 645172
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-65 HONEYWELL CONFIDENTIAL
Page 65
.
Issue (With 1st Generation Blower 606802)
.
Cost of ownership
Root Cause
.
Bearing life
.
Requires operators to maintain spare parts/filters
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-66 HONEYWELL CONFIDENTIAL
Page 66
Resolution
. Honeywell is introducing a new 2nd generation vacuum blowerfor all Boeing platforms and will be phasing out the existing1st generation blower
– 1st generation blowers in the field will continue to be supported withR&O services and spare parts
Features of New Blower
.
Drop in replacement
.
Doesn’t violate any of the current Boeing blower specs
.
Significant improvements in aerodynamics and acoustics
.
Simpler design eliminates high maintenance parts
.
Substantial reduction in cost of ownership
.
Production cut-in begins 3rd Qtr, 2003; available to field4th Qtr, 2003
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-67 HONEYWELL CONFIDENTIAL
Page 67
Availability
.
Production cut-in begins 3rd Qtr, 2003 on all Boeingproduction platforms
.
End-units available for aftermarket sales beginning4th Qtr, 2003
.
Existing blower, PN 606802-2, will continue to besupported with maintenance and spares
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-68 HONEYWELL CONFIDENTIAL
Page 68
Paul R. Aurand Customer Service Engineer FSCM / CAGE Code: 06848, South Bend 19 March 2004
CFM56-7 HMU MTBUR
MTBUR
16000
14000
12000
10000
.
MTBUR approaching 14,200 hours
.
Demand / Feedback #1 removal cause
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-69 HONEYWELL CONFIDENTIAL
Page 69
Fault Codes Needed for Unknown/Miscellaneous and Engine
Control Light Removals
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-70 HONEYWELL CONFIDENTIAL
Page 70
Issues
#1 - Demand / Feedback Faults (TBV EHSV) – Increasing #2 - Fuel Metering Valve (FMV) Feedback Faults (Resolvers)
– Decreasing #3 - Precautionary - Overhauls, etc. (Not Counted) #4 - Wire Chafing Resulting in Wrap Faults – Same #5 -Fuel Leaks – Same #6 -High Pressure Shutoff Valve (HPSOV) Switch – Same #7 - Engine Control Light and Unknown/Misc – Decreasing #8 - Contamination - Externally Induced, Under Investigation
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-71 HONEYWELL CONFIDENTIAL
Page 71
Issue #1 – Demand/Feedback (TBV) Position Disagreement Faults
.
Engine Control Light / Primary cause is TBV EHSVDemand/Feedback Disagree Fault Code
.
Average Monthly Removals for this DMD / FDBK Issue: 12
– Removed HMU summary:
.
Engine Control Light
.
TBV position signal Fault Code 73-x058n – 125 of 141 Returns
.
47% Confirmation Rate – Other Potential Causes on Engine?
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-72 HONEYWELL CONFIDENTIAL
Page 72
Cause – TBV Position Disagreement Fault
.
Engine Control Light/TBV EHSV demand/feedback disagree
.
TBV EHSV used as 2-position device
–
Vibration-induced fretting wear of armature due to contact with stop screw
.
“Dimple” worn into armature
.
Causes reduction in armature-to-pole piece air gap, results in magnetic latching force exceeding available pull-in force
–
Results in EHSV “latching” in energized or de-energized positions
.
Wear is not time-dependent
.
Variation in engine environment a factor in EHSV life
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-73 HONEYWELL CONFIDENTIAL
Page 73
Resolution – TBV Position Disagreement Fault
. Addition of feedback wire eliminates armature contact
–
Detailed design review with GE/CFM engineering
–
Low risk modification based on similarity with other EHSV’s
Area of Dimpling Wear:
Fretting Between Armature
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-74 HONEYWELL CONFIDENTIAL
Page 74
Status – TBV Position Disagreement Fault
. Resolution/Application:
–
100% TBV EHSV replacement with new EHSV when removedfor cause
.
Provided regardless of confirmation since May 2002
.
Provided FOC on units removed/verified for FMV faults –Ref. SIL No. 8
–
Modified TBV feedback design
.
TBV EHSV available in CFMI S/B 73-0093/Honeywell CHT1-73-0020
.
SIL No. 8 discount to encourage proactive modification to P09
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-75 HONEYWELL CONFIDENTIAL
Page 75
Issue #2 - Fuel Metering Valve (FMV) Feedback Faults (Resolvers)
.
Engine Control Light/FMV signal out of range or FMV channeldisagreement Fault Codes
.
Average Monthly Removals for this Issue: 11
– Removed HMU summary:
.
FMV position signal Fault Codes 73-x034n & 73-x035n
.
Engine Control Light
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-76 HONEYWELL CONFIDENTIAL
Page 76
Cause – Fuel Metering Valve (FMV) Feedback Faults (Resolvers)
. Investigation:
–
Resolver modules subjected to extensive thermal cycling, vibrationand destructive disassembly
–
60% Unconfirmed with testing at the HMU level
–
40% Confirmed
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-77 HONEYWELL CONFIDENTIAL
Page 77
Status – Fuel Metering Valve (FMV) Feedback Faults
. Confirmed Unit Analysis:
–
Data-Driven Fault tree analysis complete
.
Identified 70 possible contributors
.
All known HMU causes have been addressed
–
13 identified modes contributed to the confirmed FMV faults
. Modification incorporated for all of the 13 identified modes
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-78 HONEYWELL CONFIDENTIAL
Page 78
Status – Fuel Metering Valve (FMV) Feedback Faults (Cont)
. Unconfirmed Unit Investigation:
–
Analysis and testing has eliminated resolvers as contributor to theunconfirmed population
–
FMV linkage investigation concluded:
. 6 Separate product modifications incorporated since May 2001
–
Resolver investigation concluded:
. Modifications to extend life - some removals still expected
–
No New HMU-Related Failure Modes Identified Since Oct. 01
. All HMU Causes Addressed
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-79 HONEYWELL CONFIDENTIAL
Page 79
Status – Fuel Metering Valve (FMV) Feedback Faults (Cont)
.
Resolution/Application:
– 100% FMV resolver replacement with new resolver when removed forcause (SB CHT1-73-0021 )
.
Provided regardless of confirmation since May 2001
.
Provided FOC on units removed / verified for FMV faults, Ref. SIL No 8
.
Two Phases:
– Modified FMV linkage and FMV resolver replacement
.
FMV linkage available in CFMI S/B 73-0075 / Honeywell CHT1-73-0016
.
FMV resolver available in CFMI S/B 73-0094 / Honeywell CHT1-73-0021
.
SIL No 8 discount to encourage proactive modification to P09
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-80 HONEYWELL CONFIDENTIAL
Page 80
Issue # 3 Precautionary
.
Overhauls, Check and Test, Re-Certification, etc.
.
Average Monthly Removals for This Issue: 5
– Removed HMU summary:
. No Fault Code Available
.
Not Counted for MTBUR
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-81 HONEYWELL CONFIDENTIAL
Page 81
Issue # 4 – Wire Chafing Resulting in Wrap Faults
.
Engine Control Light / Fault Codes
.
Average Monthly Removals for this Issue: 4
– Removed HMU summary
.
Various Wrap Fault Codes
.
Engine Control Light
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-82 HONEYWELL CONFIDENTIAL
Page 82
Cause – Wire Chafing Resulting in Wrap Faults
.
Wrap Faults Forces EEC Channel Swaps
.
Wire insulation is being worn away in areas where wires contactedges in HMU cavity
–
Excessive wire lead lengths in HMU cavity
–
Sub-optimum method of wire bundling
Pre SB CHT1-73-0010
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-83 HONEYWELL CONFIDENTIAL
Page 83
Resolution – Wire Chafing Resulting in Wrap Faults
. Short Term
–
Modified Deburr and Relocated Wire Ties
.
S/N BECW1509 and up – modified deburr and relocated wire ties
.
S/N BECW1736 and up – modified manufacturing process toeliminate sharp edge
–
Inspected wires during HPSOV SB switch replacements
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-84 HONEYWELL CONFIDENTIAL
Page 84
Status – Wire Chafing Resulting in Wrap Faults
. Long Term
–
Additional bracket with tie-downs introduced at HoneywellOEM May 2001 (BECW2346 & up), Service BulletinCHT1-73-0010 released September 2001
–
Modified wire length and wire bracket tie-down routing
–
In-service HMU's “no charge” at next shop visit
New Bracket
HMU With Tie-
down Bracket
Wire Tiedowns
Post SB CHT1-73-0010
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-85 HONEYWELL CONFIDENTIAL
Page 85
Issue # 5 – Fuel Leaks
.
External Fuel Leakage Exhibited with Engine Shut Down
– Removed HMU summary:
. No Fault Code Available
.
Average Monthly Removals for this Issue: 4
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-86 HONEYWELL CONFIDENTIAL
Page 86
Cause – Fuel Leaks
.
Fluorosilicone Fuel-Air O-rings
.
Compression set with age (temperature/cycles)
.
Observed on high-time HMUs during Analytical ConditionInspections (ACI)
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-87 HONEYWELL CONFIDENTIAL
Page 87
Status – Fuel Leaks
.
Short Term
–
Reviewed all fuel-air O-ring design standards
–
Initiated low pressure leak check on HMU removed for externalleakage
.
Long Term
– Investigate Fluorocarbon O-rings for OEM/Aftermarket application
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-88 HONEYWELL CONFIDENTIAL
Page 88
Resolution – Fuel Leaks
.
Short Term
–
Replace Max Stop Adjustment Screw per SB CHT1-73-0025
–
Low pressure leak check SB CHT1-73-0026 for HMU removed forleakage
.
Long Term
– Engineering testing of Fluorocarbon O-rings - completion 2ndQuarter 2004
.
Improve compression-set performance
.
Reduce lower-time HMU removals for external leakage
.
Increase time in service
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-89 HONEYWELL CONFIDENTIAL
Page 89
Issue # 6 Pressure Shut-Off Valve (HPSOV) Switch
.
Flight deck P5-2 Panel indications of “ENG VLV CLSD” lightstaying bright after engine shutdown
.
No Fault Code set
.
Average Monthly Removals for this Issue: 3
– Removed HMU summary:
. Engine Valved Closed Light
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-90 HONEYWELL CONFIDENTIAL
Page 90
Cause – High Pressure Shut-Off Valve (HPSOV) Switch
.
Mechanical Interaction of Reed Mating Surface Causing SwitchContacts to “Stick”
.
Severe Vibration Environment (Fuel Pump) at Switch
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-91 HONEYWELL CONFIDENTIAL
Page 91
Resolution – High Pressure Shut-Off Valve (HPSOV) Switch (Cont)
.
Short Term
–
Continue On-Wing HPSOV Switch Replacements by Honeywell FSEs/Trained Airline Maintenance Personnel
–
Service Bulletins CHT1-73-0014/CHT1-73-0015 and correspondingCFMI SB for SPST switch and Boeing Service Bulletins for P5-2Panel released February 2002
.
Long Term
–
Circuit card and switch availability sufficient to complete field
incorporation in 2003
–
Additional on-wing capability available after modification
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-92 HONEYWELL CONFIDENTIAL
Page 92
Status – High Pressure Shut-Off Valve (HPSOV) Switch
.
Short Term
– On-Wing HPSOV Switch Replacements by Honeywell FSE's andTrained Airlines Almost Completed
. Service Bulletins will allow field conversion of the HMU to either configuration
.
Long Term
–
FSEs trained to accomplish Switch replacements
–
Transition HPSOV Switch replacements to trained Airline
Maintenance Personnel
–
Maintenance / troubleshooting very important
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-93 HONEYWELL CONFIDENTIAL
Page 93
Issue # 7 Engine Control Light and Unknown/Misc
.
Various Causes
.
Average Monthly Removals for These Issues: 4
– Removed HMU summary:
.
Engine Control Light
.
No Fault Code Available
.
Very Important to Obtain Fault Code
–
Assist in HMU Troubleshooting/Repair
–
Better Definition of Removals
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-94 HONEYWELL CONFIDENTIAL
Page 94
Issue # 8 Contamination
.
Externally Induced
.
Average Monthly Removals for These Issues: 2
– Removed HMU summary:
. No Fault Code Available
.
Under Investigation
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-95 HONEYWELL CONFIDENTIAL
Page 95
PN 442317 (1853M56P09)
.
OEM introduction 04/03
.
Field introduction 05/03 Service Bulletins CFM56-7B S/B 73-0081/CHT1-73-0024
.
Addresses all known, confirmed HMU-related removals
–
Only 40% of the total confirmed FMV removals
–
SIL No 8 discount to encourage proactive modification to P09
.
Revised February 27, 2004
.
Prices extended to end of December 2005
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-96 HONEYWELL CONFIDENTIAL
Page 96
Platform: B737-600/-700/-800/-900
Bob Gildenstern Sr. Customer Service Engineer FSCM/Cage Code 59364, ESA Tempe AZ
Trace Data through Sept. 2003 Fleet MTBUR = 13,359 hrs Percent Reporting = 30%
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-97 HONEYWELL CONFIDENTIAL
Page 97
Issues
.
Issue #1
– Oil leak number one field removal cause
.
Issue #2
– Turbine Bearing Failure
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-98 HONEYWELL CONFIDENTIAL
Page 98
Issue # 1
. Oil leak number one field removal cause, > 70%
. Typical Symptoms
.
White smoke during engine starts
.
Oil dripping from starter exhaust screen
Root Cause
. Primary Cause: Turbine seal carbon ring hanging up in seal case
– O-ring at carbon after aging develops increased friction that seal pre-load springs cannot overcome causing gap between carbon and sealrotor resulting in oil leak.
Resolution
. Incorporate new turbine seal o-ring material that generates lessfriction
– New turbine seal creates starter P/N 3505945-9
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-99 HONEYWELL CONFIDENTIAL
Page 99
Exhaust Screen
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-100 HONEYWELL CONFIDENTIAL
Page 100
Issue # 1
Status
.
First production 3505945-9, series 1, in June 2002 – -9 to contain new turbine seal
.
SB 80-1756 released June 2002
– Current -7 and -8 starters to be upgraded to -9 chg #1
Benefit
. Eliminate starter oil leakage due to turbine seal o-ring friction
– No returns -9’s, noted for, primary cause, to date
Logistics
. SB 80-1756 offers no charge upgrade to dash 9, chg #1
–
Offer expires Dec 31, 2006
–
Honeywell R&O shops in Anniston, Raunheim and Singapore set up tosupport this SB
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-101 HONEYWELL CONFIDENTIAL
Page 101
Issue # 2
. Turbine Bearing Failure
– Causes No Start (Engine fails to motor)
.
Metal may be present on magnetic drain plug
.
White smoke during engine starts
.
Oil dripping from starter exhaust screen
Root Cause
. Loose turbine stack condition
–
Axial spline interference between turbine wheel shaft and sun gear
–
Turbine nut shims can get trapped in threads
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-102 HONEYWELL CONFIDENTIAL
Page 102
Root Cause
.
Two failure modes have been identified
–
Axial Spline Interference Between Turbine Shaft And Sun Gear
–
Turbine Nut Shims Can Be Trapped in Turbine Wheel Threads DuringAssembly
.
Both failure modes prevent turbine retaining nut from applyingproper pre-load across turbine bearing through turbine shaft
– Insufficient pre-load caused turbine thrust bearing failure leading toturbine seal failure
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-103 HONEYWELL CONFIDENTIAL
Page 103
Resolution
. Minor design changes to turbine stack preclude the failure modes
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-104 HONEYWELL CONFIDENTIAL
Page 104
Resolution
.
Revised turbine stack
–
Modified turbine wheel shaft
–
New sun gear
–
New turbine nut
–
New shims
.
Also new turbine seal and overrun bearing spring
Status
.
SB 80-1762 released September 2002
–
Includes revised stack, new turbine seal new overrunning bearingpreload spring
. Eliminates spring unseating causing OPS decoupling
–
Applies to -7, -8, & -9, mods all to dash 10
.
Modification to be introduced in 3505945-10 configuration
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-105 HONEYWELL CONFIDENTIAL
Page 105
Benefit
. Eliminate turbine bearing failure due to loose turbine stack
Logistics
.
SB 80-1762 offers upgrade to dash 10, kit p/n 3507696-1
.
50% rebate on kit price offered if old turbine wheel and spurgears are returned to Honeywell
.
Honeywell R&O shops in Anniston, Raunheim and Singaporeset up to support this SB
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-106 HONEYWELL CONFIDENTIAL
Page 106
Note: 3505945-9 Configuration with Added Inspection Addresses Turbine Pre-load and Seal Issues for Fielded Units
Turbine Wheel Stretch
.
Improved turbine seal eliminatesInspection Toolstarter oil leakage due to seal o-ringfriction
– Number one cause of starter failures
.
Turbine stretch inspection procedureensures that turbine wheel and bearing have proper pre-load
– Special tooling has been developed to
accomplish this inspection
.
Current -7 and -8 starters to be upgraded to -9 on First Shop Visit, SB80-1756 Released June 2002
All Starters Repaired at Honeywell Since September 2002 of -9 Must
Meet the Pre-load Inspection Crit
eria to Eliminate Stack Issue
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-107 HONEYWELL CONFIDENTIAL
Page 107
.
Summary
–
3505945-9, (P09)
.
First production 3505945-9, July 2002
.
Incorporates new turbine seal
–
3505945-10, (P10)
.
First production 3505945-10, August 2002
.
Incorporates updated turbine stack
.
Modified turbine wheel shaft
.
new sun gear
.
new turbine nut
.
new shims
.
New overrunning bearing preload spring
.
Support Plan
–
Current -7 and -8 starters recommended to be upgraded to -9 on nextshop visit
–
Dash 10 customer option
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-108 HONEYWELL CONFIDENTIAL
Page 108
Platform: B737-300/-400/-500
Bob Gildenstern Sr. Customer Service Engineer FSCM/Cage Code 59364, ESA Tempe AZ
Trace Data through September 2003 Fleet MTBUR = 7,139 hrs Percent Reporting = 31%
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-109 HONEYWELL CONFIDENTIAL
Page 109
# 1 Issue
. Oil leak number one field removal cause
– 58% of returns in last 12 months caused by output shaft sealleakage
Root Causes
.
Failure of secondary seal in Carbon seal assembly
.
Manufacturing variation in seal rotor perpendicularityand flatness
.
Manufacturer variation in clutch friction
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-110 HONEYWELL CONFIDENTIAL
Page 110
P/N 3505716
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-111 HONEYWELL CONFIDENTIAL
Page 111
Solution
. Redesigned carbon seal assembly
–
Improved seal diaphragm
.
GLT elastomer replaces Viton A elastomer for HTS oil compatibility
.
Higher heat capabilities
–
Same dimensions as diaphragm used in current configuration
–
Resists tears due to a Nomex mesh that is molded in the compound.
–
Proven results on applications (B777, B747, SAAB 2000)
Diaphragm
Carbon Seal
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-112 HONEYWELL CONFIDENTIAL
Page 112
Solution (Cont)
.
Redesigned carbon seal rotor
– Reduces tolerances on perpendicularity and surface finish
.
Based on pre-1998 inspected hardware
.
Improves ability to track which decreases leakage
.
Reduces local heat generation to decreased coke build-up
.
Reduces blistering of Carbon element
.
Low drag clutch implemented on a“As Required Bases”
–
Reduces oil temperature
. Prolongs life of diaphragm
–
Clutch replaced only when existing clutch damaged
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-113 HONEYWELL CONFIDENTIAL
Page 113
Status
.
Service Bulletin 3505716-80-1729 incorporates PN 3505716-6,(Series 6 new production), (Change 6 field mod)
–
Released June 2002
–
No new diaphragm failures noted to date, Jan. 23, 2004
.
NOTE: Improved Carbon seal and HTS elastomers to beimplemented in Starter PN 3505526 (pawl and ratchet clutch)
– Second Quarter 2004
.
Decreases starter oil leakage failures
Benefit
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-114 HONEYWELL CONFIDENTIAL
Page 114
Current Issue #2
. Some airlines requesting 3505716-6 starter’s to be HTS oilcompatible
Root Cause
. Existing elastomers not fully compatible with HTS oils
Solution
. Replace all elastomers with HTS compatible materials
Status
.
SB 80-1749 to add HTS compatible elastomers
.
Submitted to Boeing for approval
.
SB release estimated second Qtr 04
.
Series/change mod re-identification
Use or disclosure of information contained on this page is subject to the restrictions on the cover. V04-166-115 HONEYWELL CONFIDENTIAL
Page 115
| 欢迎光临 航空论坛_航空翻译_民航英语翻译_飞行翻译 (http://bbs.aero.cn/) | Powered by Discuz! X2 |