标题: CFM Ignition System Reliability [打印本页] 作者: 航空 时间: 2011-4-16 11:40:35 标题: CFM Ignition System Reliability
作者: 航空 时间: 2011-4-16 11:40:50
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 1 Ignition System Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 2 Ignition System Reliability • Ignition System is third leading cause of D&Cs - Behind HMU HPSOV switches and FMV faults - Includes A/C start brake assembly, A/C and engine harnesses, EEC, exciter, lead and plug - Engine hardware excluding plugs continues to be No Fault Found • CFMI and Boeing studied 117 Event Reports (1-98 to 7-00) - 58 of these events resulted in D&Cs • Data typically insufficient for exact causal determination - Squawks were intermittent, no follow up reports, plug time not tracked • Based on the E/R narrative and a predetermined set of ground rules, the team assigned cause as: - Ignitor plug - A/C switch (start brake) - Can’t determine - Other February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 3 Potential Improvement Areas for Ignition System Dispatch Reliability • Improved Troubleshooting EEC SW version 7.B.M1 - FIM procedure 80-06, tasks 801 through 805 • Use of Input Monitoring to determine if switches are in commanded state D & Cs by Ignition Side Right Left 57% 23% Can't Tell 16% Both 4% Breakdown of Ignition SystemD&C's Suspect Plug 27% Suspect Switch 33% Can't Tell 22% Other 18% Ignition D&C Repeats D&C Repeat 16% No D&C Repeat 84% Ignition System Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 4 Potential Improvement Areas for Ignition System Dispatch Reliability • Plug Soft Time - Significant improvement, recommend 1000 cyc (CESM 006, revision 3) • Plug costs ~ 25¢ per engine cycle vs thousands of dollars per D&C - Unison offers a service to its customers to determine if there is significant life remaining on igniter plugs (FEB-2002 FHA) • Adjust soft time depending on results • For $9 per plug, part will be assessed for life remaining » If 50% or more life remains, plug will be returned to customer » If less than 50% life remains, part will be scrapped • Send plugs only in groups of 25 or more to » P.O. required Unison Industries ATTN: Debbie Reid 7575 Baymeadows Way Jacksonville, FL 32256 Ignition System Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 5 Potential Improvement Areas for Ignition System Dispatch Reliability • A/C Start Brake Assembly - Significant Improvement - Refer to Boeing Service Letter 737-SL-76-020 and Maintenance Tip 737MT73-001 • A/C Automatic Ignition Transfer Relay Option - Boeing offers an option that allows dispatch with an inoperative right ignition system but does not require opening the fan cowls • Contact your Boeing Customer Engineering representative for production cost and availability information • Contact Boeing Airplane Services for retrofit cost and availability information at airplaneservices@boeing.com - Reduce D&Cs 30+ percent Ignition System Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 6 CFM56-7B Fleet - Engine Cycles 0 50 100 150 200 250 300 350 0 50 100 150 200 250 300 350 Number of Engines ECSN Distribution作者: kinran 时间: 2011-6-4 23:12:19
