CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster spool lugs CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster lug BACKGROUND 冪 OVERVIEW OF CONCERNED AREA BOOSTER LUG USED FOR PLATFORM ATTACHMENT CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster lug BACKGROUND 冪 Lug liberation encountered during rig test Test conducted for platform modification substantiation Lug failure after 18374 cycles. Parts not completely representative of production (Hole shot peening) CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster lug BACKGROUND 冪 Field experience PCA engine (SWA 7733 hours/6145 cycles) inspected. 刋 Mark area with light fretting surrounding each hole. 刋 Visual inspection, FPI and ECI within the hole revealed no finding/no indications. 刋 3 lugs found with surface micro-crack on contact surface . 1 crack of 0.5mm (0.02 inch) found through detailed microscope inspection (not detectable by ECI) . 2 cracks of 0.8mm through ECI . All cracks located in fretting area on the contact surface at about 3oˇclock Engine 875- 297( 4642 hours/2150 cycles) 刋 no finding after ECI within the hole Engine 874-163 (6401 hours/6164 cycles) 刋 no finding through ECI inspection CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster lug BACKGROUND 冪 Development engine test experience : fleet leader booster spool ~9550 cycles ECI within the hole , FPI and visual inspection revealed no indications Spool used to run 90 000 cycles rig test CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited ENGINEERING INVESTIGATIONS 冪 Comprehensive program performed to confirm root cause and define short term (field plan), intermediate fix in production and long term redesign Finite element model analysis Rig testing: 4 rig tests performed rig number accumulated cycles speed booster configuration 1 18 374 +10% of the RL radial load levels flange not completely representative of field configuration 2 21 626 redline booster spool representative of field configuration 3 90 000 redline pizza pie configuration:field configurations and improvements 4 46 504 redline PCA booster pizza pie configuration:field configurations and improvements Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited ROOT CAUSE 冪 Analysis shows that the damages are related to flange bending leading to crack initiation and propagation. centrifugal load from platform results in: High bending stress Bending and associated relative displacement results in fretting in contact surface in high stressed area (lug forward contact face) 冪 Damage only related to LCF loading. No HCF stress in this area (measurement performed during engine development test) Flange bending Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited FAILURE CONSEQUENCES 冪 Rig tests , specimen tests and calculation show that crack propagations lead to lug outer parts failure and platform liberation. The prime integrity of the booster spool is not affected. Lugs are not part of the prime load carrying rotating structure Outer part Inner part Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited FAILURE CONSEQUENCES (conˇt) 冪 If platform liberation occurs, liberated hardware containment has been demonstrated through Trajectory and energy analysis During development test with complete platform liberation. 刋 Large bird ingestion test 刋 Fan blade out test Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited IMPROVEMENTS 冪 Counter-weight installation : Counterbalance moment due to platform centrifugal load Minimize flange bending Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited CORRECTIVE ACTIONS 冪 Field plan Counter-weight installation at next fan blade lubrication opportunity 刋 Counter-weight installation before 7000 cycles . No on wing ECI inspection required at installation . Mandatory inspection required above 15000 cycles, not to exceed 20000 cycles (one time) 刋 Counter weight installation after 7000 cycles . On wing ECI inspection required at installation 刋 Parts with ECI indications :Over-serviceability to be defined 刋 Mandatory inspection required above 15000 cycles, not to exceed 20000 cycles (one time) Counter-weight installation to be performed no later than 11000 cycles SB 72 0296 for counter weight installation and SB 72 0295 for lug ECI Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster lug CORRECTIVE ACTIONS 冪 Field plan (contˇd) Inspection thresholds ECI at counter weight installation ECI beween 15 000 cycles and 20 000 cycles if counter weight installed since new no no if counter weight installed before 7000 cycles no yes if counter weight installed after 7000 cycles and before 11 000 cycles yes yes CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited CORRECTIVE ACTIONS 冪 Production Interim action for production 刋 Introduction of counter weight until thickened flange available 刋 No inspection required for this configuration (minimum initiation life 37 000 cycles) Final fix 刋 Introduction of thickened lug Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Field solution and intermediate production solution: Lug with counter weight Fix for production reinforced lug Booster lug CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, December 2000 WTT face to face or Export are Prohibited Booster lug SCHEDULES 冪 Interim action for production CAD in review at the agencie SB 72-0295 &72-296 in process 刋 counter-weight available for production and field- December 2000. 冪 Final fix with thickened lug First part available 2nd quarter of 2001作者: kinran 时间: 2011-6-4 22:37:41
