LPC Stage 5 Blade failure US Airways / CFMI April 12th, 2001
**** Hidden Message ***** This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 1<BR>LPC Stage 5 Blade failure<BR>US Airways / CFMI<BR>April 12th, 2001<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 2<BR>Overview<BR>• ESN 779761 CFMI Investigations Report<BR>• Production Quality Investigation<BR>• Engineering Analysis<BR>• Field Investigations<BR>• Field Program<BR>• General Summary<BR>• Appendix 1<BR>Axial Wave Description<BR>• Appendix 2<BR>On-wing / Shop Inspection Findings<BR>• Appendix 3<BR>CFM56-5A Booster Radial Clearance - Past Experience<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 3<BR>ESN 779761 CFMI Investigations Report<BR>• Contents<BR>每 Background<BR>每 ESN 779761 - LPC Blade Stage 5 Failures<BR>每 Investigation Summary<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 4<BR>Background<BR>• August 30th, 2000. During climb at ~1000 ft., crew reported 3 audible stalls from right engine. No engine<BR>parameter changes reported, no ECAM or fault messages. Throttle retarded to idle, then increased to climb<BR>power with no abnormal response.<BR>• Passengers and crew in cabin reported flashes coming from the engine. A TWA flight departing behind the<BR>A/C reported seeing fire from the engine exhaust area.<BR>• Crew elected to return to field, uneventful landing. Ground visual inspection found NO SIGNS of FOD/bird<BR>ingestion, fan turned freely. .<BR>• After landing, investigation revealed booster/compressor damage. Engine disassembly confirmed 2 LPC<BR>Stage 5 blade failures.<BR>• Additional, investigations performed at CFMI confirmed 2 more cracked blades (same location than crack<BR>initiation on broken blades)<BR>• Engine TSN/CSN: 524/253<BR>• Note 1: FOD has been reported during Flight 4 at AIRBUS/CFMI assembly line<BR>每 BSI performed did not revealed any damage at the Stage 5 area, 2 fan blades have to be replaced<BR>• Note 2: No abnormal engine behavior (during revenue service) reported prior to this event<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 5<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>1 - Suction face<BR>2 - Fatigue rupture initiated on suction face<BR>Failed blade # 1<BR>Origin<BR>Origin<BR>HCF<BR>Beach marks<BR>Note : No reinitiation after each beach marks which cannot be considered as arrest lines<BR>30/11/2000<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 6<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>Failed blade # 2<BR>1 - Suction face<BR>2 - Fatigue rupture initiated on suction face<BR>Origin<BR>Origin<BR>HCF<BR>Beach marks<BR>Note : No reinitiation after each beach marks which cannot be considered as arrest lines<BR>30/11/2000<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 7<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>Cracked blade # 3<BR>1 - Suction face<BR>2 - Fatigue rupture initiated on suction face<BR>Origin<BR>Origin<BR>HCF<BR>Beach marks<BR>Note : No reinitiation after each beach marks which cannot be considered as arrest lines<BR>30/11/2000<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 8<BR>• FPI on LPC Stage 5 blades (except the 3 lab. Investigated blades)<BR>每 2 (more) cracked blades, mid chord, suction face, about 3 mm from platform (same location than crack initiation<BR>on 3 broken blades)<BR>• 1 crack : 1 mm<BR>• 1 crack : 20 mm<BR>每 Many secondary cracks due to impacts on airfoils<BR>• Visual Inspection on LPC Stage 5 blade<BR>每 Heavy wear on every blade tips, mainly from mid chord to TE, and many TE tip curls, due to rubbing on broken<BR>blade "blocked up" on stator abradable. Blade length cannot be established, some blades are bent near<BR>platform from pressure face to suction face, due to the same reason.<BR>每 About 20 leading edge tip curls from pressure face to suction face.<BR>每 Fretting on many root pressure faces.<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 9<BR>• Stage 5 Booster Stator<BR>每 Visual Inspection<BR>• Abradable damaged area located at 06:30<BR>• Rubbing all around the track showing 8 waves (see dimensional inspection on next sheet) more<BR>pronounced TE area<BR>• Secondary damages due to blade ruptures : impacts, rubbing,...<BR>• Abradable Inspection<BR>每 Micro analysis on a damage area<BR>• 1st analysis : no anomaly found on samples (no pollution)<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 10<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>- ABRADABLE DIMENSIONAL INSPECTION<BR>451,000<BR>452,000<BR>453,000<BR>454,000<BR>455,000<BR>456,000<BR>0<BR>5 10 15 20 25<BR>30<BR>35<BR>40<BR>45<BR>50<BR>55<BR>60<BR>65<BR>70<BR>75<BR>80<BR>85<BR>90<BR>95<BR>100<BR>105<BR>110<BR>115<BR>120<BR>125<BR>130<BR>135<BR>140<BR>145<BR>150<BR>160155 175170165<BR>180<BR>195190185 205200<BR>210<BR>215<BR>220<BR>225<BR>230<BR>235<BR>240<BR>245<BR>250<BR>255<BR>260<BR>265<BR>270<BR>275<BR>280<BR>285<BR>290<BR>295<BR>300<BR>305<BR>310<BR>315<BR>320<BR>325<BR>330<BR>335340345350355<BR>• STAGE 5 BOOSTER VANE<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 11<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>1 - Abradable damaged area at 06:30<BR>2 - 8 wave rubbing on abradable<BR>Abradable wave wear pattern<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 12<BR>• Stage 5 Booster Vane<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>1 - Inner diameter :<BR>abradable black<BR>discoloration in<BR>damaged area<BR>2 - Outer diameter :<BR>thermal discoloration<BR>Cross section in the damaged area<BR>1<BR>2<BR>Melted area<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 13<BR>• Stage 5 Booster Vane<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>Cross section in the damaged area<BR>1 - Correct structure of METCO 601<BR>2 - Damaged area : no corrosion or<BR>oxidization sign<BR>3 - Melted area on surface<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 14<BR>• Stage 5 Booster Vane<BR>ESN 779761 每 LPC Blade Stage 5 Failures<BR>1 - Microscopic examination on an outer ring cross<BR>section, far from the discolored area : correct structure<BR>2 - Microscopic examination in a discolored area :<BR>no structure transformation<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 15<BR>Investigation Summary<BR>• The two LPC stage 5 blades failures are the consequences of the crack evolutions<BR>initiated in the airfoil convex side few millimeter up from the platform<BR>• Three other blades were also found cracked, with one with the airfoil almost liberated<BR>• The cracks initiation occurred under high stress, their propagation took place under<BR>high cycle fatigue in association with low static and dynamic stress<BR>The blades have been submitted to a flexion/torsion mode, this fact can be generated by<BR>sudden wear contact on TE blade tips<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 16<BR>Production Quality Investigation<BR>• Contents<BR>每 Process for F71 Calculation<BR>每 Production F71 Clearance Data<BR>每 US Airways Production F71 Clearance Data Summary Sheet (Sample Method)<BR>每 US Airways Production F71 Clearance Data<BR>每 LPC Blade Production Quality Investigation<BR>每 US Airways Potentially Affected Fleet<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 17<BR>Process for F71 Calculation<BR>• 1 out of 10 modules are measured<BR>每 Sampling method applied since ESN 779-585<BR>• Before 100% assembled booster measurement were performed (3D process with blades secured in<BR>position)<BR>• Analysis of rotor diameter measurement process :<BR>每 Procedure<BR>• Stator<BR>每 Tri-dimensional measurement performed on 18 points (9 Diameters) on 1 Plane<BR>» Min., Max., Average diameters are considered<BR>• Rotor<BR>每 Measurement performed using a low speed balance machine (Rotor in rotating conditions, 1000<BR>RPM)<BR>每 Laser measurement performed bladed rotor on 1 Plane (Same plan as Stator)<BR>» The Laser machine is recording all the radius value, then for each blade and its 180∼ opposite<BR>a Diameter is calculated<BR>» Min., Max., Average diameters are calculated by machine software<BR>• F71 Calculation<BR>每 Mini Clearance Diameter Method<BR>» F71 = (Dia. Mini. STATOR - Dia. Maxi. Rotor) / 2<BR>» Comments: Leads to miss potential local over-length, indeed, a over-length blade in<BR>association with its opposite shorter can lead to a F71 within limits<BR>每 Forth coming method, Radius method<BR>» F71 = Mini. Radius STATOR - Max. Radius Rotor<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 18<BR>Process for F71 Calculation (Cont＊d)<BR>Blade Raduis<BR>452,00<BR>452,10<BR>452,20<BR>452,30<BR>452,40<BR>452,50<BR>452,60<BR>452,70<BR>452,80<BR>452,90<BR>1<BR>2 3 4 5<BR>6<BR>7<BR>8<BR>9<BR>10<BR>11<BR>12<BR>13<BR>14<BR>15<BR>16<BR>17<BR>18<BR>19<BR>20<BR>21<BR>22<BR>23<BR>24<BR>25<BR>26<BR>27<BR>28<BR>29<BR>30<BR>32 31 34 33<BR>35<BR>37 36 39 38<BR>40<BR>41<BR>42<BR>43<BR>44<BR>45<BR>46<BR>47<BR>48<BR>49<BR>50<BR>51<BR>52<BR>53<BR>54<BR>55<BR>56<BR>57<BR>58<BR>59<BR>60<BR>61<BR>62<BR>63<BR>64<BR>65 66 67 68<BR>Blade Raduis<BR>Maxi. Diameter<BR>Mini. Diameter<BR>ESN 779-761<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 19<BR>Production F71 Clearance Data (Cont＊d)<BR>F71 Clearances Distribution Calculated using the Diameter Method<BR>1,46<BR>1,411,41<BR>1,35<BR>1,33<BR>1,36<BR>1,29<BR>1,41<BR>1,36<BR>1,27<BR>1,30<BR>1,34<BR>1,30<BR>1,32<BR>1,28<BR>1,30<BR>1,33<BR>1,44<BR>1,26<BR>1,53<BR>1,28<BR>1,42<BR>1,25<BR>1,18<BR>1,23<BR>1,181,18<BR>1,251,25<BR>1,23<BR>1,28<BR>1,18<BR>1,16<BR>1,18<BR>1,211,22<BR>1,26<BR>1,24<BR>1,10<BR>1,24<BR>1,22<BR>1,19<BR>1,10<BR>1,20<BR>1,30<BR>1,40<BR>1,50<BR>1,60<BR>779-411<BR>779-552<BR>779-583<BR>779-585<BR>779-604<BR>779-622<BR>779-658<BR>779-937<BR>779-668<BR>779-685<BR>779-684<BR>779-693<BR>779-951<BR>779-707<BR>779-717<BR>779-954<BR>779-750<BR>779-744<BR>779-761<BR>779-959<BR>779-769<BR>779-783<BR>779-960<BR>779-797<BR>779-833<BR>779-843<BR>779-876<BR>779-885<BR>779-977<BR>575-109<BR>575-114<BR>779-984<BR>575-129<BR>575-137<BR>575-148<BR>575-153<BR>575-158<BR>575-168<BR>575-181<BR>575-182<BR>575-192<BR>MRB 15W06597-A<BR>Stator Steel Configuration (S/B 72-0351)<BR>MRB issued<BR>Production MRB<BR>Sampling<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 20<BR>Production F71 Clearance Data (Cont＊d)<BR>F71 Clearances Distribution Calculated using the Radius Method<BR>1,25<BR>1,27<BR>1,24<BR>1,17<BR>1,33<BR>1,23<BR>1,17<BR>1,19<BR>1,22<BR>1,16<BR>1,23<BR>1,148<BR>1,0991,104<BR>1,269<BR>1,074<BR>1,38<BR>1,171<BR>1,27<BR>1,14<BR>1,04<BR>1,151,15<BR>1,07<BR>1,09<BR>1,12<BR>1,16<BR>1,2<BR>1,081,08<BR>1,13<BR>1,111,12<BR>1,19<BR>1,12<BR>1<BR>1,15<BR>1,09<BR>0,9<BR>1<BR>1,1<BR>1,2<BR>1,3<BR>1,4<BR>1,5<BR>779-411<BR>779-552<BR>779-583<BR>779-585<BR>779-604<BR>779-622<BR>779-658<BR>779-937<BR>779-668<BR>779-685<BR>779-684<BR>779-693<BR>779-951<BR>779-707<BR>779-717<BR>779-954<BR>779-750<BR>779-744<BR>779-761<BR>779-959<BR>779-769<BR>779-783<BR>779-960<BR>779-797<BR>779-833<BR>779-843<BR>779-876<BR>779-885<BR>779-977<BR>575-109<BR>575-114<BR>779-984<BR>575-129<BR>575-137<BR>575-148<BR>575-153<BR>575-158<BR>575-168<BR>575-181<BR>575-182<BR>575-192<BR>Stator Steel Configuration (S/B 72-351)<BR>Production MRB<BR>MRB 15W06597-A<BR>MRB issued<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 21<BR>Production F71 Clearance Data (Cont＊d)<BR>• Additional investigation performed on the used production toolings<BR>每 Rotors have been measured using the dynamic (balance machine + laser measurement) & static tool (3 D<BR>machine)<BR>• Objective<BR>每 Ensure repeatability of measurements with dynamic device<BR>每 Ensure proper position of laser on rotor versus stator<BR>每 Correlation review between Static and dynamic method<BR>• Findings<BR>每 Repeatability of measured confirmed within 0.015 mm (0.000590§)<BR>每 The laser ※head§ is position in the same plane as the one on the stator, in another words the F71<BR>calculation is performed on the same plan<BR>» Since the flow path is conical any deviation may impact the final F71 calculation<BR>每 Correlation review between Static and dynamic method has been performed<BR>» It was noticed that the F71 calculation with balance machine/laser is resulting in a<BR>clearance that is tighten versus the 3D process (with blade secure in position) by 0.10 mm<BR>to 0.15 mm (0.00394§ to 0.000590§)<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 22<BR>Production F71 Clearance Data<BR>F71 Clearances Distribution Calculated using the Radius Method<BR>1,351,37<BR>1,34<BR>1,27<BR>1,43<BR>1,33<BR>1,271,29<BR>1,32<BR>1,26<BR>1,33<BR>1,248<BR>1,1991,204<BR>1,369<BR>1,174<BR>1,48<BR>1,271<BR>1,37<BR>1,24<BR>1,14<BR>1,251,25<BR>1,171,19<BR>1,22<BR>1,26<BR>1,3<BR>1,181,18<BR>1,231,211,22<BR>1,29<BR>1,22<BR>1,1<BR>1,25<BR>1,19<BR>0,90<BR>1,00<BR>1,10<BR>1,20<BR>1,30<BR>1,40<BR>1,50<BR>1,60<BR>779-411<BR>779-552<BR>779-583<BR>779-585<BR>779-604<BR>779-622<BR>779-658<BR>779-937<BR>779-668<BR>779-685<BR>779-684<BR>779-693<BR>779-951<BR>779-707<BR>779-717<BR>779-954<BR>779-750<BR>779-744<BR>779-761<BR>779-959<BR>779-769<BR>779-783<BR>779-960<BR>779-797<BR>779-833<BR>779-843<BR>779-876<BR>779-885<BR>779-977<BR>575-109<BR>575-114<BR>779-984<BR>575-129<BR>575-137<BR>575-148<BR>575-153<BR>575-158<BR>575-168<BR>575-181<BR>575-182<BR>575-192<BR>100%Booster Dim. Inspection - 3D Process<BR>Stator Steel Configuration (72-351)<BR>Production MRB<BR>F71 Clearance Corrected value<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 23<BR>US Airways Production F71 Clearance Data Summary Sheet (Sample Method)<BR>ESN Mod<BR>Ref. F71 Min. F71 Average F71 max. F71 mini F71 moyen F71 maxi<BR>575-109 AJ1880 1,23 1,35 1,47 1,16 1,35 1,51<BR>575-114 AJ1890 1,28 1,42 1,55 1,2 1,41 1,65<BR>575-129 AJ1910 1,16 1,26 1,38 1,08 1,26 1,47<BR>779-604 AJ1520 1,33 1,49 1,59 1,27 1,48 1,68<BR>779-658 AJ1590 1,29 1,40 1,55 1,17 1,41 1,61<BR>779-693 AJ1640 1,34 1,46 1,60 1,22 1,46 1,64<BR>779-707 AJ1660 1,32 1,49 1,64 1,23 1,52 1,71<BR>779-717 AJ1670 1,28 1,41 1,51 1,15 1,41 1,66<BR>779-761 AJ1719 1,26 1,39 1,51 1,07 1,39 1,76<BR>779-833 AJ1800 1,23 1,33 1,45 1,15 1,33 1,56<BR>779-876 AJ1850 1,18 1,29 1,40 1,07 1,28 1,52<BR>F71 Clearances Distribution Calculated F71 Clearances Distribution Calculated using the Diameter Method using the Radius Method<BR>Steel Stator Configuration (72-0351)<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 24<BR>US Airways Production F71 Clearance Data (3D Process)<BR>ESN TSN CSN Booster<BR>Ref. F71 mini F71 maxi mini maxi<BR>779-389 2521 3471 AJ1289 1,35 1,515 1,32 1,87<BR>779-401 8065 3869 AJ1302 1,555 1,715 1,32 1,87<BR>779-410 8065 3869 AJ1310 1,520 1,690 1,32 1,87<BR>779-411 7136 3403 AJ1311 1,455 1,580 1,32 1,87<BR>779-412 4901 2282 AJ1312 1,485 1,700 1,32 1,87<BR>779-413 8256 3948 AJ1316 1,515 1,660 1,32 1,87<BR>779-414 8223 3861 AJ1314 1,590 1,780 1,32 1,87<BR>779-415 8223 3861 AJ1315 1,370 1,565 1,32 1,87<BR>779-416 8196 3713 AJ1313 1,450 1,640 1,32 1,87<BR>779-430 7840 3445 AJ1330 1,550 1,705 1,32 1,87<BR>779-431 7840 3445 AJ1331 1,515 1,765 1,32 1,87<BR>779-436 3931 1716 AJ1337 1,485 1,695 1,32 1,87<BR>779-437 7711 3452 AJ1338 1,490 1,705 1,32 1,87<BR>779-440 7105 2908 AJ1340 1,615 1,750 1,32 1,87<BR>779-441 7105 2908 AJ1341 1,420 1,620 1,32 1,87<BR>779-454 7414 3306 AJ1352 1,530 1,765 1,32 1,87<BR>779-455 7414 3306 AJ1357 1,520 1,725 1,32 1,87<BR>779-456 7589 3386 AJ1355 1,450 1,620 1,32 1,87<BR>779-457 7589 3386 AJ1356 1,510 1,680 1,32 1,87<BR>779-465 4609 1879 AJ1373 1,555 1,710 1,32 1,87<BR>779-470 7181 3113 AJ1376 1,475 1,615 1,32 1,87<BR>779-498 5231 3036 AJ1397 1,430 1,605 1,32 1,87<BR>779-499 5231 3036 AJ1400 1,550 1,670 1,32 1,87<BR>779-500 6953 3031 AJ1401 1,440 1,575 1,32 1,87<BR>779-501 6953 3031 AJ1403 1,495 1,705 1,32 1,87<BR>Diameter Calculation Method Tolerances<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 25<BR>US Airways Production F71 Clearance Data (3D Process)<BR>ESN TSN CSN Booster<BR>Ref. F71 mini F71 maxi mini maxi<BR>779-508 4075 3677 AJ1411 1,355 1,520 1,32 1,87<BR>779-509 4075 3677 AJ1412 1,420 1,585 1,32 1,87<BR>779-522 2684 2683 AJ1428 1,410 1,615 1,32 1,87<BR>779-523 3605 3898 AJ1425 1,455 1,640 1,32 1,87<BR>779-528 6547 2889 AJ1433 1,430 1,620 1,32 1,87<BR>779-529 6547 2889 AJ1434 1,445 1,565 1,32 1,87<BR>779-536 3475 3855 AJ1443 1,385 1,505 1,32 1,87<BR>779-537 3475 3855 AJ1444 1,395 1,625 1,32 1,87<BR>779-555 6055 2780 AJ1466 1,440 1,630 1,32 1,87<BR>779-556 6055 2780 AJ1468 1,380 1,555 1,32 1,87<BR>779-559 6107 2696 AJ1471 1,440 1,590 1,32 1,87<BR>779-560 6107 2696 AJ1472 1,380 1,595 1,32 1,87<BR>779-561 6106 2709 AJ1474 1,490 1,645 1,32 1,87<BR>779-562 6106 2709 AJ1448 1,380 1,575 1,32 1,87<BR>779-563 5924 2720 AJ1473 1,390 1,605 1,32 1,87<BR>779-564 5924 2720 AJ1476 1,395 1,605 1,32 1,87<BR>779-571 2795 1239 AJ1487 1,430 1,615 1,32 1,87<BR>779-573 3163 3864 AJ1482 1,365 1,640 1,32 1,87<BR>779-574 2491 1341 AJ1488 1,300 1,510 1,32 1,87<BR>779-575 5715 2632 AJ1489 1,505 1,625 1,32 1,87<BR>779-576 5715 2632 AJ1491 1,415 1,510 1,32 1,87<BR>779-577 5837 2623 AJ1490 1,460 1,620 1,32 1,87<BR>779-578 5837 2623 AJ1492 1,350 1,505 1,32 1,87<BR>779-579 2420 1092 AJ1493 1,405 1,580 1,32 1,87<BR>779-580 2790 1251 AJ1494 1,360 1,530 1,32 1,87<BR>779-583 2187 936 AJ1496 1,410 1,575 1,32 1,87<BR>779-584 4983 2175 AJ1499 1,425 1,600 1,32 1,87<BR>Diameter Calculation Method Tolerances<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 26<BR>LPC Blade Production Quality Investigation<BR>• 5 suspected blade batches identified for over-length<BR>End 1999 (Dec.) early 2000 (Feb.)<BR>每 Control process reinforced at vendor facilities<BR>• New inspection tool<BR>每 6 points inspection tool instead of<BR>Go no Go gage since May 2000<BR>每 Manufacturing purges incriminated batches from<BR>production shelf<BR>• Completed February 2000<BR>• ESN 779761 Failed blades issues from<BR>those suspected batches<BR>• Associated ESN equipped with pre-mentioned<BR>suspected blades identified<BR>每 188 Engines potentially impacted by over-length<BR>blades in the CFM56-5B fleet<BR>每 59 Engines potentially impacted by over-length<BR>blades, in US Airways Fleet<BR>• Additional work is in process to confirm the extant of<BR>the manufacturing lot of engines built with<BR>potentially over length blades<BR>每 Target date: April 2001<BR>Before After<BR>Identified Problem<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 27<BR>LPC Hardware Production Quality Investigation<BR>• LPC Booster Blade stage 5<BR>每 An in-situ audit was launched at the CFMI Blade manufacturer (April1st, 2001)<BR>• Blades were measured in CFMI Lab<BR>• Same blades were inspected by the blade manufacturer<BR>每 No discrepancy noticed between the two inspections<BR>• Stator<BR>每 2 configurations in the fleet Titanium, Steel (Refer to S/B 72-0351)<BR>• Production review for both configuration did not revealed any abnormal manufacturing deviation<BR>• Booster Spool<BR>每 MRB have been released on ESN 779-761, for axial position of the stage 5 LPC dovetail slot 0.015 mm /<BR>0.0006§<BR>• Considered as insignificant to the quality issue<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 28<BR>US Airways Potentially Affected Fleet<BR>ESN TSN CSN A/C Position<BR>779647 4577 2122 N725UW 2<BR>779651 2204 3035 N112US 1<BR>779652 2204 3035 N112US 2<BR>779653 4362 2052 N726US 1<BR>779654 4362 2052 N726US 2<BR>779657 3830 1761 N113UW 1<BR>779659 4398 2056 N727UW 1<BR>779660 4398 2056 N727UW 2<BR>779663 3699 1649 N114UW 1<BR>779664 3699 1649 N114UW 2<BR>779665 4161 1889 N728UW 1<BR>779683 3689 1711 N729US 2<BR>779691 3678 1651 N730US 1<BR>779692 3678 1651 N730US 2<BR>779693 2866 1239 N107US 2<BR>779695 3377 1529 N115US 1<BR>779696 3377 1529 N115US 2<BR>779701 3247 1564 N732US 1<BR>779702 3247 1564 N732US 2<BR>779706 3198 1478 N733UW 1<BR>779707 3198 1478 N733UW 2<BR>779710 3206 1449 N736US 1<BR>779711 3206 1449 N736US 2<BR>779716 2601 1184 N116US 1<BR>779717 2601 1184 N116US 2<BR>779730 2677 1139 N117UW 1<BR>779731 2577 1139 N117UW 2<BR>779746 2476 1209 N737US 1<BR>779747 2476 1209 N737US 2<BR>779756 2442 1213 N738US 1<BR>ESN TSN CSN A/C Position<BR>779757 2442 1213 N738US 2<BR>779760 2308 1160 N739US 1<BR>779762 873 1189 N104UW 1<BR>779763 1699 696 N118US 1<BR>779764 1699 696 N118US 2<BR>779767 2332 1111 N740UW 1<BR>779768 2332 1111 N740UW 2<BR>779771 2284 1100 N741UW 1<BR>779772 2195 1047 N743UW 1<BR>779775 1187 541 N123UW 1<BR>779776 N163US 1<BR>779777 2050 881 N119US 1<BR>779778 2050 881 N119US 2<BR>779779 2195 1047 N743UW 2<BR>779780 2284 1100 N741UW 2<BR>779784 1056 531 N729US 1<BR>779785 0 0 SPARE 0<BR>779795 950 462 N762US 2<BR>779808 1542 667 N121UW 2<BR>779831 1104 490 N124US 1<BR>779833 667 630 N753US 1<BR>779834 617 640 N753US 2<BR>779859 1119 534 N760US 1<BR>779863 958 482 N763US 1<BR>779864 958 482 N763US 2<BR>779865 0 0 SPARE 0<BR>779867 0 0 SPARE 0<BR>779871 1099 486 N764US 1<BR>779872 1099 486 N764US 2<BR>779873 235 117<BR>TBD<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 29<BR>Quality investigation Summary<BR>• F71 calculation process with the diameter may leads to miss potential local over-length<BR>• Radius method implemented in production since March 2001<BR>每 3D Process used<BR>每 100% Booster module inspected<BR>• LPC Hardware<BR>每 Blade<BR>• Confirmation of the adequacy of the n ew booster blade stage 5 inspection tool in place<BR>每 Remaining hardware investigation status did not revealed any timely manner manufacturing<BR>deviation<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 30<BR>Engineering Analysis<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 31<BR>Event / Findings Analysis<BR>• Engineeringanalysis indicates the unusual wave wear pattern of the stator can occurred only if blade<BR>untwists, otherwise, the contact/wear area would be located forward.In such condition the blade would<BR>have been submitted to a flexion mode similar to the one noticed on the CFM56-5A.<BR>• Additional external phenomenon (FOD, Stall,...) needed to initiate stress damages to the blade<BR>• Most probable failure scenario of ESN 779761<BR>每 Sudden engagement of LPC blade into the abradable<BR>• Phenomenon origin not consolidated<BR>• Blade untwist suspected based on abradable TE wear evidences<BR>每 High tensile stress to blade airfoil that leads to crack initiation<BR>每 HCF propagation & airfoil separation<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 32<BR>Engineering Summary<BR>• Additional external phenomenon (FOD, Stall,...) needed to initiate stress damages to the<BR>blade<BR>• BSI performed on US Airways suspect engines did not revealed any damage evidences<BR>( In revenue service & AIRBUS flight line engines)<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 33<BR>Field Investigations<BR>• Contents<BR>每 On-wing Inspection Methods<BR>每 US Airways BSI On wing & Shop Investigation Status<BR>每 Field Investigations Summary<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 34<BR>On-wing Inspection Methods<BR>• Linipot Procedure evaluation<BR>每 Testing revealed that we can ＊t installed the probe in proper position onto the blade<BR>每 It is not possible to check the booster Stage 5 abradable per this inspection tool<BR>• Procedure of abradable Stage 5 on-wing inspection without disassembly elaborated by SnS On-wing<BR>support Team<BR>每 Inspection of the booster rotor blades / casing through the borescope port S05.<BR>• This borescope port (S05) located (approximately) at the 3.30 o＊clock position at the periphery of the<BR>booster section and almost radially in line with the stage 5 of the booster stator. Through this port<BR>(S05), you can see the trailing edge of the booster stage 5 rotor blades.<BR>每 To do this inspection of the booster stage 5 rotor blades / casing :<BR>• 1 Use Fiberscope Set (856A1321 length 2.5 m (8ft 2in.) or equivalent<BR>• 2 Use borescope 每 Light source set (856A1322P02/P03/P04/P07/P08) or equivalent<BR>每 This procedure tested at CFM training school<BR>每 Inspection criteria<BR>• Axial wave rub = LPC removal<BR>每 More pronounced on T.E. area<BR>• Cracks or burns or heat discoloration = LPC Removal<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 35<BR>US Airways BSI On wing & Shop Investigation Status<BR>• On-Wing<BR>• Shop<BR>SNS USA No rub L/E rub<BR>2 779717 2813/1291 2813/1291 22-mars X CLT X<BR>1 779747 2724/2241 2724/2241 26-mars X PIT X<BR>2 779746 2724/2241 2724/2241 26-mars X PIT X<BR>1 779763 1933/798 1933/798 28-mars X CLT X<BR>2 779764 1933/798 1933/798 28-mars X CLT X<BR>1 779757 2661/1325 2661/1325 29-mars X PIT X<BR>2 779756 2661/1325 2661/1325 29-mars X PIT X<BR>1 575129 42/31 42/31 30-mars X CLT X<BR>2<BR>1 779775 1422/651 1422/651 30-mars X CLT X<BR>2<BR>A/C Pos ESN TSN/CSN TSI/CSI Date Inspector Findings<BR>738<BR>167<BR>123<BR>Location<BR>116<BR>737<BR>118<BR>Location<BR>No rub L/e rub Remarks<BR>779-583 SNS X<BR>779-682 GEAES X<BR>779-411 GEAES X<BR>779-873 GEAES X<BR>779-465 GEAES X<BR>779-604 GEAES X<BR>779-436 GEAES No Stg 5 BSI<BR>779-529 GEAES No Stg 5 BSI<BR>779-527 GEAES X<BR>779-687 GEAES X<BR>779-580 GEAES X<BR>Findings<BR>ESN<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 36<BR>Field Investigations Summary<BR>• BSI performed on US Airways engines did not revealed any damage evidences ( In revenue<BR>service & AIRBUS flight line engines)<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 37<BR>Control Program<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 38<BR>Control Program<BR>• On-wing control program<BR>每 Stage 5 blade & Abradable BSI<BR>• Inspection of the booster rotor blades / abradable through the borescope port S05<BR>每 General guide lines, will be consolidated in the coming Service Bulletin72-0391 to be issued by April2001<BR>• One time inspection<BR>每 1) First opportunity without interfering with revenue service<BR>• Subsequent inspection recommended to be accomplished when one of the following conditions applies<BR>每 (2) Engine had a high-speed stall. Borescope inspection is recommended within 10 cycles or 25<BR>hours (use the limit that is completed first).<BR>每 (3) Engine had a FOD such that:<BR>每 FOD event met conditions that requested a gaspath inspection (Refer to AMM, Chapter 72-00-00,<BR>Inspection/Check)<BR>每 Stage 3, 5 and 9 HPC blades inspection revealed some damage (any type)<BR>» Borescope inspection is recommended within 10 cycles or 25 hours after event<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 39<BR>General summary<BR>• One event since CFM56-5B E.I.S<BR>• Failure scenario established<BR>• Major contributor identified Over-length LPC Stage 5 blades<BR>每 Additional external phenomenon (FOD, Stall,...) needed to initiate stress damages to the blade<BR>• Affected population 188 engines, 59 US Airways<BR>每 Manufacturing record review still on-going to close the affected population.<BR>• Completed end of April 2001<BR>每 BSI performed on US Airways engines did not revealed any damage evidences<BR>( In revenue service & AIRBUS flight line engines)<BR>• Corrective action in place<BR>每 Production<BR>• LPC new manufacturing tools in place<BR>每 Recent in situ quality audit confirmed no conformity issue<BR>• Booster production<BR>每 100% inspection of booster assembly using ※radius§ method<BR>• Fleet recommendation :<BR>每 AOW to be released April 2001<BR>每 S/B 72-0391 Borescope inspection to be issued<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 40<BR>Appendix 1<BR>Axial Wave Description<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 41<BR>LPC STG5 Distributor<BR>Step<BR>Blade LPC 5<BR>Abradable<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 42<BR>Step<BR>Step<BR>Width increase<BR>Front stator 5<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 43<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 44<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 45<BR>Top of the Wave<BR>Width increase<BR>Width decrease<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 46<BR>Width decrease<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 47<BR>Front stator 5<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 48<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 49<BR>Front LPC Stator 5<BR>Light or no rub<BR>Heavy rub<BR>Step<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 50<BR>Step<BR>Front Stator Stg 5<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 51<BR>Appendix 2<BR>On-wing / Shop Inspection Findings<BR>• Contents<BR>每 779-717 On-wing Inspection results<BR>每 779-717 - Production Data<BR>每 ESN 779-756 - On-wing Inspection / ESN 779-757 - On-wing Inspection<BR>每 ESN 779-747 & 748 - On-wing Inspection / ESN 779-763 - On-wing Inspection<BR>每 ESN 779-764 - On-wing Inspection<BR>每 ESN 779-522 - Shop inspection<BR>每 ESN 779-604 - Shop inspection<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 52<BR>779-717 On-wing Inspection results<BR>• BSI shows 360∼ regular abradable rub<BR>• No wave rubbing observed<BR>• Engine released serviceable<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 53<BR>779-717 - Production Data<BR>452,000<BR>452,100<BR>452,200<BR>452,300<BR>452,400<BR>452,500<BR>452,600<BR>452,700<BR>452,800<BR>452,900<BR>1<BR>2 3 4 5<BR>6<BR>7<BR>8<BR>9<BR>10<BR>11<BR>12<BR>13<BR>14<BR>15<BR>16<BR>17<BR>18<BR>19<BR>20<BR>21<BR>22<BR>23<BR>24<BR>25<BR>26<BR>27<BR>28<BR>29<BR>30<BR>32 31 34 33<BR>35<BR>37 36 39 38<BR>40<BR>41<BR>42<BR>43<BR>44<BR>45<BR>46<BR>47<BR>48<BR>49<BR>50<BR>51<BR>52<BR>53<BR>54<BR>55<BR>56<BR>57<BR>58<BR>59<BR>60<BR>61<BR>62<BR>63<BR>64<BR>65 66 67 68<BR>Blade Radius<BR>Max. Diameter<BR>Min. Diameter<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 54<BR>ESN 779-756 - On-wing Inspection<BR>ESN 779-757 - On-wing Inspection<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 55<BR>ESN 779-747 & 748 - On-wing Inspection<BR>ESN 779-763 - On-wing Inspection<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 56<BR>ESN 779-764 - On-wing Inspection<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 57<BR>ESN 779-522 - Shop inspection<BR>• ESN 522 not listed in list of engine with LPC stage 5 issued suspect batches<BR>• Flex scope could not get into the positions outlined in the Snecma Services procedure.<BR>每 Inspectors went through the VBV doors and got some stills in 12 different clock positions.<BR>• No sign of any distress.<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 58<BR>ESN 779-604 - Shop inspection<BR>• No sign of any distress<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 59<BR>Appendix 3<BR>CFM56-5A Booster Radial Clearance - Past Experience<BR>• Content<BR>每 Background - Root Cause Investigation<BR>每 Corrective Actions - CFM56-5A/5B Comparison<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 60<BR>Background - Root Cause Investigation<BR>• Background<BR>每 Numerous cases of stage 4 booster blade damages in service in early 90 ＊s<BR>每 Type of damages<BR>=> Trailing edge tip corner missing<BR>=> Leading edge airfoil crack<BR>=> Booster blade failure<BR>每 Consequence of heavy rub on METCO 601 abradable material<BR>每 Cases often associated with particular events such as<BR>=> FOD / birdstrike<BR>=> High speed stall<BR>=> Vibration<BR>• Root Cause Investigation<BR>每 Cause identified to be excessive blade penetration into abradable, leading to :<BR>=>Overstress on booster blade airfoil root<BR>=>Various damages and potential failure<BR>Main contributors<BR>=>Too tight clearances<BR>=>Blade over length leading to too tight clearances<BR>=>Particular events such as FOD/birdstrike/high speed stall<BR>=>Steel blade locks and counter balance weights leading to evidence of booster spool ovalization<BR>This document and the information contained are CFMI property and shall not be copied nor disclosed to any third party without CFMI prior written authorization 61<BR>Corrective Actions - CFM56-5A/5B Comparison<BR>• Corrective Actions<BR>每 Shop level<BR>• Back in 1988<BR>每 S/B: 72-038<BR>» To reduce all stages blade length<BR>» Adds radius to blade leading edge tip<BR>» incorporated ESN 731-141 & up<BR>• 1989/90<BR>每 S/B: 72-100 / 185 to increase abradable land for stator stages 3 / 4<BR>» S/B 72-100 (Stage 3) Introduced ESN 731-202 & up<BR>» S/B 72-185 (Stage 4) Introduced ESN 731-318 & up<BR>• 1991<BR>每 At first booster exposure<BR>» S/B: 72-226 to inspect/rework stage 4 blade length<BR>• 1992<BR>每 S/B: 72-315 for stages 2/3/4 titanium blade locks introduction instead of steel (at customer option),<BR>introduced ESN 731-652 & up<BR>每 On wing control program<BR>• 1991<BR>每 S/B72-152 for on-wing borescope inspection of stage 3 and 4 blades<BR>• CFM56-5A/5B Comparison<BR>每 Booster spool design less subjected to ovalization due to presence of aft hub<BR>每 CFM56-5B booster spools equipped with titanium blade locks since EIS隙葩 1# 瑤諾 腔泃赽
CFM56-7B TRAINING MANUAL ENGINE FAN TRIM BALANCE :victory: :victory: LPC Stage 5 Blade failure US Airways / CFMI April 12th, 2001
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