Old 777 GE-90 engines to be checked

[CONSO]

FAA orders checks on a handful of 777 engines | The Seattle Times

FAA orders checks on a handful of 777 engines

Originally published January 11, 2016 at 3:28 pm

Following an uncontained engine failure and fire as a British Airways 777 jet took off in Las Vegas last September, the Federal Aviation Administration is initially mandating inspections of a small number of in-service engines. These are expected to be completed this week.

By Dominic Gates
Seattle Times aerospace reporter

Following an uncontained engine failure and fire as a Boeing-built British Airways 777 jet took off in Las Vegas last September, the Federal Aviation Administration (FAA) is initially mandating inspections of just six specific engines of similar age, configuration and usage flying in the U.S.

The engine involved in this first uncontained failure of any GE-90 was one of the first built for the initial 777s after 1995.
About 400 engines of this early GE-90 type are now in service on 167 airplanes. More recently built 777s have a different configuration.

[Data Guy]

Past ADs

It matters greatly what the NTSB’s metallurgical analysis will be. You may recall that right after Sioux City the FAA said the suspect ‘pool’ of the titanium Fan Disks was about 240. That didn’t work with ADs be added for years afterward. Meanwhile, here is a quick over view of compressor failure ADs in GE 90s, and as well, crossing into other model lines.

6 GE -90 Series Engine Compressor ADs. (Briefs only).

For Full AD and Details, Query By AD number at the FAA AD Query website;
Link > Airworthiness Directives

2013-24-17. - 90-110B1 and -115B HPC ROTOR, SPOOL SPACER ARMS, Stages 2-5. CRACKS FOUND.Prompted by reports of cracks in HPC rotor stage 2-5 spool aft spacer arms.
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2011-26-11. - 90- 110B1 and -115B HPC SPOOL SEAL TEETH, Stages 2-5. CRACKS FOUND.Prompted by aborted takeoff, liberation of small pieces, and two shop findings of cracks in the seal teeth.
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2011-15-06.- 90-76B, -77B; -85B; -90B; and -94B. HPC SPOOL, Stages 8-10 WELD JOINTS. Cracks Found.Prompted by cracks discovered on one HPCR 8-10 spool between the 9-10 stages in the weld joint.(Ed. Notes; Same as FAA-2010-1024.Prior ADs - AD-91-11-05 and 2002-04-11 CF6-80 series.
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2002-04-11. - 90-76B, -77B, -85B, -90B, -94B HPC SPOOL Stages 8-10 . WELD JOINTS and Disk Stages 1-6, 7, 9. Prompted by additional focused inspection procedures that have been developed by the manufacturer.(Also Turbine parts – See table).Revise manufacturer's Life Limits. Correction to AD 2000-08-10.Superceded by 2011-15-06, - HPC Stage 8-10 Weld Joints. Prior ADs - AD 2011-15-06 and 91-11-05 CF6-80 Series
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2002-01-27. - 90 series. HPC SPOOLS, Stages 2-6. CRACKS FOUND. Prompted by reports of cracks, Supersedes AD 98-15-03. …the introduction of a new design.
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98-09-15. - 90-76B HPC SPOOL, Stages 2-6. Reduced Life Limits. Prompted by refined life analysis by the manufacturer which revealed minimum calculated low cycle fatigue lives lower than the published low cycle fatigue retirement lives.
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CROSSING MODEL LINES. 15 OTHER GE MODEL COMPRESSOR ADs (- 45/50s, - 80s).

2009-14-08. -80C2B5F HPC Stages 11-14 SPOOL and SHAFTS before they exceed a new, reduced life limit. This AD results from an internal GE audit that compared the life limited parts certification documentation to the airworthiness limitations section.
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2009-07-03. - 80C2, and E1s HPCR SPOOL Stage 14 DISKS. CRACKS FOUND in 12 Disks.This AD results from reports of 12 HPCR spool shaft stage 14 disks with web cracks discovered to date.
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2009-04-10. - 80A, - C2, - E1, 80A, - C2, and E1s HPC Stages 1 to 14. Enhanced Inspections.This AD results from the need to require enhanced inspection of selected critical life-limited parts.
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2005-17-05. - 80C2 and - E1s HPCR SPOOL SHAFT Stages 11-14. Inspect for circumferential repair cuts. This AD results from an updated stress analysis.
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2002-25-08. -45s –50s - and - 80 SPOOLS Stages 3–9 . Inspect for cracks. This amendment supersedes three existing airworthiness directives (ADs 2000-16-12, 99-24-15, and 95-18-14)…aligns repetitive inspection requirements.(* Ed notes; ad makes no mention of connections to NTSB letter A-00-104 and prior incidents; (3 incidents, plus “the Board is aware of 10 others”.Also see 99-24-15.
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2002-25-08. – 45/50, and – 80s HPCR Spools, Stages 3-9. Supercedes ADs 2000-16-12, 99-24-15, and 95-18-14. Latter two not found in the FAA’s ADs Query Search; But refers to ADs, 2002-25-08, and 2000-11-12.
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2005-08-04. - 45 and -50 COMPRESSOR ROTOR Rear. Remove for exceeding the low-cycle fatigue limits. This AD results from an error in a tracking database that subtracted flight cycles of certain serial number parts from the actual accumulated cycles.
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2002-13-03. CFM56s,HPC SPOOL Stages 1-2, and Stage 3 Disk. (Also the Fan Disk and,Shaft, HPT Disk.Prompted by an FAA study of in-service events involving uncontained failures of critical rotating parts. Supercedes AD 2000-12-01.
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2002-05-03. CF6-6, -45, -50 HPC DISKS Stages 1 through 16. (Also the LPT shafts. Fan disks, Fwd and mid shafts.) (Prompted by) FAA study of in-service events involving uncontained failures. Supercedes AD 2000-08-11 11.
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2000-11-12. -45, - 50 COMPRESSOR Stage 14 disk lock slots. CRACKS FOUND. Inspections.Prompted by reports of stage 14 HPC disk lock slot cracks discovered during shop inspections. Issued on May 25, 2000. Effective on August 14, 2000.
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(Special Note) 6/16/00. FAA SERVICE DIFFICULTY REPORT. CF6 -50. COMPRESSOR SPOOL, Stages 11-14th CRACKED.Operator Designator DLOY; Boeing Shop Report (SDR). New Part 15 Months old. No Cause.SDR # & Link > 20000728SH009.
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99-24-15. - 50 and -80 series HPC Stages 3-9 SPOOL Disk Bores, Webs, Dovetail Slots.(Not Found In AD Query; superceded by 2002-25-08, and 2000-11-12).A result of NTSB Safety Recommendation Letter A-00-104; Link > http://www.ntsb.gov/safety/safety-recs/recletters/A00_104.pdf‘Three incidents - plus “ten others”.Also see 2002-25-08.
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97-22-14. -50 and -80C2, HPCR SPOOL Stages 3-9 DOVE TAILS,. CRACKS FOUND. Cause; oxygen stabilized Alpha particals.Prompted by a report of an uncontained failure of an HPCR stage 3-9 spool…
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95-18-14. – 45/50, and – 80s HPCR Spools, Stages 3-9. Not Found at AD Query, query refers to AD-2002-25-08. 08.
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91-11-05. -80A and -80C2 COMPRESSOR ROTOR, Stages 11-14. Inspect the INERTIA WELDS. Installed on, but not limited to, Airbus A300, A310 and Boeing 747 and 767s. Prior ADs - 2011-15-06 and 2002-04-11.

End

[No Fly Zone]

Rerun Due to Lost Text

I am not worried. The analysts have identified only SIX engines (Three Airplanes?) with these likely high-time engines. Five have already been inspected and number six should be completed this week, if Mr. Gates's information is correct. If I could identify the engine(s) on the next B777 that I ride, B777, would I be concerned if they turned our to be GE-90s? No.
Frankly, I'd be more interested in the carrier's Mx record, the engine's cycle count and each engine's accumulated hours to date. I cannot - do not believe that this is a systemic problem limited to to the GE-90 blow torch, as used on some early B777 airplanes. Let' avoid 'panic,' at least until some genuine cause is found. Six engines? Data Guy may - or may not - have some excellent reference points; Still a bit too soon to know. At least for now, when the FAA speaks or issues a formal AD, we must comply. For a far better understanding, I'll await the NTSB's Final Report.