787 engine failure in Charleston, SC
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From: Dallas, TX USA
787 engine failure in Charleston, SC
Surprised this hasn't been posted yet.
Boeing 787 Engine Failure Sparks Fire at Charleston Airport | Aviation International News
"Another Boeing 787 engine problem—this time involving a General Electric GEnx turbofan in an airplane destined for Air India—sparked a grass fire at Charleston International Airport during a pre-flight test on Saturday, forcing the airport to close its main runway for more than an hour. The contained engine failure has prompted an investigation by the NTSB, Boeing and GE, maker of the engine now in service with Japan Airlines on four 787s."
Boeing 787 Engine Failure Sparks Fire at Charleston Airport | Aviation International News
"Another Boeing 787 engine problem—this time involving a General Electric GEnx turbofan in an airplane destined for Air India—sparked a grass fire at Charleston International Airport during a pre-flight test on Saturday, forcing the airport to close its main runway for more than an hour. The contained engine failure has prompted an investigation by the NTSB, Boeing and GE, maker of the engine now in service with Japan Airlines on four 787s."
Usual disclaimers apply!
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From: EGGW
Engine shaft sheared allowing the complete LPT assy to move aft.......and out
.
IIRC sheared at the end of the thread where the coupling nut is!
Same thing happened to a 744 with CF6-80's recently too......must be a GE thing.
And the AC 773 GE90-115 was a failure in the HPT section...hence the bang!
That was an HPT stage one shroud departing company taking everything aft with it!
.IIRC sheared at the end of the thread where the coupling nut is!
Same thing happened to a 744 with CF6-80's recently too......must be a GE thing.
And the AC 773 GE90-115 was a failure in the HPT section...hence the bang!
That was an HPT stage one shroud departing company taking everything aft with it!
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From: California
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From: Blighty
I suppose the usual suspects will appear on pprune soon enough demanding that the entire fleet be grounded due to Rolls Royce being unable to design a reliable engine...........oh wait, this is an American GE engine. No problem. 
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From: Here
Not an engineer... Sorry for the intrusion
NTSB Urgent Recommendation to FAA : Inspect GEnx Fan Mid Shafts Immediately .
See aviation week :
http://www.aviationweek.com/Blogs.as...c-6bb1d09569bc
And :
http://www.ntsb.gov/doclib/recletter...12-052-053.pdf
Highlights :
- The first failure (GEnx-1B) at Charleston was caused by a fractured forward end of the Fan Mid shaft (FMS), that separated at the rear of the threads.
- The fracture was no fatigue cracking.
- Further examination revealed a faceted, quasi-cleavage fracture morphology that is typical of environmentally assisted cracking of certain high strength steel alloys such as that used on the GEnx FMS.
- A second (zero flight hour) GEnx-1B FMS with a fracture was found during engine checks.
- The investigation into the cause of the environmentally assisted cracking that occurred at both fractured FMSs is continuing.
- The damage noted on the photographs of the GEnx-2B (Shanghai) is consistent with that observed on the engine that failed at Charleston.
- The GEnx-1B FMS is slightly longer than that in the -2B engine. However, the threaded end of the FMS; the manner in which it is clamped with the retaining nut and the assembly procedures, material specifications, and operating environment are similar between the two models. Therefore, the FMS in GEnx-2B engines may be susceptible to the same type of failure observed with the GEnX-1B FMS.
- the NTSB recommends that the FAA require operators to accomplish repetitive inspections of the FMS in all (on-wing and spare) GE GEnx-1B and -2B engines at a sufficiently short interval that would permit multiple inspections and the detection of a crack before it could reach critical length and the FMS.
See aviation week :
http://www.aviationweek.com/Blogs.as...c-6bb1d09569bc
And :
http://www.ntsb.gov/doclib/recletter...12-052-053.pdf
Highlights :
- The first failure (GEnx-1B) at Charleston was caused by a fractured forward end of the Fan Mid shaft (FMS), that separated at the rear of the threads.
- The fracture was no fatigue cracking.
- Further examination revealed a faceted, quasi-cleavage fracture morphology that is typical of environmentally assisted cracking of certain high strength steel alloys such as that used on the GEnx FMS.
- A second (zero flight hour) GEnx-1B FMS with a fracture was found during engine checks.
- The investigation into the cause of the environmentally assisted cracking that occurred at both fractured FMSs is continuing.
- The damage noted on the photographs of the GEnx-2B (Shanghai) is consistent with that observed on the engine that failed at Charleston.
- The GEnx-1B FMS is slightly longer than that in the -2B engine. However, the threaded end of the FMS; the manner in which it is clamped with the retaining nut and the assembly procedures, material specifications, and operating environment are similar between the two models. Therefore, the FMS in GEnx-2B engines may be susceptible to the same type of failure observed with the GEnX-1B FMS.
- the NTSB recommends that the FAA require operators to accomplish repetitive inspections of the FMS in all (on-wing and spare) GE GEnx-1B and -2B engines at a sufficiently short interval that would permit multiple inspections and the detection of a crack before it could reach critical length and the FMS.
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From: Texas
Repetitive inspections of spare engines? Let me get this straight, you inspect what is a brand new engine and after a period of time you have to reinspect it because it may have developed a serious structural fault sitting in an engine stand? I wonder how GE is going to make this up to their customers.
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From: Florida
Repetitive inspections of spare engines? Let me get this straight, you inspect what is a brand new engine and after a period of time you have to reinspect it because it may have developed a serious structural fault sitting in an engine stand? I wonder how GE is going to make this up to their customers.
In other words business as usual (on the business side).
I believe that RR went through something similar a couple of years back as did P&W.
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From: Grassy Valley
MarkerInbound,
." Because of the immediate threat of multiple engine failures on a single aircraft and the availability of an appropriate inspection procedure, there is an urgent need for the FAA to act immediately."
NTSB...
The threat would appear that the crack can progress without load, withut even being on wing. It is "environmental" in nature, the report claims that the steel used in this Fan shaft is susceptible to atmospheric Hydrogen causing an accelerated galvanic corrosive propagation of cracking. They also are cautious that ETOPS is affected, should the shaft fail, and the remaining engine may be subject to 5.5 hours of operation OEI.
This would appear on the face of it to be at least as problematic as the RR TRENT problem with spline wear at the shaft efface.
The link is instructive... and direct, no soft pedalling, as it should be.
regards
." Because of the immediate threat of multiple engine failures on a single aircraft and the availability of an appropriate inspection procedure, there is an urgent need for the FAA to act immediately."
NTSB...
The threat would appear that the crack can progress without load, withut even being on wing. It is "environmental" in nature, the report claims that the steel used in this Fan shaft is susceptible to atmospheric Hydrogen causing an accelerated galvanic corrosive propagation of cracking. They also are cautious that ETOPS is affected, should the shaft fail, and the remaining engine may be subject to 5.5 hours of operation OEI.
This would appear on the face of it to be at least as problematic as the RR TRENT problem with spline wear at the shaft efface.
The link is instructive... and direct, no soft pedalling, as it should be.
regards
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From: Alaska
[quote
The threat would appear that the crack can progress without load, withut even being on wing. It is "environmental" in nature, the report claims that the steel used in this Fan shaft is susceptible to atmospheric Hydrogen causing an accelerated galvanic corrosive propagation of cracking.][/quote]
Is GE building engines out of chinese pot metal these days? How could the engineers possibly have missed this?
The threat would appear that the crack can progress without load, withut even being on wing. It is "environmental" in nature, the report claims that the steel used in this Fan shaft is susceptible to atmospheric Hydrogen causing an accelerated galvanic corrosive propagation of cracking.][/quote]
Is GE building engines out of chinese pot metal these days? How could the engineers possibly have missed this?
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From: Florida
Is GE building engines out of chinese pot metal these days? How could the engineers possibly have missed this?
I suspect that there are quite a few other examples in the literature.
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From: Grassy Valley
"While none of the parties involved are able to confirm this, a statement from GE that it has introduced an “improved coating process to the mid-shaft of new-production GEnx engines” would appear to define this as the most likely cause."
Near new, and yet to be mounted engines are in failure? Not Stress, or fatique?
lomapaseo, can you provide several examples of this in the literature?
Since threads are not ordinarily "coated" but need to efface each other clean,
the fix appears to be impossible as described. Perhaps the nut and threads are encapsulated with an applied coating. Not familiar.
Near new, and yet to be mounted engines are in failure? Not Stress, or fatique?
lomapaseo, can you provide several examples of this in the literature?
Since threads are not ordinarily "coated" but need to efface each other clean,
the fix appears to be impossible as described. Perhaps the nut and threads are encapsulated with an applied coating. Not familiar.
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From: Texas
Lomapaseo,
That's what I was implying, if airlines have to ground their brand new planes, GE is going to have to throw tons of money at them to keep the airlines happy. Not good for their bottom line.
Lyman,
I understand the urgency, I've made three legs in a -8. I'm just amazed that GE could create and have certified an engine with such issues.
That's what I was implying, if airlines have to ground their brand new planes, GE is going to have to throw tons of money at them to keep the airlines happy. Not good for their bottom line.
Lyman,
I understand the urgency, I've made three legs in a -8. I'm just amazed that GE could create and have certified an engine with such issues.
Last edited by MarkerInbound; 18th September 2012 at 03:12.
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From: Not far from a big Lake
Hydrogen embrittlement seems a likely candidate given the described failure mode.
Here is the Wiki on that: Hydrogen embrittlement - Wikipedia, the free encyclopedia
I can remember some large spacer washers on the McDonnell F-4 that kept the stabilator centered on the fuselage. These things were way overdesigned to look at them, but they were failing in service because they didn't have the hydrogen driven out of the metal following plating operations. (Improper process specification) You could tell when one failed because the stabilator would then scar the side of the fuselage as it moved. Those massive washers behaved as if they were made of glass!
Here is the Wiki on that: Hydrogen embrittlement - Wikipedia, the free encyclopedia
I can remember some large spacer washers on the McDonnell F-4 that kept the stabilator centered on the fuselage. These things were way overdesigned to look at them, but they were failing in service because they didn't have the hydrogen driven out of the metal following plating operations. (Improper process specification) You could tell when one failed because the stabilator would then scar the side of the fuselage as it moved. Those massive washers behaved as if they were made of glass!
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From: Grassy Valley
Hi
From NTSB....
"On July 28, 2012, a Boeing 787-8 airplane experienced a loss of thrust in the right engine—a General Electric (GE) GEnx-1B turbofan, engine serial number (ESN) 956-121—"
First I've seen that id, but whatcha gonna do?
From NTSB....
"On July 28, 2012, a Boeing 787-8 airplane experienced a loss of thrust in the right engine—a General Electric (GE) GEnx-1B turbofan, engine serial number (ESN) 956-121—"
First I've seen that id, but whatcha gonna do?