Here is just one more example of why Airlines are more interested in profit than increased inspection intervals.[Not just SWA]
The CFM 56 Engine is the workhorse of narrow body fleets on both Boeing and Airbus Aircraft.

https://arstechnica.com/tech-p...ent-engine-failures/

https://www.cfmaeroengines.com/engines/cfm56/

Note: When Alaska Airlines FLT 261 experienced catastrophic IN FLIGHT failure of the horizontal stabilizer Jackscrew Trim an INSPECTION WAS performed VOLUNTARILY on all MD 80 type aircraft operated by 2 US Carriers. One US carrier was operating over 270 of them and still performed the inspections with AROUND THE CLOCK OVERTIME of all available manpower. This was accomplished in about 7 days and insured the airworthiness of their MD80 Fleet.

https://www.youtube.com/watch?v=Df-UGtdGryU

http://articles.latimes.com/2000/feb/10/news/mn-62922

I hate to see knee jerk reactions before the facts are known. But seems if blade fatigue was a big enough concern historically speaking, the FAA would have issued a new AMR. But with more than 30,000 CFM56's and more than 45 years of service, the engine and blades have proven themselves. There have only been a few blade failures so ordering a new AMR is going to get a lot of pushback from the industry.

But I bet the guys performing the blade inspections are going to do their job a little better. Will be interesting to see the life cycle of the blade in question.

quote:

There have only been a few blade failures so ordering a new AMR is going to get a lot of pushback from the industry.

The problem is there has been a "FEW blade failures" which indicates something different should be done concerning blade inspections.
The MD80 example took only ONE Catastrophic Horizontal Stabilizer Jackscrew Failure for the operators to do a VOLUNTARY INSPECTION of the whole fleet.

This is only ONE of the Blade Failure stories.

http://lessonslearned.faa.gov/...2&LLID=62&LLTypeID=2


"But seems if blade fatigue was a big enough concern historically speaking, the FAA would have issued a new AMR."

Crashes and in-flight fatalities due to Fan Blade Failures demands farther action.

Just heard on the evening news that an immediate inspection of 737s has been ordered.

Over-reaction or prudence?

quote:

Originally posted by Dulltool17:
Just heard on the evening news that an immediate inspection of 737s has been ordered.

Over-reaction or prudence?

Should have happened several years ago with a RECURRING AD.[Airworthiness Directive]

http://atwonline.com/engines/f...cfm56-7b-inspections

THUMBS UP! Its still a shame it took the death of a woman for this to happen.

The aircraft engine parts business is quite lucrative and competitive. I wonder if a supplier could be cutting corners on the blade manufacture. It would be interesting to know the source(s) of the failed blades.

quote:

Originally posted by 224VALMan:

quote:

There have only been a few blade failures so ordering a new AMR is going to get a lot of pushback from the industry.

The MD80 example took only ONE Catastrophic Horizontal Stabilizer Jackscrew Failure for the operators to do a VOLUNTARY INSPECTION of the whole fleet.

This is only ONE of the Blade Failure stories.

VALman:
Not to impune your observations or unknown level of your own actual Part 121 Boeing 737 (or any?) jet airline experience, however the Alaska stab jackscrew example is a straw man arguement.
The fact is that a single point failure of the Alaska stab jackscrew assembly resulted in a 100% fatal loss.....after ill advised in flight trouble shooting by the cockpit crew.
The undeniable fact of this SWA incident is that the failure of an N1 blade (the “fan”) on the #1 engine resulted in what? Oh, that’s right....a safe (admittedly newsworthy) recovery to a safe landing on the other perfectly operative engine. Something practiced in every sim session......

Suggest just cool your jets and let the regulatory agencys do their job without all the hyperventilating comment. (30,000+ CFM56 cant be wrong)

BTW: the cockpit crew (Lady Captain solely responsible if you believe the uncritical press) were just doing the job they are trained and expected to do. Hardly HERO’S.

- Mike

EDIT: apoplogize for improper terminology addressing the N1 Fan ..... corrected. I do have a couple of years experience with turbine aircraft, should have neen more precise. I was having an evening “wee Dram” when I was composing....

The SWA flight did result in a fatality due to FAN BLADE failure. The BMA crash was a result of a Fan Blade Failure so this is not a new or one off issue with the CFM 56.

http://lessonslearned.faa.gov/...2&LLID=62&LLTypeID=2

Notice how quickly the FAA and EASA issued the Blade Inspection AD after the latest incident.
It has take several failures for them to acknowledge that the FAN BLADES might just need more frequent NDT inspections.

This is why Engine blade inspection intervals are important whether its a FAN-compressor-or Turbine blade or the DISC that the blades are attached to. A failure of any of them can cause major problems.

"Redstone: Suggest just cool your jets and let the regulatory agencys do their job without all the hyperventilating comment."

He has 50 posts in two months. I'm guessing "Edmond" from Ukraine has a nephew in the states. Lots of opinions.

I'm from Tomsk Siberia. LOL!

No matter how many inspections, at some point the unexpected is going to happen. Given the number of engines in service, we're doing well.

Grizz

Minus the pax fatality we had almost the exact same thing happen on 777 going into HNL a couple of months ago.

That was on a PW 4070 engine. Blade failures happen. Of course the press is trying to lionize the Captain on the SWA flight because she was female. She made a single engine landing. Plain and simple the end.

That guy Mary Martinez is such a drama queen. The way he broadcast on FB was ridiculous. "I thought I was going to die," he said. To me it looked like he was about to start crying on his interview. Never acknowledged the woman in distress but he got his moment in the limelight.

quote:

Originally posted by Grizzly Adams:
No matter how many inspections, at some point the unexpected is going to happen. Given the number of engines in service, we're doing well.

Grizz

Note: Even frequent Inspection Intervals are not fool proof but greatly enhance the possibility of discovering a defect. Sometimes a failure reveals that a DIFFERENT TYPE of NDT Inspection is needed such as X-RAY instead of Ultrasound or Eddy Current.

The bigger question here is why the so called "Containment Ring" is not CONTAINING the blade failures?

I have a question for you guys who are pilots...

If this happened to you, would you have the First Officer visually inspect for any damage as soon as it happened? Are FAs trained to know what a normal wing config looks like? Would you ask them? I ask because AA 191 crashed as a result of loss of hydraulic fluid when its left engine separated (not that there was time for anyone to go back and see the slats on that wing retracted).

What would you guys do? I suppose if it you were not fighting an aircraft that wanted to roll and your cockpit indications didn't indicate anything unusual other than the loss of the engine, you might feel two in the front was better than a quick check, but just curious.

quote:

No matter how many inspections, at some point the unexpected is going to happen. Given the number of engines in service, we're doing well.

So, we shouldn't bother doing inspections? It seems to me that we learn with each incident. That information is then analyzed and intelligent people ask :what can we do proactively to avoid this happening again?
Makes sense to me!
Peter

quote:

Originally posted by AnotherAZWriter:
I have a question for you guys who are pilots...

If this happened to you, would you have the First Officer visually inspect for any damage as soon as it happened? Are FAs trained to know what a normal wing config looks like? Would you ask them? I ask because AA 191 crashed as a result of loss of hydraulic fluid when its left engine separated (not that there was time for anyone to go back and see the slats on that wing retracted).

What would you guys do? I suppose if it you were not fighting an aircraft that wanted to roll and your cockpit indications didn't indicate anything unusual other than the loss of the engine, you might feel two in the front was better than a quick check, but just curious.

It just depends on the situation. But in this case they were dealing with, an engine fire, engine failure, explosive decompression, a rapid descent, a diversion and a medical emergency. As long as they didn’t have any control issues or hydraulic loss indications sending someone back would have been futile as they were knee deep in alligators up front.

The 737 will let you know if she’s bleeding off hydraulic fluid and is completely controllable with loss of hydraulics. AA 191 was a DC 10 which had no hydraulic check valves or mechanical down locks on the flaps which is what caused the flaps to retract on the damaged wing. A 737 won’t do that.

quote:

Originally posted by surestrike:

quote:

Originally posted by AnotherAZWriter:
I have a question for you guys who are pilots...

If this happened to you, would you have the First Officer visually inspect for any damage as soon as it happened? Are FAs trained to know what a normal wing config looks like? Would you ask them? I ask because AA 191 crashed as a result of loss of hydraulic fluid when its left engine separated (not that there was time for anyone to go back and see the slats on that wing retracted).

What would you guys do? I suppose if it you were not fighting an aircraft that wanted to roll and your cockpit indications didn't indicate anything unusual other than the loss of the engine, you might feel two in the front was better than a quick check, but just curious.

It just depends on the situation. But in this case they were dealing with, an engine fire, engine failure, explosive decompression, a rapid descent, a diversion and a medical emergency. As long as they didn’t have any control issues or hydraulic loss indications sending someone back would have been futile as they were knee deep in alligators up front.

The 737 will let you know if she’s bleeding off hydraulic fluid and is completely controllable with loss of hydraulics. AA 191 was a DC 10 which had no hydraulic check valves or mechanical down locks on the flaps which is what caused the flaps to retract on the damaged wing. A 737 won’t do that.

Thanks for that answer.

quote:

Originally posted by Redstone:

quote:

Originally posted by 224VALMan:

quote:

There have only been a few blade failures so ordering a new AMR is going to get a lot of pushback from the industry.

The MD80 example took only ONE Catastrophic Horizontal Stabilizer Jackscrew Failure for the operators to do a VOLUNTARY INSPECTION of the whole fleet.

This is only ONE of the Blade Failure stories.

VALman:
Not to impune your observations or unknown level of your own actual Part 121 Boeing 737 (or any?) jet airline experience, however the Alaska stab jackscrew example is a straw man arguement.
The fact is that a single point failure of the Alaska stab jackscrew assembly resulted in a 100% fatal loss.....after ill advised in flight trouble shooting by the cockpit crew.
The undeniable fact of this SWA incident is that the failure of an N1 blade (the “fan”) on the #1 engine resulted in what? Oh, that’s right....a safe (admittedly newsworthy) recovery to a safe landing on the other perfectly operative engine. Something practiced in every sim session......

Suggest just cool your jets and let the regulatory agencys do their job without all the hyperventilating comment. (30,000+ CFM56 cant be wrong)

BTW: the cockpit crew (Lady Captain solely responsible if you believe the uncritical press) were just doing the job they are trained and expected to do. Hardly HERO’S.

- Mike

EDIT: apoplogize for improper terminology addressing the N1 Fan ..... corrected. I do have a couple of years experience with turbine aircraft, should have neen more precise. I was having an evening “wee Dram” when I was composing....

Not trying to be pedantic or anything, but technically speaking the blade involved belonged to the C1 fan, making it a C1 fan blade, not an “N1” fan blade. All the blades on the low speed/low pressure spool are actually “N1” blades. “C1” refers to the first compressor, which can be seen from the front of the engine. The “C2”, “C3””, etc, are the successive compressor stages behind the C1, which make up the low speed/low pressure compressor section. The speed of the low pressure/low speed spool is displayed in the cockpit as the “N1”speed, which can be a bit confusing.

I’ve worked for SWA for the last 18 Year’s, and can say the “New Southwest” bears little resemblance to the “Old Southwest” of “Herb and Colleen” fame. Profit matters. Aircraft parts that are removed for repair or overhaul generally have individual serial numbers, allowing them to be tracked as to time in service and location. About 8 years ago, SWA stopped regarding C1 blades as “rotable” parts, and stopped tracking them for whatever reason ($$$?). When the FAA required inspection of certain C1 blades, the company had no idea of which engines they were installed in, or if the company even owned the blade in question. This meant that every blade, whether on the list or not, had to be inspected. All 35,000 plus of ‘em, which threw a lot of extra work on the techs and inspectors, which meant that minimums became the rule rather than the exception. Rumor about the shop is that the failed blade had signs of dye penetrant in the crack.

This concludes the engineering lesson for this evening.

Porosonik.

Not sure which is more troubling - the fact that they are not able to track the lifespan of blades or the possibility the failed blade had dye penetrant in the crack.

As a rule, dye-pen inspection is not as certain as eddy current or other types of NDT. Again shop rumor, but the inspector who did the dye-pen inspection on the blade in question wanted to do an eddy current inspection, but was declined because it would take an extra 15 minutes.

The world of aviation maintenance has changed a lot in the 32 years I’ve been doing it....

Porosonik.