FAA issues 'emergency' order for airlines to inspect fan blades on engine type that exploded

[brooklynite]

Source: CNBC

The U.S. airline regulator on Friday ordered airlines to inspect the fan blades of some engines of the same type that exploded on a Southwest Airlines flight earlier this week. One passenger was killed when one of the Boeing 737's engine's fan blades broke loose.

The Federal Aviation Administration (FAA) issued an Emergency Airworthiness Directive (EAD) that requires operators to inspect fan blades on certain CFM56-7B engines within 20 days. The directive is based on a CFM International Service Bulletin issued today and on information gathered from the investigation of Tuesday's Southwest Airlines engine failure. The inspection requirement applies to CFM56-7B engines. Specifically, engines with more than 30,000 total cycles from new must undergo inspections within 20 days. The EAD becomes effective upon publication. The engine manufacturer estimates today's corrective action affects 352 engines in the U.S. and 681 engines worldwide.

This story is developing. Please check back for updates.

Read more: https://www.cnbc.com/2018/04/20/faa-issues-emergency-order-for-airlines-to-inspect-fan-blades-on-engine-type-that-exploded-on-southwest-flight.html

[still_one]

1. I am glad they are acting on this quickly

[jameslandy]

2. deregulation

So the airlines have to ground aircraft and spend money to inspect engines. When is the trumpster going to eliminate this costly government overreach regulation?

[elleng]

3. SAFETY regulation? Never, one hopes.

'Economic' regulation, for instance re: mergers,' is another thing.

[paleotn]

4. But, but, but.....

The free market! Sure, a few may have to die in the process, but the free market will sort all this out. Hey, you've got a break a few eggs to make an omelet

[GulfCoast66]

9. Air travel has gotten much safer since deregulation

Airline travel has never been as safe as it is today. Regulation was not about safety but market regulation.

And not only is air travel much safer it is so much more affordable.

[elleng]

12. You are confusing the issues of economic regulation and safety,

and you state conclusions without facts.

[GulfCoast66]

13. I stated 2 facts:

1. Air travel is safer now than ever before.

2. Air travel is more affordable than before deregulation.

Both of those are facts.

Deregulation has little to do with fact No. 1 since airline deregulation had nothing to do with safety regulations. Competition and mainly technology advances account for that.

Deregulation had everything to do with fact number 2.

[elleng]

15. You stated conclusions.

[GulfCoast66]

16. Both of the things I stated are facts

Air travel is safer than ever.

Air travel is cheaper than before deregulation.


I am shocked at how many people on DU defend air travel before deregulation. It was certainly plush but the average person could not afford to fly very much.

I have stated several facts that support deregulation. Facts. Not conclusions whatever that was supposed to mean.

How about you step up and tell us the advantages we would have if we re-regulated the Airlines.

[DeminPennswoods]

5. This isn't about deregulation

Last edited Fri Apr 20, 2018, 08:08 PM - Edit history (1)

There's a long history of jet engine components like blades, vanes and disks failing. AFAIK, there's never been an algorithm developed that would/can predict when a failure will occur or what exact operating paramenters lead to failures. Sometimes these components pass inspection, then fail. It's known as "zero propagation" or the component shows no cracks or abnormalities before failing. IOW, the component gives no sign it's ready to fail. I'm not surpised the FAA and/or GE has slapped an hour limit on the fan blades; that's the usual course of action.

FTR, this is exactly the same thing the military services do when there's a component failure. They put on a hour limit, then inspect and replace as needed. They do not replace all the fan blade sets if one blade fails. It's cost prohibative and imho the few blade manufacturers and the manufacturers of the forgings and castings from which these components are made would not have the capacity to produce enough new parts to meet the demand of 100% replacement.

ETA: Reading further, it appears the blade did show cracks. It's absolutely inexcusable for Southwest to have not replaced the blade set. If I'm the family of the passenger who died, I'd be getting the best personal injury lawyer I could find and suing Southwest for all they're worth. I realize sometimes the engineers do allow components to continue in service with some degree of cracking, but blade sets are not so expensive that replacing one pair puts a big dent in profits.

[James48]

7. Cracks

That blade DID show evidence of a pre-existing crack, but I have not seen anything that says Southwest saw it before this accident. The NTSB’s statement was that the post-accident inspection showed that that blade had evidence of a crack propagating for a while. Typically that means avdiscoloration of the metal surface in the crack, followed by the clean break edge of the final catastrophic failure.

It will take some time to sort out- it is very, very early in this investigation.

[DeminPennswoods]

17. There should be a service bulletin

on the blade cracking from the OEM. This wasn't the first incident of blade failure on this particular engine. I know from experience that sometimes the engineers allow components to continue in service with some degree of cracking, but without seeing the maintenance bulletin, assuming there is one, who knows?

The FAA did have a requirement out that all airlines with aircraft equipped with this particular CFM56 engine model inspect the fan blades, but the airlines pushed back against the time (12 months) the FAA gave them to comply. Southwest got really lucky. When I worked at DoD, I recall an F14 crash from a similar blade failure.

[Bernardo de La Paz]

18. Hello: Regulation mandates more frequent inspections & repair when problems found. It is about regs.

[DeminPennswoods]

19. The FAA had an order out to inspect the blades

before the accident happened.

[barbtries]

6. okay i'm flying across the country Sunday

on a 737-800 - is it a different plane? thank you

it's not going to keep me off the plane so i don't even know why i'm wasting energy stressing it at all.

[bluecollar2]

8. Different plane

And different engine

[barbtries]

10. thank you

i tried to google it but still wasn't sure after that. i knew someone on DU would know!

[bluecollar2]

11. I should clarify

The -800 Is a next generation airframe. The engine is actually the same model number but will probably have significantly lower hours/cycles on it.

In any event, I wouldn't concern myself too much.

I was a mechanic for over 31 years and specialized in airframe maintenance and spent 10 years in the engine overhaul shop doing non-destructive testing on jet engine components.

Given the number of engines in service world-wide and the number of blades spinning at high speeds for hours at a time, and the reliability of the engine I would suspect that the failure of the blade on this engine will eventually be traced to a human factor rather than an engineering design issue or a manufacturing defect.

Enjoy your flight!

[barbtries]

14. thanks

i have a good book to read and tend to sleep well on the plane. enjoy, not so much, but yeah. thank you for sharing your expertise.

[LastLiberal in PalmSprings]

20. I just finished checking my fan's blades.

I think they're good for another couple of years.