Boeing 737 NG Pickle Fork issues

GM228

STB. wrote: »

Its not an AD, its an EAD. An UNSAFE condition that requires immediate action by the aircraft owner.

It's not an EAD, it's an AD.

Irish Steve

I think some perspective is needed here, this is a fast moving and dynamic issue that is evolving as checks are carried out and reported, when it first emerged, the directive required that all frames above 30K cycles were inspected urgently, and any with cracks were grounded. Lower cycle aircraft were to be inspected less urgently, and there is no inspection at present below the lower threshold. From what we can gather, and there is no obligation on operators to put this information into the public domain, there are 3 Ryanair frames affected, and the total number across the worldwide fleet of all NG operators is 5%.

I am not underestimating this situation, far from it, and I would expect that the original AD will be updated before too long to change the number of cycles at which it becomes effective, based on the findings of the examinations that are ongoing, the intention being to ensure that if cracking is starting, it is found before it has the potential to cause problems.

Many airframes of all sizes suffer cracking issues, and there is no massive outcry about safety, the important aspect being that if a crack issue is identified, it then is being monitored to ensure that it does not represent a threat to the airframe and ongoing safe operation. The Battle of Britain memorial flight Lancaster bomber has had at least 2 main spar changes over the last number of years because of cracking issues, when they were first built, the expected life of the frame was short due to the expected usage, so cracking is not a new issue, and the older members here will recall the problems that beset the Comet airliner when it was first put into service, and that resulted in a number of fatal losses before the cause was identified and corrected.

The more critical aspect is what Boeing are doing to correct the problem, either by redesign or by making other changes to avoid the issue happening, and hopefully to identify what is causing the problem in the first place, I think anyone that travels regularly on the 800 version of the NG is well aware that the landing technique is very much set a pitch angle when close to the ground, and then live with whatever happens, and if it's a very positive arrival, that's better than a tail strike caused by trying to finesse it, my fillings have rattled on a number of occasions, especially at Bristol.

The aviation industry is rightly one of the most regulated and monitored industries. In recent times, that regulation has not performed as was expected, and the result has been fatal accidents, hopefully, the lessons have been learnt, and will result in changes that will restore confidence for all concerned.

IE 222

STB. wrote: »

Do we need them to start falling out of the sky for you to understand that a key previously thought indestructible component on the bloody planes is susceptible to cracking after UNKNOWN cycles. Unless you are a psychic, you dont know the answer



There is no could about it. There are many up in Boeing getting fixed as we speak.



Its not an AD, its an EAD. An UNSAFE condition that requires immediate action by the aircraft owner.




I am clearly pointing the finger at a lack of information(even after press enquries) from the start. Get the conspiracy theory out of your head that I have it in for RyanAir.

This was reported to ALL NG operators at the end of September. Qantas were the same. The information had to be pulled out of them, with the Union representing aircraft maintenance engineers calling for them all to be grounded. Now Virgin are under pressure to test them all. Lion Air this week found cracks in two Boeing 737s below the mandatory checking threshold of 22,600 cycles.




We would not be in this position -

IF Boeing listened to the concerns of their QA staff over 10 years ago (some of which resigned and highlighted the culture within Boeing in a TV documentary),

IF the FAA has been doing independent safety checks from the start instead of abdicating that responsibility to the very manufacturers responsible for selling faulty structures to the industry.

We shouldn't be dependent on an aircraft engineer discovering it by accident when converting a passenger plane to cargo. Up til then clearly these tests were not extensive enough that they did not pick up on dangers of the unkown

And Yes your normal airline passenger does need to know that the planes are safe. If that requires specific details for the public then it should be done. Unfortunately the litany, one after the other of safety check failures will not bring people back from the dead.

What operators can do is be upfront from day 1 and say we have checked X amount and its not surprising that we are going to find some and that we immediately sent them off to be fixed.

Hardly too much to ask. After all, nobody wants to put their reputation on the line. But Boeing have already wrecked their

None have fallen out of the sky and frankly we don't know if that's what would of happened cause it hasn't happened. These cracks could of appeared 10 years ago with nothing happening. It's been spotted now and as a precaution it's been repaired.

Ryanair answered the questions fully and perfectly providing all necessary information. I really don't get what else you expect from them.

AlekSmart

Irish Steve wrote: »

I think some perspective is needed here, this is a fast moving and dynamic issue that is evolving as checks are carried out and reported, when it first emerged, the directive required that all frames above 30K cycles were inspected urgently, and any with cracks were grounded. Lower cycle aircraft were to be inspected less urgently, and there is no inspection at present below the lower threshold. From what we can gather, and there is no obligation on operators to put this information into the public domain, there are 3 Ryanair frames affected, and the total number across the worldwide fleet of all NG operators is 5%.

I am not underestimating this situation, far from it, and I would expect that the original AD will be updated before too long to change the number of cycles at which it becomes effective, based on the findings of the examinations that are ongoing, the intention being to ensure that if cracking is starting, it is found before it has the potential to cause problems.

Many airframes of all sizes suffer cracking issues, and there is no massive outcry about safety, the important aspect being that if a crack issue is identified, it then is being monitored to ensure that it does not represent a threat to the airframe and ongoing safe operation. The Battle of Britain memorial flight Lancaster bomber has had at least 2 main spar changes over the last number of years because of cracking issues, when they were first built, the expected life of the frame was short due to the expected usage, so cracking is not a new issue, and the older members here will recall the problems that beset the Comet airliner when it was first put into service, and that resulted in a number of fatal losses before the cause was identified and corrected.

The more critical aspect is what Boeing are doing to correct the problem, either by redesign or by making other changes to avoid the issue happening, and hopefully to identify what is causing the problem in the first place, I think anyone that travels regularly on the 800 version of the NG is well aware that the landing technique is very much set a pitch angle when close to the ground, and then live with whatever happens, and if it's a very positive arrival, that's better than a tail strike caused by trying to finesse it, my fillings have rattled on a number of occasions, especially at Bristol.

The aviation industry is rightly one of the most regulated and monitored industries. In recent times, that regulation has not performed as was expected, and the result has been fatal accidents, hopefully, the lessons have been learnt, and will result in changes that will restore confidence for all concerned.

The 738 landing issue has been a bugbear of mine since I first "experienced" it.
Just like IrishSteve my own fillings have rattled a bit too much,with no recompense from Ryanair.

Why exactly is Boeings recommended landing technique so "positive" ?

Is there a connection between the never ending 737 family expansion vs the reluctance to clean-sheet a design ?

My own sensation is that constant "very-positive" landings just cannot be good for the airframe itself or the many things riveted,clipped or stuck to its innards ?

billie1b

EI-DAL is fixed, will be back next week.
EI-DCL is back next week too but will stay grounded, Boeing unable to repair her at the moment.

FishOnABike

billie1b wrote: »

EI-DAL is fixed, will be back next week.
EI-DCL is back next week too but will stay grounded, Boeing unable to repair her at the moment.

Is there any explanation given why Boeing are unable to repair EI-DCL at the moment? Parts backlog, repair backlog of other aircraft for pickle fork problem or some other reason?

Irish Steve

Re the "positive landings" scenario, the following web site http://www.b737.org.uk/tailstrikes.htm may prove to be an interesting read. It's a long aircraft, and there's not much margin between the Vref (target speed for landing) and the tail strike risk speed.

Tenzor07

FishOnABike wrote: »

Is there any explanation given why Boeing are unable to repair EI-DCL at the moment? Parts backlog, repair backlog of other aircraft for pickle fork problem or some other reason?

Isn't EI-DCL the Boeing livery?

As far as I can remember it's one of the oldest if not the oldest 737 in the fleet... Maybe it's being repainted and resold on or scraped?

GM228

Tenzor07 wrote: »

Isn't EI-DCL the Boeing livery?

As far as I can remember it's one of the oldest if not the oldest 737 in the fleet... Maybe it's being repainted and resold on or scraped?

Yes it's in the Dreamliner livery, it's 15 years old so there a good few older than it, delivered October 2004.

Tenzor07

Planespotters says:

Airframe Status: Stored

GM228

The FAA has reissued an amended AD (still an AD and not an EAD), looks like the issue could be worse than originally thought:-

The FAA is superseding Airworthiness Directive (AD) 2019-20-02, which applied to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. AD 2019-20-02 required repetitive inspections for cracking of the left- and right-hand side outboard chords of frame fittings and failsafe straps at a certain station around two fasteners, and repair if any cracking is found. This AD also requires repetitive inspections for cracking of the left- and right-hand side outboard chords of frame fittings and failsafe straps at a certain station, but expands the inspection to the area around eight fasteners, and also requires repair if any cracking is found. This AD was prompted by a determination that the inspection area needs to be expanded. The FAA is issuing this AD to address the unsafe condition on these products.

Since AD 2019-20-02 was issued, the FAA has reviewed inspection findings submitted as required by paragraph (h) of AD 2019-20-02. From these findings, four airplanes have been identified to have cracking outside the initial inspection area. Based on these findings, the FAA has determined that the inspection area must be expanded from the area around two fasteners to the area around eight fasteners on both the left- and right-hand sides (which includes the area around the two fasteners inspected as required by AD 2019-20-02) to adequately address the unsafe condition

Inspection requirement now 22,600 cycles as opposed to the original 30,000:-

(1) Prior to the accumulation of 30,000 total flight cycles, or within 7 days after October 3, 2019 (the effective date of AD 2019-20-02), whichever occurs later.

(2) Prior to the accumulation of 22,600 total flight cycles, or within 1,000 flight cycles after October 3, 2019 (the effective date of AD 2019-20-02), whichever occurs later.

billie1b

EI-DAL back in today from Victorville after a stop over in KEF, going straight back into service operating the FR506

CJhaughey

Irish Steve wrote: »

Re the "positive landings" scenario, the following web site http://www.b737.org.uk/tailstrikes.htm may prove to be an interesting read. It's a long aircraft, and there's not much margin between the Vref (target speed for landing) and the tail strike risk speed.

Have a look at this pic from a -900 and see the lengths (no pun intended) that Boeing have gone to try and reduce damage from tailstrikes.

The drain tube is bent over to the right to stop it being ripped off.
The tailbumper which is the black part in front of the drain, has a little nub on the bottom of it, which should be half round, that one has a flat plane which means the bumper has contacted the ground at some point.
It does stick out more more on final with flaps out.
I think the 737 airframe has reached its maximum development anyway.

Car99

billie1b wrote: »

EI-DAL back in today from Victorville after a stop over in KEF, going straight back into service operating the FR506

Will the new Boeing hangar in LGW be used for the pickle fork rectification I wonder? Big hangar with nothing in it and its just about finished.

devnull

Tenzor07 wrote: »

Isn't EI-DCL the Boeing livery?

As far as I can remember it's one of the oldest if not the oldest 737 in the fleet... Maybe it's being repainted and resold on or scraped?

Ei-DCL went from Victorville to Reykjavik on 25th and back to Dublin yesterday.