Debris Found in Undelivered 737MAx FUEL TANKS
 

737 Max: Debris found in planes' fuel tanks

The head of Boeing's 737 programme has told employees that the discovery was "absolutely unacceptable".

A Boeing spokesman said the company did not see the issue further delaying the jet's return to service.

It comes as the 737 Max remains grounded after two fatal crashes.

The US plane maker said it discovered so-called "Foreign Object Debris" left inside the wing fuel tanks of several undelivered 737 Maxs.

A company spokesman told the BBC: "While conducting maintenance we discovered Foreign Object Debris (FOD) in undelivered 737 Max airplanes currently in storage. That finding led to a robust internal investigation and immediate corrective actions in our production system."

Foreign Object Debris is an industrial term for rags, tools, metal shavings and other materials left behind by workers during the assembly process.

• No timescale for 737 Max return, US regulator says
• Boeing reports its first loss in two decades
• Boeing delays 737 Max return date to July

The revelation is the latest in a string of problems affecting what was once Boeing's best-selling plane.

The aircraft has been grounded by regulators around the world since March 2019.

It was banned from flying after two separate crashes killed 346 people.

737 Max timeline

• 29 October 2018: A 737 Max 8 operated by Lion Air crashes after leaving Indonesia, killing all 189 people on board
• 31 January 2019: Boeing reports an order of 5,011 Max planes from 79 customers
• 10 March 2019: A 737 Max 8 operated by Ethiopian Airlines crashes, killing all 157 people on board
• 14 March 2019: Boeing grounds entire 737 Max aircraft fleet

The US regulator, the Federal Aviation Administration (FAA), told the BBC that it was monitoring the plane maker's response to the new issue: "The FAA is aware that Boeing is conducting a voluntary inspection of undelivered aircraft for Foreign Object Debris (FOD) as part of the company's ongoing efforts to ensure manufacturing quality.

"The agency increased its surveillance based on initial inspection reports and will take further action based on the findings," it added.

Boeing said it didn't expect the issue to cause any fresh delays to the 737 Max's return to service, which the company said could happen by the middle of this year.

I’m not convinced that this issue would be limited to just the 737 Max production lines. Checks should cover all Boeing aircraft imho.

Not the first time
 

I remember working in A/C major overhaul hanger and a customer found a bucking bar used for riveting in a fuel tank,here's the funny part the company told us to stamp our name on all our tools,do you think anyone did that.

All newly built aircraft will have a certain amount of debris left behind at construction even after careful cleaning.
When I was being trained back in the 1960's we were told of a case where a loud clonking noise was heard while the integral fuel tanks in a wing were being 'shoshed' with liquid coating.
On investigation a vacuum cleaner was found, having been overlooked when the final skin was riveted in place.
FOD doesn't get much bigger than that!

I beg to differ.

The 'absolutely unacceptable' comment did make me smile - that FOD was present, or that someone spotted it? :}

Nothing new for Boeing
 

...
Nothing new for Boeing unfortunately. The problem has migrated from the KC-46. These from a year ago -

https://www.seattletimes.com/busines...manufacturing/

See page 46 - post 906 by ORAC - https://www.pprune.org/military-avia...a-woes-46.html

...

An instructor at Oxford about 13 years ago claimed he was once tasked with investigating a fuel issue (random engine cutout) and found a large piece of carpet inside the wing of a mil jet transport plane.

Lordflasheart

10691149]..

Actually, it's something that has been going on for a lot longer than the above type.

The initial deliveries of the 767 resulted in a lot of fuel pump failures until the problem was traced to swarf in the fuel tanks notably the centre tank. The Boeing reps we worked with at the time, both a credit to Boeing and themselves, really nice people and very professional engineers, were " somewhat scathing " as to the calibre of those recently hired to build the aircraft.

To be fair, Boeing subsequently imposed a far more intensive QC and inspection regime after which, no more fuel pump failures,

Boeing managment should be fired. All of them. And then put on trial. Volkswagen was forced to pay billions of $ becaues of the dieselgate, and Boeing still dodges any kind of formal punishment.

Sounds more versatile than an issued kneepad. Though unfortuneately not strapped to the owner.

Same to Airbus
 

They should fire the ones who paid airlines to buy their junk.

Yes it does: when I was working on Vulcans many years ago, there was a story that a wooden chair had been found inside a Vulcan wing fuel tank once!

What is funny about that?

It should be impossible for a tool to be left behind. The usual process at the end of a shift change is to make sure that every fitter accounts for every one of their tools. If something is missing, the whole shift has to stay and look for it, and they won't be too thrilled. That's a pretty big incentive to diligently account for all your tools!

That should be the culture when working on aircraft.

Thank you possel! I remembered reading that story but had forgotten the details. Made me smile!

It wasn't funny
 

I did not mean it to be funny,the company should have had produced safeguards

The military have something called "tool control". It could refer to people, although I've always assumed it referred to spanners etc.

threes

Just as in the med/surgical world: none of us would take too kindly for the scalpel to be left inside after the op. In the past, the medical world has benefited from aviation's practice of confidential reporting. Time for the aviation world to learn from the medical one. Given the potential seriousness of the most minor error, one wonders that any management who didn't enforce accountability of tools, and thorough disposal of FOD, should be able to stay in post. A raft of senior sackings would perhaps go a long way to sorting the problem.

Not at all clear that the world of surgery has this issue locked down. Wikipedia (I know, I know) reports that

One could argue though that human bowels are slightly more cluttered than your average aluminum cavitiy in aviation. Maybe we do also have some surgeons on the forum who can comment ;).

Before we all over-fulminate about the debris being found, let's all remember that it was found, and moreover it was found in the course of an inspection made specifically to ensure that any debris would be found.

Having found it, it would be equally a matter of good routine and practice to report it with a view to pre-delivery prevention of debris in fuel tanks in the future. (Boeing MEDA process, for those who know, as copied throughout the industry).

The inspection was/is a capture point designed to make sure that no debris is present, and as such it worked perfectly.

End of story. A more sensational story would have been "Debris not found in B737 fuel tanks before delivery".

Boring, eh?

The again the size of the FOD relative to the cavity...

Keeping the tanks clean from the factory is not enough.
Humorous anecdote - an airplane was being refueled. Got all done and time to unlatch the hose. The handle on the hose shut-off valve would not return to the shut-off position. Because of a mechanical interlock to keep the fuel from pouring out of the hose when it was not coupled to a supply tank or an aircraft, the hose could not be uncoupled without first closing the valve, which could not be done.

Break out the metal cutting saw to slice through the valve, but not before the panicked ground crew tried to pry the hose end from the aircraft, damaging the aircraft severely.

For some reason, known to no one, a meter stick had made its way into that valve when it had been opened, blocking the valve from closing again. Apparently, at some time, the meter stick had been stowed into the hose.

So, on the contract I was working, the requirement was to use fuel connectors that had integral fuel strainers.

old,not bold

Do you have any more details on that? I've only found mention of "during maintenance".

PS
From: https://www.flightglobal.com/air-tra...136819.article

Boeing has ordered the inspection of all undelivered 737 Maxes, after it found debris in the wing fuel tanks of some of the grounded narrowbodies.

The airframer states that it has also recommended 737 Max customers globally with aircraft in active storage for more than a year to inspect the fuel tank for foreign object debris (FOD).

The company states it first discovered FOD while conducting maintenance on undelivered 737 Maxes in storage at its Renton facility.

That finding led to a robust internal investigation and immediate corrective actions in our production system. We are also inspecting all stored 737 Max airplanes at Boeing to ensure there is no FOD,” the airframer states.

That isn't giving me a warm feeling that the FOD was found by a regular check made on all planes as part of pre-delivery.
I would like to be reassured.

On an early 747s first major overhaul, I found nice large chrome Crow bar in the air conditioning bay.
Some things dont change.

threep

... or a pretty big disincentive to account for all tools so everyone can go home and feed the cat.

A number of large black birds drinking beer in a gaudy dive somewhere in the belly then?
Did you report a birdstrike?

My wife's former job was civilian US Army helicopter support. One ongoing problem was that tools went missing all the time. To ensure the right tools were used, they were supplied to the mechanics, who had lessened motive to keep track of them. There were repeated efforts to make tool-box inserts with individual recesses for the tools so an inventory at a glance could be done, but it always worked out that there was too much variety and therefore too much cost to manufacture them. So they tried to find a pour-in liquid that would either cool or cure. The best one was a promising proposal that went really well into a number of presentations, until the supplier mentioned that the fumes produced during the process were highly toxic. Yup - no one was going to ship this to thousands of Army mechanics to apply on their own.

The main loss of tools seemed to be simple theft, but you cannot necessarily be sure the mechanic missing the tool is the one stealing the tool.

As a side note, when moving helicopters by ship, they would frequently arrive with various knobs missing from control panels. The initial user claim was that shipping vibration was responsible, but they did some cases with full stretch wrap of the entire helicopter. I guess plastic wrap magically damped those high levels of vibration on the ships because the knobs of those helicopters arrived in place and secure. Sigh.

Visited the shop floor of a well-known producer of engine nacelles not long ago, at their final assembly plant where the nacelles are installed on the engines. They had some rather fancy tool cabinets with internal scanners, which meant the assembly workers had to use their electronic badge to "scan out" every single piece of tool they used. When they closed the cabinets up, it would scan the contents and in case a tool was missing, would sound an alarm advising exactly which tool was missing. Until it was located and put back in its correct place, the employee would be unable to badge out from work. They never had a tool go missing after introducing these cabinets.

There is also this report from April 2019 of debris from fastening swarf up to the size of work lights and ladders being left in 787s made in Charleston:
https://www.nytimes.com/2019/04/20/b...-problems.html

This story also says the FAA were not very active in resolving the problems.

Early 70's on Jaguar flight test one prototype had recurring issues with low fuel pressure and collector box warnings, Eventually traced to a packet of safety matches stuck in pump intake. Centre fuselage was a French section and they were French matches. Quality overall was very good though.

This is nothing new with the B737, l can recall finding Fod outside of the fuel tanks on the B737-200 series of the B737.

When I was at Bruggen in the RAF a Jaguar on a post maintenance test flight went inverted and a 6" 3/8 drive socket extension floated in front of the pilots face.

Yes, well, it's a point of view; but we can be fairly certain that a mechanic checked the tanks because that task was on a worksheet given to him or her. In other words it was a pre-planned systemic check; whether it was technically "maintenance" is a matter of semantics. The aircraft are in storage, if I understood it correctly, and there will be a maintenance regime in force for that storage, plus another set of tasks to prepare for removal from storage into service. Somewhere in either or both of those regimes there will be a visual internal inspection of fuel tanks. I see that as a capture of something that has gone wrong, which should be reported and put right once the root cause has been established. The important point is that the capture did its job.

We could speculate that two things actually went wrong, and that each one needs its root cause analysis; firstly the debris should never have got into the tank, and secondly I would have thought that as the aircraft left the factory into storage the debris should have been looked for and found in the course of a final quality inspection. After all, in other circumstances it might have gone to a customer and not into storage. To that extent I share your misgivings.

Boeing is probably ahead of us all; see #1 above; "That finding led to a robust internal investigation and immediate corrective actions in our production system." I'd like to think they used the MEDA template, since they've given it to the world, but who knows.

Concorde fuel tanks

I wonder what happened to all that Kevlar that they put in to Concorde fuel tanks after the Paris crash??

At the time, there was a great video of the fitting, but I can't find it now.

Yep that "Team, ... FOD is absolutely unacceptable ... (no greets) Mark" letter sounded like good kick in the crotch, the stand downs mentioned were for sure fun and more check lists and signage will certainly improve shop floor morale to be more forward looking and proactive.

old,not bold

Thanks for the reassurance. The term "during maintenance" sparked thoughts of FOD found on a fuel filter triggering a fuller inspection of the tanks.

I recall a certain number of small items being found in the fuel tanks of BA38 the T7 which crashed at LHR in 2008.

Although these were not deemed to have attributed to the cause of the crash, it's certainly an undesirable situation, regardless of whether they were there from delivery or introduced at a subsequent time.

From page 5 of the Final Report