Boeing Faces Fine From FAA After Installing Faulty 737 Parts

Yesterday brought yet more bad news for Boeing as it received a multi-million-dollar fine from the Federal Aviation Administration. The FAA has accused Boeing of knowingly installing faulty parts on around 133 Boeing 737s in 2018 and 2019.

Boeing 737-924(w) ‘N39461’ United Airlines
The faulty components were installed on Boeing 737 NG and Boeing 737 MAX types. Photo: Alan Wilson via Flickr

2019 is drawing to a close, but the year continues to torment Boeing with more accusations of faulty components and failings in the company’s quality assurance processes. The FAA published a press release yesterday, outlining the details of its claims against Boeing.

Faulty slat tracks

According to the FAA, Boeing installed faulty slat tracks, which are part of the slat mechanism on the leading edge of the aircraft’s wings, on numerous Boeing 737s. In total, approximately 133 Boeing 737s were installed with the faulty components across a period stretching between 2018 and 2019.


According to the FAA, the faulty slat tracks were affected by an issue known as ‘hydrogen embrittlement’, which can occur during the cadmium-titanium plating process. As a result of this hydrogen embrittlement, the slat tracks should not have been approved for use.

Boeing 737 NG wing
Slat tracks guide the slats on the leading edge of an aircraft’s wing. Photo: Altair78 via Wikimedia Commons

The faulty slat tracks were processed by one of Boeing’s third-party suppliers, Southwest United Industries, which carried out the cadmium-titanium plating. Southwest United Industries then delivered the plated slat tracks to Spirit AeroSystems, which then supplied them to Boeing.

Southwest United Industries detected the hydrogen embrittlement in the batch of slat tracks, informing the manufacturer of the components, Kencoa Aerospace. Kencoa Aerospace then informed Spirit AeroSystems about the embrittlement. Boeing was then in turn informed of the issue by Spirit AeroSystems in September 2018.


The FAA did not become aware of the slat track issues until much later. Once it did, it issued an Airworthiness Directive which came into effect on 10 June 2019.

Where did Boeing go wrong?

Despite being made aware of the hydrogen embrittlement which was detected in the batch of slat tracks, Boeing continued to install them on Boeing 737 MAX and Boeing 737 NG models.

The FAA also claims that during the period between 10 October 2018 and 2 May 2019, Boeing knowingly certified 85 aircraft which had potentially been fitted with slat tracks from the faulty batch.

The slat track issue was further complicated by the fact that Southwest United Industries failed to apply a protective coating over the identification numbers on the slat tracks themselves. This meant that it was hard to identify which slat tracks had been affected.

Although the hydrogen embrittlement was not a result of manufacturing errors on Boeing’s part, the FAA alleges that Boeing failed in its duty to properly oversee the quality assurance processes of its suppliers.

Boeing 737 MAX
The slat tracks were affected by hydrogen embrittlement. Photo: pjs2005 via Wikimedia Commons

As a result, the FAA has issued a civil penalty against Boeing which amounts to a total of $3,916,871. Boeing has 30 days to respond to the penalty notice.

Flight Global has quoted Boeing with regards to the issue:

“We are committed to continuing to strengthen our processes to ensure that quality issues in our production system are promptly identified, elevated and resolved.”

Boeing has also said that “All affected 737 NGs have been inspected and all slat track installations determined to be required have been completed on the NGs.”


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Fernando B menendez

well I notice you are reporting most of the time bad news about Boeing ,but neglecting to post all the faults of airbus including crashes ,hey I am all for safety and Boeing needs engineers in charge not lawyers and MBA’s, but the FAA is intent of sinking Boeing, also the FAAt needs engineers not lawyers and MBA’s .hey I trave and l want to be safe when I do .

Farhan Nazar

What do you mean they’re neglecting the issues of airbus planes?

They cover the engine issues of the A220 and Indigo’s A320 neo in depth on this site.


…and what crashes would that be? Could you please specify.

Meanwhile, perhaps you could do a little more searching on the website here, before commenting. I hate to do your work for you, but just a few articles down, is an article about an A320 shattered windshield.


Please do try to keep up.

Farhan Nazar

I have look at many articles since I discovered this website, I do not anyone to do any “work” for me. As for why Boeing has been in the headlines more? It’s not because any sort of bias, it’s simply because they’ve done screw up after screw up this year. Airbus on the other hand, other than some airline specific incident have been pretty much clean this year. And I don’t think an airbus plane have been involved in any major fatal crashes this year other than that Ural airlines emergency landing (which this site also cover btw )… Read more »

Moaz Abid

And the thing is, the bird strike is not airbus’s fault. It’s mother nature


Frank responded to Fernando B menendez’s post, not your comment.

Gerry S

The FAA is now on the spot. It is rehabilitating itself. It needs to show the world that it is credible as before. This is great for air safety. If there is a problem at Boeing affecting same then it is it’s sworn duty to correct it and administer punishment when it is due. All lives matter especially those locked inside a pressurized tun can at 32,000 feet.

Farhan Nazar

Oh Lord 🤦

Gerry S

To those(such as Fernando B) accusing this site of manufacturer bias: That is not so. I have seen no evidence of that. Here in the U.S. many live in the land of the three wise monkeys; hear,see, and speak no evil. News which is negative about somthing they hold dear even when totally accurate is considered as fake news. I have some issues with some respondents on this site who are of this ilk. The only issues I may have had with Simpleflying concerns grammatical errors and very few factual ones which are corrected when informed. This site does not… Read more »


Another example of stellar Boeing quality and ethics 🙁

Meanwhile, the FAA has started the formal re-certication process of the MAX 8 and 9. God help us all!

Bodley Fludes

If only the FAA would fine aerospace companies for penalising or dismissing genuine whistleblowers too. How many people who work in aircraft construction and maintenance, know exactly what is going on, and see awful things that should never be, and are either silenced or are too frightened of losing their jobs to speak up and save lives.


Yet another example of Boeing not caring about passenger safety just to make a quick buck, A $4 million fine shows that we can’t trust the FAA either. It is time to clean house in both departments.


It seems that Boeing wants to reduce earth population with its 737 Series aircrafts (MAX and NG).
B.F.C.I. – Boeing Flying Coffin Incorporated


5 years ago, if the had happened, I’d be absolutely shocked.
Now after all the issues with the 787 mismatch of parts in development & battery fires in service. The ongoing mess of the non-flying 777X, the new story of magnesium swarf in the wiring looms of earlier787’s and then the 737 MAX crashes & the information that has now come to light,
this is just another in a frighteningly long line of safety & development failings which Boeing has been ‘found out’ over…….
which leaves me wondering what other failings Boeing has successfully hidden from the regulators & operators.?


You forgot:
– The pickle forks in the 737 NG, and the FAA order to re-design and replace the engine cowling on all 6700 NGs;
– The allegations of deflective oxygen tanks in the 787, and the questions from Capitol Hill regarding the lightning conduction foil in the 787 wings.

p.s. This is the point where Gerry S will attack both of us (or, at least, me) for being “Anti-Boeing” 😉


That sends a message to all the suppliers around the world used in the way Boeing makes an airplane.

Tim Kyle

Believe it might be time for a leadership change at Boeing. Way to many things going wrong, and the responsibility starts at the top. Someone new (from within the company) with a fresh perspective and a good track record.

Disclaimer: Looking at this specifically from a Leaders perspective.