Corrosion issue stops F-35 deliveries for a month

A MRO crew at Hill AFB discovered an abnormal level of corrosion on fasteners used to hold fuselage panels in an F-35A's undergoing inspection. The subsequent investigation revealed that a lack of primer is the cause. The existing 250 F-35's will have to undergo inspections and repair and the line itself will be corrected to make sure new aircraft do not have the issue.

Its not uncommon for this type of stuff to crop up and it seems it was caught early on. The article indicated existing aircraft will be fixed during inspections

www.flightglobal.com...

a reply to: FredT

$130,000,000 per jet. I would hope they could get the fasteners right.

At least someone caught it before the corroded fasteners do what corroded fasteners do. And on a jet it can be ugly.

Glad it was caught before it became a bigger issue.

a reply to: FredT

"Its not uncommon for this type of stuff to crop up and it seems it was caught early on. The article indicated existing aircraft will be fixed during inspections."

If that is an accurate statement, something is drastically wrong with our BEST manufacturing procedures if this is "not uncommon." We are talking about the very most basic of quality control here with the simplest of parts.

Technology is a poor substitute for nature. Technology is a prime example of Murphy's Law: "If something can go wrong it will." The more complex the technology the more "somethings" there are to fail. When common fasteners are substandard, particularly on this aircraft, something is wrong with our systems.

I was going to say something about technology (there is a polymer that when heated becomes a ceramic, a simple of coating of that would solve the problem).

But looking at the Navy's collisions, thinking of some of Zaphod's crash reports, and how little things can create major problems if over looked, I feel that process complacency is the real root of the problem.

You do a thing a million times it becomes boring. Then, all it takes is one time and then all h3ll breaks loose.

Root cause analysis is what it is called. We do post mortems on computer systems so no aircraft falling from the sky but nearly all the time it is because somebody did not follow their standard operating procedure because, "I already know how to do that" is their attitude. SOP keeps you from having to memorize things. "Step 1 - Unload fasteners into painting machine. Step 2 - Load primer into paint machine. Step 3 - Set paint machine to primer..."

Yeah, a bit robotic but there is no complacency. eta: Or it is reduced.

a reply to: Aliensun

Being a business owner myself, it's really difficult to get "it" right "all" the time and make "Everyone" happy. Not an excuse, just saying, you make mistakes.

While ridiculously expensive and probably way over priced to repair per plane, at least they have a solution. If I could bill some moron 130 grand for paint and get away with it I probably would be doing the same.

The difficulty is when you have hundreds of subcontractors, it only takes one bad batch of something to really get difficult to diagnose/replicate problems. Only takes one quality-control issue in some small business initiative to potentially snowball.
The SOP-thing above is huge. We found out we had unforeseen issues once and finally traced it back to an autoclave operator who just did his own thing. The big issue was that he did this for the R&D work, and then his portion of the production run of this component. His stuff worked, so first everyone assumed the issue was the other guys operating the autoclaves on a 3-shift project (about half of whom were new and brought in on contract just for thess new shifts). In fact, he had been doing his own thing the entire time and not following the "recipe" if you will, all the way back from R&D. So now we had 5/6 of this particular first run that was right on the border of the acceptable spec. Took a big loss and a delay to first test and diagnose everything to figure out both what we had and what the hell was going on before deciding to replace everything to get solidly back on the right side of the spec. Very bad times because one wise guy decided to start treating his job as more art than science.

I'm betting it was a computer error. It stopped painting at a certain spot and was not covered or the spray was turned off microsecond short

Sounds like an omission to add primer to drilled holes rather than a fasters issue, or did I read it wrong?

You want to know how bad/easy it is to fk up?

One of our Eurofighters had an event where the cockpit was filled full of toxic smoke, luckily it was on power up, not flight so canopy was opened and pilot evacuated.

Cause was a batch of MFDs (MHDDs on the Tiffy) which had a chip placed the wrong way around in the PSU of the unit.

Smiths Industries made that and they are not a shoddy outfit.

ISO9001, millions of products flying in thousands of aircraft with not many issues.

Doesnt matter how many checks and balances you put in place to de-risk things, things can go wrong.

Also, dont know if this common knowledge but I was involved in the purchase of Corrosion Sensors, these are placed around the F-35 and form part of the data which is downloaded post light to keep an eye on the jests integrity.

Very smart aircraft!

a reply to: Aliensun
Everything that flies has SOP for parts production. Surprisingly, most aerospace production processes are performed by a human, due to the relatively small production quantities.

In this case I would guess that the primer is applied to the holes by a human with a brush and some have been missed. The procedures will be changed to ensure it doesn’t happen again.

With 1000s of lengthy production and test procedures per aircraft, small issues like these are relatively common as aircraft enter into service.

I think its parts drilled off and cleaned up without having them reprimed.Fasteners are CAD plated (cadmium) and usually coated in a yellow anti corrosion grease with assembly.After assembly the assembly is reprimed before painting.Someone miss a step?

originally posted by: Blackfinger
Fasteners are CAD plated (cadmium) and usually coated in a yellow anti corrosion grease with assembly.....Someone miss a step?

Yes, its called Mastinox. Really good for the promotion of nasty cancers. But the point is everyone in the industry has know about priming holes with it for at least 60+ years. "Forgetting" to do that step in such a program with supposedly so much oversight isn't really an excuse. Its sheet metal 101 as you know only too well Blackfinger. Just another example of how f***ed up this program is.

a reply to: thebozeian

You can't say that this is an example of how screwed up the F-35 is. Other programs have done far worse and cost a lot more. The F-22 had some pretty significant issues with the wing-body join, and aft booms during the early production run. This is an industry wide problem and has been for years.

a reply to: thebozeian
Layers of protection mate