“very difficult to distinguish, visually.” except for a number stamped on them, AND THE PRICE!!!
Posted on 02/13/2020 7:01:34 AM PST by Enlightened1
...spokeswoman said the two parts are "very difficult to distinguish, visually."
I hate to dogpile on, but building otherwise identical bolts suggests the switcheroo was intended all along.
$72,000 worth of bolts is a decent chunk of money.
I did some work for a defense contractor many years ago. They tend to be rather meticulous about inventory of expensive parts.
I find it hard to believe that their cost accounting system didn't spit out an alert when fewer than the correct number of bolts were checked out of parts inventory. There SURE AS HELL would have been alerts if more than the expected amount were being checked out.
The engineering world has a maxim called "Murphy's Law", which goes "If anything CAN go wrong, it WILL".
This is not an expression of pessimism. It is an instruction to the engineer, that he MAKES SURE to minimize the number of ways that things could go wrong. Like making electrical plugs intended for different voltages and power levels physically different, so that a plug CAN NOT be placed in a wrong outlet. Like making sure a part CAN NOT be inserted backwards or upside down.
In this case, the engineers failed in their duty to ensure that the wrong type of bolt COULD NOT be mistakenly installed where it wasn't supposed to go.
I don't know, but I have a feeling that those aircraft will be arriving at Davis-Monthan earlier than planned.
The tedious, paperwork-intensive “Subsafe” program is supposed to prevent this from happening on our submarines (and seems to be extremely effective). I hope contractors can improve their quality control on aircraft without going that far overboard.
You have decoded the problem. You are exactly right. We aerospace engineers always specify design differences when possible, to prevent interchangeable parts from being used.
However it is not always possible. Here you have two fasteners with identical sizes and threads. Only the material is different. The design selected should have been the weaker fastener so that a mistake would make the system better. Shame on the engineers in this case if there are places where the stronger fastener is the only one that will work. In these locations, LM needs to fix the product. And I worked for LM. System engineers know what I am talking about.
Yes they are. And often in areas that once the assembly is complete very hard to access.
Or perhaps like a power steering pump on a Volvo s80 V8 that the intake manifolds had to be removed to access one friggin bolt. And NO aftermarket pumps anywhere. Strictly from Volvo. Repair the old one? Yeah, right. No chance of that these days. Oh well. :-)
There is an old racing expression:
“When in doubt-—Make it stout”.
Congrats on your new F-35.
It is the most over-engineered most cheaply built warplane ever. Only the finest and strongest materials and parts, some interchangeable, are used in its design and construction.
Disclaimer: Some disassembly and reassembly required. Armaments pods available at a ridiculously marked down price.
(/sarc)
Obviously hiring people with the 'enormous' mental facilities it must take to visually inspect the bolt you are inserting into a critical juncture has the proper identifying number must be beyond human resources ability..........but I digress, these must be union yobs. I believe it is common engineering practice to identify bolts by a number/letter combination. They charge enough for these damn bolts without re engineering and setting up a special production line.
The answer is simple, every one involved in the assembly needs to do their damn job! Where the hell was the QC Inspector when all this was going on and do they still have their job and if so WHY!
Probably did it to save money [koff koff] during prototyping and design testing.
If the ‘bolts’ are the same size did they mess up even worse by also putting on the incorrect collar(nut)?
“very difficult to distinguish, visually.” except for a number stamped on them, AND THE PRICE!!!
One of my pet peeves. Defies probability.
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