[kube-system]

This tool would be capable of performing that measurement with 0.001" accuracy. https://www.harborfreight.com/feeler-gauge-32-pc-63665.html

Someone performing maintenance in their garage on an internal combustion engine would encounter the need to measure the same tolerances, for example, adjusting valve clearances. This is a common and accessible measurement task.

[cartoonfoxes]

Strictly speaking, it wouldn't. One of the interesting things the aviation industry deals with is a need for traceability of the metrology all the way back to NIST standards. That extra test, certification, and paperwork has a price. Compare the harbor freight example with this one: https://forneyonline.com/feeler-gauge-set-26-leaves-0015-to-...

[aunty_helen]

I'm not sure where you got this idea from, sounds like a lot of work.

It would be much easier just to calibrate the tool before putting it into service. And given that there is a routine calibration schedule for measuring equipment, there's no need to have some NIST paperwork certifying the metallurgy of the brass rivet holding your feeler gauge together.

The two tooling engineers I sat next to when I worked at a jet engine MRO would buy any tool they wanted from their parts catalogue. I can't remember the name of it now but it was yellow covered and about 6 inches thick.

They would buy the same tools you could get at any respectable hardware store. Snapon, Koken, TengTools were common. They bought good quality so it lasted, not so they could get NIST certificates with them.

In the engine manuals, for specific jobs, there would be specific tools you would need to use. These would be listed by part number. If you used any old torque wrench when the manual specified a particular part, you weren't in compliance. This could be picked up by an aviation authority when your paperwork was audited. Or of course, if you have an 'escape' where an engine gets put on a plane and then stops mid flight (second worst case scenario).

The same goes for the calibration of the tool, each time you torque a procedure you need to fill out the paperwork with the tool # that the engineers will have engraved on the side of it. If the records show that tool is overdue for it's calibration when it was used, best case scenario, engineer doing the procedure gets told off, tooling guys get a 'finding' and have to improve their system of tool tracking. Worst case scenario, people die. Which could result in the Quality manager getting thrown in the clanger.

[kube-system]

I just meant it's 'capable' in context of the above question of engineering capabilities. But you're very right that aviation requires expensive safety and compliance procedures on top of that.

[ryandrake]

Yea, they are both capable of doing the same job, but one comes with a $104.01 piece of paper that proves that a clerk in an office stamped another piece of paper and filed it away in a cabinet, which makes it legal to use with a certified airplane.

[SAI_Peregrinus]

You can take just about any measuring tool to a calibration company and get the certificate. Indeed, you MUST do this on a regular basis: calibration is a set of measurements of a system over time. Single-point-in-time calibration is worthless for showing drift. You can also get things tested at a range of temperature and humidity levels, high-grade lab standards may get calibrated at multiple temperature & humidity levels every 6 months.