Fun story: when the Soviets tried to reverse-engineer captured B-29s bombers (into Tupolev Tu-4s) they had a lot of trouble because their production of sheet aluminium, rivets, etc. was done in metric sizes, whereas the B-29 used imperial-sized components, and thus extensive re-engineering was required to compensate the slight differences in thickness (and thus in weight and balance) of all components.

I wonder if this justifies the US adherence to the imperial standard - meaning it acts as a basic barrier to entry for other countries who use the "world" standard.

Compatibility usually gains you more than you lose. If you can't make US planes with parts from the rest of the world then that does mean other countries can't make US planes, but that also means that the US manufacturers can't import parts from elsewhere.

The F-35 has components made all over the world, but was designed in the US. Is that plane metric?

I would assume/hope so? Lockheed of all companies should be on top of that after the mars probe incident.

sort of like the use of analog comms on the Galactica right?

Not quite the same thing, but since you mention Galactica and her non-networked systems, I believe watching this show should be required of anyone even tangentially considering work in an IoT project.

Try making a paper airplane with Galactica’s octagonal sheets of paper!

And Airbus only uses imperial bolt sizes.

> imperial standard

The US does not use Imperial. It uses US Customary.

This differs from Imperial in many ways especially for volume measure. And of course Imperial is not a standard.

For one thing a pint is still (roughly) a pound.