FAA rules result in engines designed in WW2 using leaded gas & carbeurators remain state of art.

Can’t get anything newer approved.

Likely couldn’t get WW2 technologies approved without grandfather clauses…and those were never tested since beating the germans was more important at the time.

Who cares where the metal used in a washer was mined?

Up to includes zero.

On the side is where the carotid arteries are. I suspect that blood going the brain might be a slightly important.

Appleseed