It doesn’t pass the commonsense test.
I bet it was a simple error.
If such a requirement is necessary for safety for private operations why wouldn’t the FAA mandate fitment?
They have over ten times the number of aircraft that we have.
Competent pilots I know would not spend excessive time above 10,000 without oxygen but the US regs allow for good judgement.
Lets say you are a farmer living in the outback and visit the coast once a month or so. There will be times when going above 10,000 and getting above the inversion layer would be sensible. But. Hold on you can’t because you do not have an oxygen system fitted!
Last edited by Dick Smith; 14th Jul 2021 at 07:14.