Originally Posted by champignon

Putting aside your impression that mask wearing on an airplane in flight, carrying mostly vaccinated passengers and crew, has any effect whatsoever on measurable covid infection rates (I would say, NO, it does not, and there is no science out there proving that it does), I sincerely doubt that a government, any government, can mandate what an airplane licensed and operated from another country and in international airspace, does. While in US Airspace I'm sure that the US Gov't CAN do this, but when out of US Airspace, international agreements and the rules of the flag country will dictate what is required.