And when standing on the ground, the yell is louder, even though the military spent 80 million dollars on the jet.

to be clear, i wasn’t the one that made that comparison. Naturally you can fly planes at altitudes other than one specific number, that seems to be a feature of most planes.

i believe generally, in the space of planes, the ones that fly in the sky, not the mathematical ones. It refers to an operating altitude. However, i was using it to refer to that specific altitude. “operational altitude” for something like a military jet is not going to be specifically defined, compared to something like, a boeing 737 for example. There is likely to be a maxmimum operational altitude, naturally. Planes need air to fly through, obviously. But that’s irrelevant here, we’re talking about the ground.