[filereaper]

Genuinely trying to understand.

Didn't the SR71 fly between LA and NY at above supersonic speeds? Don't military jets fly at supersonic speeds above land?

What makes this allowable in terms of sonic booms? Is it that they're much smaller and the their booms don't cause as much of a "wake" on the ground?

[rsynnott]

> Didn't the SR71 fly between LA and NY at above supersonic speeds? Don't military jets fly at supersonic speeds above land?

I think not routinely in either case? Most supersonic aircraft can't actually sustain supersonic speeds for a significant period; the Concorde and Tu-144 are, as far as I know, the only aircraft ever designed with supersonic flight as the effective _default_ mode of operation. For both planes, _getting_ to supersonic was rather expensive, and required the use of afterburners, so an ideal flight profile would involve ramping up to supersonic once, and then staying that way for the rest of the flight.

The SR71 was, unusually, _capable_ of sustained long-range supersonic flight, but I can't imagine it was routinely used above land when not actually on missions; why would it be?

[kube-system]

> The SR71 was, unusually, _capable_ of sustained long-range supersonic flight, but I can't imagine it was routinely used above land when not actually on missions; why would it be?

Everything a military plane does is a mission, and the SR-71 absolutely did supersonic training missions over the US.

And as I understand, the military can and still does do supersonic training missions over land, but they do it at higher altitudes and in locations where it isn't disruptive to population centers.

[ceejayoz]

The F-22 can also cruise at supersonic speeds without afterburners. https://en.wikipedia.org/wiki/Supercruise.

[rsynnott]

_Can_, but does it routinely outside of training/deployment situations? Like if you're just moving one from one side of the US to the other, you're probably going subsonic.

[adgjlsfhk1]

a couple things:

1. smaller lighter, and higher flying reduce the sonic boom size

2. way fewer planes

3. the military gets some latitude to ignore the rules that everyone else has to follow

[kube-system]

> Don't military jets fly at supersonic speeds above land?

It can happen, but it is disruptive at best. It isn't something you'd want happening around a populated area on a routine basis in peacetime. And it typically is not, unless under emergency circumstances.

https://www.youtube.com/watch?v=G8G-mgKycUM

[denton-scratch]

Thd only time I've ever heard a sonic boom was as a kid, on holiday in the south of France. They would regularly fly Mirage jets over the beach resorts. I suspect these flights were for when Gen. de Gaulle was in residence at the Chateau d'If.

[twelve40]

smaller, and SR71 could cruise at 85000 feet