Is it? The Concorde would fly at subsonic speeds over land and move to supersonic over the Atlantic. Given the reduced flight time at supersonic speeds I thought economic considerations prevailed.
In a world where there had been many viable Concorde routes, this could all have worked out a lot differently, Concorde B might have happened (which would have allowed a Pacific crossing), and maybe we'd still see supersonic airliners.
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?
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
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?
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.
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.
I live in south-east Canada in the province of PEI and I hope no supersonic aircraft are made. Right now all commercial air traffic from NA flies right over my house. Especially every evening the rumble of high flying jets can he heard. It's not loud but it's certainly noticeable for something 10,000m above me.
In the 90s and 2000s you would have had 747s and a340s doing that nonstop without Anchorage or Honolulu, so if anything that would have made concorde B have an even shorter shelf life.
But shortly after Concorde's design was locked in high bypass turbofan engines were developed whose fuel efficiency was way higher than turbojets, and indeed much higher than the jump to supersonic flight could achieve. Now it was a choice between speed and fuel efficiency. This really could have gone either way, but when Boeing got out of the SST game they lobbied for overland supersonic flight to be restricted because of sonic booms, which eliminated the potential domestic market. Concorde was reduced from the future of air travel to an offshoot for a niche market.
Still it was profitable. People were willing to pay a premium for faster travel, it just wasn't a big enough success to warrant further development. The aircraft aged, unable to take advantage of many of the improvements that came to subsonic jets, and there was no replacement in sight. The Concorde was increasingly expensive to operate compared to more modern aircraft, not because of fuel but because of maintenance and staffing. Between a high profile Concorde crash in 2000, then the reduction in aircraft travel after 9/11, and the security increases which essentially tacked on 2 hours to every trip by air, the Concorde ceased to be viable.