LA to New York or San Francisco to Honolulu in 2 to 3 hours would be a game changer. You could probably fill a plane at least once a day on those routes for a handsome profit.
Once I flew north-west at the time of sunset. I had the view of the most beautiful big red sun right at the edge a sea of snow white clouds for more than an hour.
As a pilot, Americans are incredibly sensitive to aircraft noise. And regulators do all sorts of stuff to route planes around noise sensitive areas.
It breaks noise regs to fly most subsonic 1960s eras jets with their original engines these days, you have to modify them with hush kits, etc.
They forced a lot of these very American jets to be quiet for the sake of just the landing and takeoff phases. I have a hard time seeing that they would/will find a way to make sonic booms acceptable to the general public.
I suspect many more Americans could potentially sue the airline for the noise than English or French, due to the structure of the respective legal systems. So the financial risk of overland operations over the US, even with the ban lifted, could be too high still.
I thought about Hawaii also. Rich cities in Northeast Asia might also be a good target: Tokyo, Singapore, Seoul, Shanghai, Beijing to Hawaii might be good targets for weekly (or charter) flights. The tricky part (except Tokyo) would be negotiating supersonic flyover rights. I cannot imagine that Japan would be excited to have regular supersonic flights over their main island from Seoul or Beijing.
Regarding LA<->NYC, I think you could make a dent in that market with an all business class flight that flies slightly less than Mach 1 (0.95 or whatever) and has special security screening and baggage handling. People might be willing to pay 30-50% more compared to business class on a regular flight.
Last: Is there a video game like Theme Park or Railroad Tycoon that allows for the simulation of an airline market? That could be fun.
