[caf]

Concorde did actually fly over land - Braniff Airways operated it between Washington DC and Dallas Fort Worth under a short-lived, strange 'tag flight' arrangement (where the aircraft would continue on from Washington to London / Paris under BA / AF crews).

This segment was sub-sonic, though.

[dingaling]

And for each US domestic rotation each individual aircraft was reregistered onto the US N-register, and then back onto the UK or French register for the Atlantic crossing.

At that time only N-reg aircraft were pemitted to operate internal commercial US flights.

To simplify the process the BA Concordes were allocated unique-for-the-UK alpha-numeric registrations which could have their 'G-' prefix hidden by speed-tape:

http://www.braniffpages.com/n94aa.jpg

[jrnichols]

Here's a link to an old Braniff schedule showing the Concorde as a route out of DFW...

http://www.departedflights.com/BN102879p52.html