I was flying from the west coast of the US to the east coast @ 1990, and I’m sure at one point I heard the pilot say something to the effect, “If you look out your window, you’ll see the supersonic aircraft Concorde.”
I realize that that was a normal Concorde route, but I guess it’s possible that one of them might have been going to an air show? Can’t imagine what one would have been so far off the beaten path. In any case, I didn’t get to see it, if that was what he said.
It used to go from Dulles (DC) to Mexico City, so it’s certainly possible. It was also occasionally chartered for private groups.
I saw one once at JFK Airport and was kind of surprised at how small it was compared to the other jetliners.
Civilian supersonic flight was banned over US territory in 1973, meaning Concorde could only fly on oversea routes. It seems doubtful that one would ever be on a west-to-east route over the US, unless it was a ferry flight or going to a special event of some sort.
One thing that I knew, forgot, and just now re-learned is that Braniff(!?) operated the Concorde on a short lived route from Dallas-Fort Worth to Dulles in '79 and '80. That was alongside the more traditional Dulles to Mexico City route that Air France operated. So there’s a couple of possibilities above and beyond the charter operations that could also have resulted in a sighting…
I was flying west to east. I can’t attest to the direction of the alleged Concorde.
It was also pretty tiny on the inside, and had really small windows.
According to @Pork_Rind’s link, Brainiff did operate their weird DFW → IAD → LHR route for a little while, and the Dallas to Dulles part was subsonic. But that was a decade earlier than your memory.
So my guess is a subsonic ferry flight or air show. The few Concordes in existence pretty much flew east-coast to London and Paris exclusively for most of their careers.
I saw one once at Heathrow, in 2000. The bus we were on drove by it on the way to our aircraft.
Also saw one at Oshkosh air show, around 1990. For $600 you could take a short (40min?) flight. There was a B2 Bomber there too, but no flights offered. In fact, there was a perimeter armed guard unit keeping people away. The Harrier demonstration was fun but noisy.
Last one I saw was on the barge beside the USS Intrepid Air Museum in NYC… You can walk through it. It’s remarkable how tiny it is, inside it is very cramped.
Was the Concorde banned from subsonic flight over the US? Seems if you wanted one on the west coast you’d fly it cross country to get there.
Subsonic flight was allowed, but there was never any regular Concorde service from the west coast.
I nearly crashed once, driving on the M25 past Heathrow.
Planes landing over the road was a common sight, but Concorde, with its wheels down, the nose down in the landing position and the whole plane tilted right back, just like some enormous bird landing.
My other dramatic experience was when I was driving along a dead straight road and saw a plane coming towards me at treetop height. This was a Vulcan bomber and as he passed over me, a huge delta wing, he pulled the stick back (or whatever they did) and opened the throttles, I felt the kick of the backwash from the engines.
Concordes were used for exclusive charters in the early 90s. IIRC, one such tour flew from DFW to IAD (Dulles) and then on to London. Spend some time there and then take the QE2 back to NYC. As mentioned above, it had to fly subsonic over land and then it could fly supersonic over the water. I saw it once take off out of DFW.
That sounds like the Braniff route that @Pork_Rind described above. But that was in '79 and '80, and not a charter.
There’s one parked at the Museum of Flight in Seattle. You can go inside and walk end to end. It’s remarkably cramped and uncomfortable. No wonder it never (CSI sunglasses) took off.
The reasons it failed were the inability to make a profit and resistance from potential destinations to supersonic airliners.
Many wealthy individuals were willing to pay a substantial premium for speed and prestige, but not enough.
I wanted to ride on the Concorde when I was young but eventually I met someone who had taken it to France and Back. He told me I’d be extremely uncomfortable because it was so tight. He said he’d never do it again and he would have fit better than I would. By the time the flights stopped I didn’t want to fly anywhere anymore. Doesn’t seem like much of a missed opportunity in the end.
Do only aviation geeks read aviation-related threads?
The tendency to use airport codes instead of names suggests that assumption has been made. I think that some people who don’t even know their own airport’s code might choose to read this thread.
I can ID a moderate number of the codes on sight but not all. It could be that other Dopers know less of them than I do. They might appreciate not having to look up any codes they don’t know.
Ambiguousness is not our friend.
Two quick anecdotes from my time working close to Heathrow whilst Concorde was still in operation.
My office was just a few hundred metres north east of the perimeter and you felt you could almost peer into the windows as the planes landed. As a result our office windows were triple glazed to insulate us from the noise. About the only things to disturb the peace were Concorde landing, and the sub-woofers of the local lads in their cars.
There is a big staff parking area near Hatton Cross on the eastern edge of Heathrow. It is right in front of the south runway with landing planes scarily low overhead. Sometimes, especially with a low cloud base, a landing Concorde would set all the car alarms off.
And right by one of those car parks is ‘TBC’ (Technical building ‘C’). This is/was 2 floors of offices over a 9-10 story car park right in the middle of Heathrow. Concorde would pass directly in front (depending on runway in use) when taking off towards the East. My memories are probably clouded by time (mid-90s was my time there) but it seemed to be literally at eye level at that stage. TBH it was probably a little higher but still - ringside seats 
Apologies for the Almay stock - best image I could find to show the structure itself