Kosher in or near airport in London, UK?
Caveat: the one time I really needed these sandwiches they had not been delivered that day.
It was back in 1999, on tzom gedalia, and I had deliberately booked myself on a flight that would take off about an hour before the fast was over, so that I'd be getting my dinner just when I wanted it. But the best laid plans and a' that, I missed my plane. Got booked on the next one, but of course there would be no kosher meal for me. And in the meantime I was in the airport, with the fast approaching its end, and nothing to eat. I'd heard that these sandwiches were available at a newsagent, somewhere in the airport, so I went looking for them. I checked every newsagent I could find, and asked at each whether they knew where the kosher sandwiches were to be found. Eventually I found one place that knew what I was talking about, and was in fact the place where they were usually sold, but sandwiches there were none, they hadn't come that day. And of course they hadn't come the previous two days either, because of yomtov. Perhaps they thought that as it was a fast day there'd be no demand for sandwiches at the airport, or perhaps they took the day off to nurse their own fasts, or perhaps the delivery was just spotty and sporadic at the best of times. I don't know, but I really hope it's improved in the past 8 years. (I've been to LHR since then, but never long enough to feel the need for food.)