For those who were convinced it was Shoreham, I probabyl should have mentioned, it has been used, twice I think. I’m not sure of any episode titles, but I think there is one where someone is murdered by a poison dart whilst flying on a DC-3 and I think that used Shoreham.
Given their desire to find 1930s buildings, they might well have used the interior of Shoreham’s terminal as something other than an airport, so that might explain at least one of those.