Well at least with the massive complex of Heathrow Airport less than 2 miles away to the south west, he at least knew where he was located relative to Croydon if that was his original intended destination.
Heston had up until 1939 when WW2 commenced been very much London's second major airport in terms of overall movements, both domestic and international and would have been possibly London's major airport rather than Heathrow later, had expansion plans gone ahead prior to the build up of war preparations.