A bit before this time, I think. My grandfather's business, quantity surveyors, had an office in a prefab on the South side of the airport until about 1954. He was very social and probably got most of his business through "Days at the races" and gambling parties at our house.
My fifth birthday party was held in the Nissen hut that was the airport restaurant. We got a tour round the Comet which was the newest thing and then some bonfires out at the end of the airport near the resevoirs.
When I was at home he took me to his office on Friday mornings, Putney to the Airport, an hour reading while he did some work, small writing on big ledger sheets, and then we would go to the Restaurant for lunch. They had an Hors d'oeuvres trolley with rotating layers that was a favourite and then fried fillet of plaice with chips and peas as I was too nervous to order anything else! (Six years old!) (I notice MS Office spelling does not include Hors d'oeuvres!)