I worked opposite LHR for a company on the Bath Road in the late 70's.
A lady I worked with was friends with a British Airways 'groundie' (J.T.)
In return for a free flight from Biggin to Shoreham and back in my club 150, John, (with a cursory wave of his pass), gave me a tour of the hangars, including a VC10 (used just for training I think- it had just 6 seats in the cabin) and Concorde!
I sat transfixed in the L/H seat, as the engineers went about their business around us- Pure magic!
John always wanted to be a pilot, and I was thrilled some years later to hear that he had not only done just that, but was a F/O on Concorde!