The 214ST demo machine would have been in the area about Aug 1979, I remember sitting in some greasy spoon in the middle of Horley when I heard the 'ST' got airborne in the Redhill circuit and came down the London-Brighton rail line on the usual westerlies active SVFR Gatwick clearance @ 1500'. Little old ladies fainted in the street, I thought it was tremendous, 'Apocalypse Now' had also just been released and I got a first hand illustration of huge masses of air being moved about.
The Viscount (I can almost remember the operator but with gray cell mass extinction...) and the CAAs' HS748 make a nice backdrop.
TOD