I suspect that anyone who has watched the series and knows Oxford well can readily answer this question.
At the end of episode six in Masters of the Air, Harry Crosby and Sandra Westgate (played by Bel Powley) are returning to the Oxford college where they are staying, and at the entrance, a man approaches Westgate and says, "Subaltern, we've been scouring the college for you. An urgent message." She then leaves immediately, riding a bicycle that she is "borrowing" down the street. On what street or in the front of what college was that scene in Masters filmed?
I know some Oxford scenes were shot on Catte Street by Radcliffe Camera and the Bridge of Sighs.