Instructions: Generate a correct and concise answer for the question based on the words in the context.
Input: Context : The Downend air crash occurred on 6 November 1957 when a prototype Bristol Britannia aircraft crashed in woods near Overndale Road in Downend, a suburb of Bristol, England, on its landing approach at Filton airport during a test flight.
Question : When did Downend air crash occur?
Output:
6 November 1957