For all warbird enthusiasts the former Duxford Air Force Base is the Mecca in Europe. On this beautiful site in North London, a band of enthusiasts maintain and fly the unique Boeing B-17 Fortress. The plane, which bears the sweet name of Sally B, performs numerous flight demonstrations across the continent every year.
This aircraft is exceptionally well showcased by Roger A. Freeman in this reference book:
The B-17 Flying Fortress Story. Design – Production - History