In The Flying Crusaders, Hookley Green was an area in the fen country which had been used as a practice landing ground by American aircraft stationed in East Anglia during the Second World War. Located not far from Mancroft Castle, it was a flat expense of ground with a windmill as a landmark. Galton, a US air force sergeant was supposed to fly the "Flying Crusader", a vintage aircraft, to Hookley after buying it at the auction held in Mancroft Castle. There, Joseph Silberman, a renegade American, was waiting to take delivery.
Hookley Green is a fictional location.