The GAL.48 was primarily designed by F.F. Crocombe (team leader) to the Air Ministry specification X.10/40, and was to be similar in design to the German DFS 230 assault glider which had been used in the Battle of the Netherlands. The first prototype of the glider, designated GAL.48 and which would receive the service name Hotspur Mk I, flew in November, only four months after General Aircraft Ltd had been given the requirement for the glider. An initial order of 400 Hotspurs was placed with General Aircraft Ltd in September by the Ministry of Aircraft Production, nearly two months before the prototype first flew.