The British airborne establishment was formed in June 1940 under the orders of the Prime Minister, Winston Churchill, in response to the German use of airborne forces during the Battle of France. When the equipment to be used by the airborne forces was being developed, it had been decided by officials at the War Office that gliders would be an integral component of such a force; these would be used to transport troops and heavy equipment, which by 1941 had been expanded to include artillery and some form of tank. By the beginning of 1941, the War Office had issued four specifications for military gliders to be used by the airborne forces. The first was Air Ministry specification X.10/40, which called for an eight-seater glider similar to the German DFS 230, which eventually became the General Aircraft Hotspur I; the second was specification X.25/40 which became the Slingsby Hengist, a fifteen-seat glider; the third was specification X.26/40, the 25-seater Airspeed Horsa; and the last, X.27/40 was for a glider that could carry a light tank or other heavy loads. The number of aeronautical firms able to design and produce gliders was limited, especially since several were already committed to producing other prop-driven aircraft for the government; as such, contracts for the gliders were allocated to firms as the government saw fit, rather than through any competitive process. Slingsby was chosen to develop "X.25/40" because it was believed to be too small to build larger gliders, and Airspeed would eventually build the Horsa. Because it had already developed the Hotspur, which first flew in November 1940, and was considered to have a sufficiently developed production capacity capable of producing a larger glider, General Aircraft Limited were chosen to develop X.27/40.