The two officers and their newly formed unit were provided with four obsolescent Armstrong Whitworth Whitley bombers and a small number of Tiger Moth and Avro 504 biplanes, for towing purposes. Around this time the War Office and Air Ministry began to draw up specifications for several types of military gliders to be used by the unit. The resulting gliders were the General Aircraft Hotspur, General Aircraft Hamilcar, Airspeed Horsa and the Slingsby Hengist. These designs would take some time to be implemented and produced, however, and for the time being the fledgling unit was forced to improvise.