In 1959 the Supersonic Transport Aircraft Committee recommended the construction of a fleet of long range intercontinental airliners which would fly almost twice as high and over twice as fast as those in service at that time; at Mach 2.0, twice the speed of sound. In 1962, the British and French Governments signed an agreement to develop the aircraft together. Exhaustive testing using a range of models was carried out in order to ascertain the ideal shape for the aircraft, and it became clear that a narrow delta wing would have sufficiently low drag for high-speed cruising and still have good handling characteristics at low speed and landing.