Mach number a small area around the object's leading edge. (Fig.1b) Fig. 1. "Mach number in transonic airflow around an airfoil; M < 1 (a) and M > 1 (b)." When an aircraft exceeds Mach 1 (i.e. the sound barrier), a large pressure difference is created just in front of the aircraft. This abrupt pressure difference, called a shock wave, spreads backward and outward from the aircraft in a cone shape (a so-called Mach cone). It is this shock wave that causes the sonic boom heard as a fast moving aircraft travels overhead. A person inside the aircraft will not hear this.
Bluebird Mach 1.1 Bluebird Mach 1.1 Bluebird Mach 1.1 (CMN-8) was a design for a rocket-powered supersonic land speed record car, planned by Donald Campbell but thwarted by his subsequent death during a water speed record attempt in "Bluebird K7" in early 1967. Donald Campbell decided a massive jump in speed was called for following his successful 1964 LSR attempt in "Bluebird CN7". His vision was of a supersonic rocket car with a potential maximum speed of 840 mph, referred to as "Bluebird Mach 1.1". Norris Brothers were requested to undertake a design study. Campbell, ever superstitious, chose a lucky date to hold