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.
Ford Mustang Mach 1 1 models of the previous four years. The 302 Windsor returned in 1975, rated at and of torque, giving the Pinto platform a notable performance boost. Also available was a 4-speed manual. The Mach 1 remained mostly unchanged in 1976, as a new performance model - the Cobra II - was introduced alongside. 1977 proved to be the weakest sales year of the Mach 1 to date, selling only 6,719 units. The nameplate remained for one more year, upon when it was discontinued with the advent of the third generation Mustang in 1979. During the 1990s, the preeminent performance Mustang