Critical Mach number Critical Mach number In aerodynamics, the critical Mach number (Mcr or M* ) of an aircraft is the lowest Mach number at which the airflow over some point of the aircraft reaches the speed of sound, but does not exceed it. At the lower critical Mach number, airflow around the entire aircraft is subsonic. At the upper critical Mach number, airflow around the entire aircraft is supersonic. For an aircraft in flight, the speed of the airflow around the aircraft differs considerably in places from the airspeed of the aircraft; this is due to the airflow having to speed up
Ford Mustang Mach 1 a cold air "snorkel" and a partial Ram Air at speed. 2004 saw only minor cosmetic changes to the Mach 1. 2004 Mach 1s can be identified by bare aluminium finished valve covers, as opposed to the 2003's black finished covers. Outside, 2004 Mach 1's wear 40th anniversary tags ahead of the doors while the 2003 has the traditional Mustang Running Pony and Tri-Color bar. The lone interior change was the deletion of the overhead "cargo net" mounted on the headliner. Despite pre-production rumors, the horsepower and torque ratings were not increased in 2004. Power rating was and . With