Critical Mach number and slow down as it travels around the aircraft's structure. When the aircraft's airspeed reaches the critical Mach number, the speed of the airflow in some areas near the airframe reaches the speed of sound, even though the aircraft itself has an airspeed lower than Mach 1.0. This creates a weak shock wave. As the aircraft exceeds the critical Mach number, its drag coefficient increases suddenly, causing dramatically increased drag, and, in an aircraft not designed for transonic or supersonic speeds, changes to the airflow over the flight control surfaces lead to deterioration in control of the aircraft. In aircraft
Mach Song population segments not reached by their media partners. On certain issues, Mach Song Media mobilizes local faith and community organizations to reach deep into their constituencies. So far they have worked with over 200 such organizations on various issues and have the capacity to reach 1,000 faith and community organizations in the Vietnamese communities across the US. "Boat People SOS" has invested over 1 million dollars to develop its own network of Vietnamese-language mass media. This network includes Mach Song monthly publication, Mach Song radio programs and Mach Song television programs. If necessary, Mach Song can readily increase the circulation