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
GNU Mach GNU Mach GNU Mach is an implementation of the Mach microkernel. It is the default microkernel in the GNU Hurd. GNU Mach runs on IA-32 machines. GNU Mach is maintained by developers on the GNU project. It is distributed under the terms of the GNU General Public License (GPL). Early versions of the Hurd were developed on top of CMU's Mach 3.0. In 1994, CMU stopped working on Mach, and the GNU Project switched to the University of Utah's Mach 4. The kernel known as "GNU Mach" was derived from Mach 4 once Utah stopped development. The first ChangeLog entry