Mach tuck significant in causing a tendency to dive, delta-winged aircraft with no foreplane or tailplane in the first case and, for example, the Lockheed P-38 in the second case. Alternatively, a particular design may have no significant tendency, for example the Fokker F28 Fellowship. As an aerofoil generating lift moves through the air, the air flowing over the top surface accelerates to a higher local speed than the air flowing over the bottom surface. When the aircraft speed reaches its critical Mach number the accelerated airflow locally reaches the speed of sound and creates a small shock wave, even though the
Mach (kernel) system would be implemented by starting with the existing BSD code, and re-implementing it bit by bit as inter-process communication-based (IPC-based) programs. Thus Mach would begin as a monolithic system similar to existing UNIX systems, and evolve more towards the microkernel concept over time. Mach started largely as an effort to produce a cleanly defined, UNIX-based, highly portable Accent. The result was a short list of generic concepts: Mach developed on Accent's IPC concepts, but made the system much more UNIX-like in nature, even able to run UNIX programs with little or no modification. To do this, Mach introduced the