Shaped Sonic Boom Demonstration shock wave by a chase plane, the SSBD demonstrated a reduction in boom by about one-third. Several of the flights included NASA Dryden's F-15B research testbed aircraft following to measure the F-5E's shock wave signature close-up. During the flights, many shock wave patterns were measured by the F-15B at various distances and orientations from the F-5E. An unmodified F-5E flew a few seconds behind the demonstration aircraft to provide a baseline sonic boom measurement to validate the reduced boom produced by the demonstrator. A U.S. Air Force Test Pilot School Blanik L-23 glider carrying a microphone on the left wingtip,
Mach wave the schlieren method, to obtain data about the flow in nozzles and ducts. Mach angles may also occasionally be visualized out of their condensation in air, for example vapor cones around aircraft during transonic flight. Mach wave In fluid dynamics, a Mach wave is a pressure wave traveling with the speed of sound caused by a slight change of pressure added to a compressible flow. These weak waves can combine in supersonic flow to become a shock wave if sufficient Mach waves are present at any location. Such a shock wave is called a Mach stem or Mach front. Thus,