Editing Transonic (section)

==Condensation clouds==
At transonic speeds [[Prandtl–Meyer expansion fan|supersonic expansion fans]] form intense low-pressure, low-temperature areas at various points around an aircraft. If the temperature drops below the [[dew point]] a visible cloud will form. These clouds remain with the aircraft as it travels. It is not necessary for the aircraft as a whole to reach [[supersonic]] speeds for these clouds to form. Typically, the tail of the aircraft will reach supersonic flight while the nose of the aircraft is still in subsonic flight. A bubble of supersonic expansion fans terminating by a wake shockwave surround the tail. As the aircraft continues to accelerate, the supersonic expansion fans will intensify and the wake shockwave will grow in size until infinity is reached, at which point the bow shockwave forms. This is Mach 1 and the [[Prandtl–Glauert singularity]].