Condensation similaire, à l'approche du transsonique en bout d'hélice d'un Iakovlev :
Plus de détails à
http://www.wilk4.com/misc/soundbreak.htm avec une image similaire :
Breaking the Sound Barrier (and Vapor Cones around Jets)
Here are some fascinating (for some people anyway) photos and videos of interesting condensation clouds that form around jets as they fly at or near the speed of sound, (often called "going through the sound barrier" or "accelerating past the speed of sound"). Under the right conditions, and even at lower speeds, they sometimes cause a vapor cone effect.
Understand that these Prandtl-Glauert condensation clouds can also occur at lower speeds, and are not really a visible manifestation of some kind of a sound barrier being broken.