A few modestly interesting videos, especially if you want to depict rapid depressuization of a high-flying aircraft.

First a test with a jetliner. This seems to be a 7 psi pressurization check carried out on the ground. Rather than being pressurized at somewhat less than sea level pressure and blowing down to very low pressure at high altitude, this started off at *more* than sea level pressure, and blew down to whatever the local air pressure was. The end result is more or less the same; the structure of the aircraft undergoes the exact same stresses (which was probably the point of the test). The visual response is, *I* *think,* more pronounced here than it would be at altitude, because the high pressure ground test likely had more humidity to start with – and thus convert to visible cloud – than a high altitude scenario would have. Bonus: best YouTube comment had to be… “This must be the pilots first day. Putting the clouds on the inside of the plane instead of the outside is a rookie mistake.”

And another depressurization test, this time of a U-2 pilot and his “space suit.” You can see the cabin fill with vapor briefly… and you can see how that carefully fitted suit doesn’t fit worth a damn anymore promptly after depressurization:

And another depressurization of a test chamber (from 8,000 feet altitude to 18,000), showing the insta-cloud: