# What is the fastest unpressurized aircraft?

What is the fastest unpressurized aircraft with oxygen masks that can carry people?

• Living people or dead (dying) ones? – user3528438 Jul 24 at 22:01
• What was the highest start for a skydive not involving a pressure suit and how fast did the skydiver get going? Or did you mean in level flight? Also see other comment - consider any WW2 fighter, nearly all of which were unpressurized. With a mask you can go way above 16K without pressurization! – quiet flyer Jul 25 at 2:32
• I'd say X-15. Don't think it was pressurized and it can go mach 6. – Pheric Jul 25 at 3:58
• @Pheric all of the X planes were in some capacity pressurized going back to the X-1 and including the X-15. The all mainly used a Nitrogen pressurization system with pilot fed oxygen to effectively keep the cockpits fireproof. – Dave Jul 25 at 5:37
• Being petty here perhaps, but aircraft capable of being pressurized are also capable of dumping cabin pressure. Therefore an F-18 Hornet could be unpressurized and still go mach 1. So what you are really asking is "what is the fastest aircraft that is incapable of being pressurized?" – Michael Hall Jul 25 at 16:54

Messerschmitt Me 163 Komet was unpressurized, rocket powered WWII interceptor.

The operational ceiling was limited by what the pilot could endure for several minutes while breathing oxygen from a mask, without losing consciousness. Pilots underwent altitude chamber training to harden them.

Special diets were prepared for pilots to prevent gas expansion in the intestinal tract during ascent.

The "never exceed" speed of this aircraft officially was 900 km/h but that has been exceeded anyway, when the test pilot Heini Dittmar reached 1,130 km/h.

• Cirrus SR22 ... are some fastest unpressurized aircraft citation needed – zymhan Jul 25 at 12:44