Just go into the Santa Monica Airport.
Darbury breathing freely.
We left Sacramento from McClellan Airfield . It's a decommissioned airforce base with a huge runway. This is a real treat for a plane like a Cessna 182, plenty of runway for takeoff and landing. We got into the air to catch excellent tailwinds southbound. The Cessna has a turbo on the motor - that means we could punch up to 19 thousand feet / 5791 meters. The air's thinner up there so there's less oxygen to mix with fuel. The turbocharger forces air into the engine for a consistent rate of climb up to altitude.
The Cessna doesn't go too much higher than what we were flying at. And, unlike most commercial aircraft, the cabin isn't pressurized. To breath, you have to wear a cannula - a tube that flows bottled oxygen into your nose. The great feeling of being on oxygen makes the great feeling of flying even better!