However, legally planes must be at least 1000 feet above any object on the ground, and must be able to land clear of any congested area in the event of an engine failure. Therefore small planes generally fly between 2000 and 10,000 feet. It all makes sense when you know the reasons for it!

Yes, planes can and frequently do fly at 10,000 feet, though it serves different purposes for different types of aircraft. For commercial jets, 10,000 feet is a critical "transitional" altitude; it is where pilots typically turn off the "sterile cockpit" rule and where they must slow down to a maximum of 250 knots (unless authorized otherwise). Jets only fly at this altitude during the initial climb or final descent, as it is much less fuel-efficient than their cruising altitude of 30,000+ feet due to higher air density and drag. However, for propeller-driven aircraft and small "General Aviation" planes (like Cessnas), 10,000 feet is a common cruising altitude. It is low enough that they don't always need supplemental oxygen or cabin pressurization (which is often required above 12,500 feet), but high enough to clear most terrain and weather. In 2026, 10,000 feet remains the "safety floor" for many emergency procedures; if a jet loses cabin pressure, the pilots will perform an emergency descent to this altitude where the air is thick enough for passengers to breathe without masks.