The Concorde was famous for its "high-altitude" cruising, typically flying at altitudes between 50,000 and 60,000 feet (roughly 15,000 to 18,000 meters). This is significantly higher than the 35,000-foot average for modern subsonic jets. At these altitudes, the air is thinner, which reduced drag and allowed the Concorde to maintain its supersonic speed of Mach 2.04 more efficiently. From the windows, passengers could actually observe the curvature of the Earth against the dark indigo of the upper atmosphere. This high-altitude path also meant that the Concorde flew above almost all weather patterns and turbulence, providing a remarkably smooth ride. In 2026, while supersonic travel is seeing a resurgence with companies like Boom Supersonic, the Concorde remains the historic benchmark for civilian high-altitude flight.