Nevertheless, certain exceptional aircraft like the Concorde and the Tupolev Tu-144 have managed to ascend to altitudes of FL600 (equivalent to 60,000 feet).

Very few aircraft are capable of sustained flight at or above 60,000 feet, an altitude known for its thin air and extreme conditions. The most famous is the Lockheed U-2 "Dragon Lady," a high-altitude reconnaissance aircraft that can operate at altitudes exceeding 70,000 feet. NASA also operates a specialized version, the ER-2, for atmospheric research. The legendary SR-71 Blackbird, now retired, could fly at over 85,000 feet. In the realm of military jets, the F-22 Raptor and F-15 Eagle have service ceilings listed near 65,000 feet. For civilian flight, the Concorde famously cruised at 60,000 feet to stay above weather and subsonic traffic. In 2026, high-altitude long-endurance (HALE) drones like the Northrop Grumman RQ-4 Global Hawk routinely fly at 60,000 feet for surveillance missions. Some high-end business jets, such as the Gulfstream G700 or the Bombardier Global 7500, have certified ceilings up to 51,000 feet, which is impressive but still significantly below the 60,000-foot threshold reserved for specialized reconnaissance and experimental aerospace vehicles.