- **Commercial Airliners:** Both [Concorde][1] (service ceiling FL600) and the [Tupolev Tu-144][2] (service ceiling FL660) could reach FL600. Most airliners have a service ceiling of around FL410 though. - **Business Jets:** According to [this article][3] the highest service ceiling for various business jets is at FL510, so none can reach FL600. - **Military Reconnaissance Aircraft:** The [Lockheed SR-71 Blackbird][4] had a service ceiling of FL850 and routinely operated above FL600. Many other aircraft in this category (e.g. [MiG-25][5], [Tsybin RSR][6], [U-2][7]<sup>1</sup>, [RB-57F][8]<sup>2</sup>, [M-17 and M-55][9]) can also fly above FL600. - **Military Fighter Jets:** Most fighter jets have a service ceiling below FL600, but there are a few that can fly higher (e.g. [F-15][10] and [F-22][11] with service ceilings of FL650, the [MiG-25][5] again, and [MiG-31][12] with the highest service ceiling of FL820+ for a fighter). High altitude balloons and rockets can of course fly higher. --- <sup>1</sup>Pointed out by Zeiss Ikon. <sup>2</sup>Pointed out by Fred Larson. [1]: https://en.wikipedia.org/wiki/Concorde#Specifications [2]: https://en.wikipedia.org/wiki/Tupolev_Tu-144#Specifications_(Tu-144D) [3]: https://www.aerospace-technology.com/features/featurethe-sky-is-not-the-limit-the-highest-altitude-passenger-planes-4186188/ [4]: https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Specifications_(SR-71A) [5]: https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25#Specifications_(MiG-25P) [6]: https://en.wikipedia.org/wiki/Tsybin_RSR [7]: https://en.wikipedia.org/wiki/Lockheed_U-2#Specifications_(U-2S) [8]: https://en.wikipedia.org/wiki/Martin/General_Dynamics_RB-57F_Canberra#Specifications [9]: https://en.m.wikipedia.org/wiki/Myasishchev_M-55 [10]: https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15_Eagle#Specifications_(F-15C) [11]: https://en.wikipedia.org/wiki/Lockheed_Martin_F-22_Raptor#Specifications_(F-22A) [12]: https://en.m.wikipedia.org/wiki/Mikoyan_MiG-31