There aren't any modern planes still using turbojets. I think the Concorde might have been the last (ceased operation in 2003.) Combat jets often have very lo

There aren't any modern planes still using turbojets. I think the Concorde might have been the last (ceased operation in 2003.) Combat jets often have very low-bypass ratio turbofan engines though. A true turbojet has a 0 bypass-ratio; a lot of turbofan fighter jets have bypass-ratios under 1, while the engines on a 787 have a bypass-ratio of 10. https://en.wikipedia.org/wiki/Bypass_ratio#Engine_bypass_ratios https://en.wikipedia.org/wiki/Bypass_ratio#Engine_bypass_rat...