A jet is an aircraft that uses a jet engine. Unlike propeller aircraft, jet aircraft generally fly at an altitude of 10,000 to 15,000 meters. At this altitude, jet aircraft can achieve maximum efficiency.
The aircraft, which first used the principle of a jet engine, was Coanda-1910, built and driven by Romanian inventor Henri Coandă in 1910. This aircraft engine used a piston jet engine. Unfortunately, this plane crashed at its first and final demonstrations.