Jet engine

One of the most important developments in the long-term improvements in aviation safety was the jet engine. Between 1946 and 1958, the United States averaged three major plane accidents and 42 fatalities a year in accidents caused primarily by engine failures. Since the introduction of the passenger jet in the late 1950s, the number of crashes due to engine failure plummeted, as did the total number of plane accidents.
While traditional piston engines improved greatly through the 1930s and '40s, they did not offer satisfactory reliability. In fact, as power increased (an objective in developing military planes), reliable endurance tended to decrease. By the 1950s, the best piston engines available could only run 1,500 to 2,000 hours before they required overhauls.
All this changed with the jet engine. In 1958, National Airlines launched its jet service between New York and Miami. These early jet engines extended the "time between overhaul" (TBO) to 6,200 hours and then to 20,000 hours. Today, with proper maintenance, jet engines can perform up to 50,000 hours before a complete overhaul is needed.
The increased performance level of jet engines affects safety in a number of ways. Most obviously, the reliability of jet engines ensures that crashes due to engine failure are uncommon events. Jet engines also allow planes to fly longer and faster, enabling planes to travel to a different airport if their original destination proves unsafe for landing. Finally, powerful jet engines allow planes to fly above dangerous storms and turbulence.