The jet engine marks the current gold standard in aviation. Yet few are aware of the immense evolution the jet engine has undergone over the last 80 years in terms of efficiency, durability, and reliability. It is a true testament to human ingenuity, one that is worth reviewing.
While early jet engines were developed for use in fighter planes as early as 1939, they were fuel guzzlers with little payoff in the way of speed. It wasn’t until 1948 when American engine builders Pratt and Whitney combined two engines into a single larger engine with two compressors, each drawing fuel from its own turbine, that the jet engine became a viable option for commercial aviation. Since then, engine builders have made rapid improvements upon the initial design. One major development of note is the transition from the early “straight-jet” model, in which air passed linearly through the engine, to the “bypass” model, which directs airflow around a central propulsor – thereby reducing noise and maximizing fuel efficiency.
Behind each of these improvements lies a complex pathway of design, building, and testing in accordance with rigorous compliance standards to ensure safety. The design process of a new engine takes approximately ten years from start to finish! Once the initial design has been completed, each component of the engine undergoes systematic analysis. Next, a preliminary prototype is assembled and subjected to an array of extreme force tests and operational scenarios. Upon successfully passing this battery of tests, the engine receives an airworthiness certificate and is eligible for installation in commercial aircraft.
In keeping with the intensity of the development and certification process, modern commercial aircraft can remain in operation for up to 25 years, some even longer depending on the type of jet engine installed. Moreover, the reliability of jet engines has vastly improved. Early jet engines typically allowed for around 2,000 flight hours before requiring a complete overhaul, but today’s jet engines regularly reach 20,000-25,000 flight hours between overhauls.