The Boeing 737, a popular commercial aircraft, has seen nearly 12,000 units built since its introduction in 1967. Over the years, the aircraft has evolved through different variants powered by four main types of engines.
The Boeing 737 family is divided into four sub-families: Original, Classic, Next Generation (NG), and MAX. Each sub-family represents advancements in technology and design. The Original series includes the 737-100 and 737-200 models, with the latter being more successful in sales. This was followed by the Classic series in the 1980s, which included models such as the 737-300, -400, and -500. These models improved on capacity and range.
The Next Generation series emerged amid increasing competition from Airbus and consisted of models like the 737-600 to -900. It was succeeded by the MAX family in the mid-2010s, which features certified variants like MAX 8 and MAX 9.
Initially, Boeing used Pratt & Whitney JT8D engines for the Original series. These engines were known for their distinctive long and thin appearance. According to Pratt & Whitney, these engines have logged over 673 million flying hours.
For the Classic series, Boeing switched to CFM International’s CFM56-3 engines. “According to CFM International,” this engine is part of a family that powers various commercial and military aircraft. Its use resulted in increased efficiency and reduced noise pollution compared to its predecessor.
The NG series continued using CFM International engines but upgraded to the CFM56-7 model. This engine offered better fuel efficiency and power compared to earlier versions. CFM International notes that this combination became “the most popular engine-aircraft combination in commercial aviation history.”
Finally, for the MAX series, Boeing opted for a new design with CFM International’s LEAP-1B engine. Despite challenges such as a grounding period due to accidents involving MAX aircraft, Safran reports that LEAP-1B engines have already accumulated over 60 million flight hours across more than 160 operators globally.
