who makes the jet engines for the 737
Boeing 737 Engines on the 737 Classic series (−300, −400, −500) and Next-Generation series (−600, −700, −800, −900) do not have circular inlets like most aircraft. The 737 Classic series featured CFM56 turbofan engines, which yielded significant gains in fuel economy and a reduction in noise over the JT8D engines used on the −100 and −200, but also posed an engineering challenge given the low ground clearance of the 737. Boeing and engine supplier CFMI solved the problem by placing the engine ahead of (rather than below) the wing, and by moving engine accessories to the sides (rather than the bottom) of the engine pod, giving the 737 a distinctive non-circular air intake.[44]