Looking at the Boeing 737 MAX now, one can’t help but notice its large engines. Like other 737 variants, thesehave been given flattened bottoms to ensure they have sufficient ground clearance. But the 737 was not designed for such large engines. The aircraft was designed in the 1960s, drawing from the older Boeing 707 fuselage dimensions as a smaller and more versatile aircraft. It was originally designed for the comparatively small Pratt & Whitney JT8D-15A turbofan.