The CFM 56 on the 737 (NG or Classic) also has a flat bottom. E.g., [1] shows a 737-800 with an engine with a flat bottom, and [2] shows a 737-300 with an engin

The CFM 56 on the 737 (NG or Classic) also has a flat bottom. E.g., [1] shows a 737-800 with an engine with a flat bottom, and [2] shows a 737-300 with an engine with a flat bottom. [1] https://commons.wikimedia.org/wiki/File:CFM_56_Lauda_737.jpg https://commons.wikimedia.org/wiki/File:CFM_56_Lauda_737.jpg [2] https://commons.wikimedia.org/wiki/File:Classic_Colors_Southwest_Airlines_N648SW_Boeing_737-3H4_SJC.jpg https://commons.wikimedia.org/wiki/File:Classic_Colors_South...