 Directly behind the pilots is where the aircraft's flight engineers would be stationed, these engineers could directly access all six engines in-flight via compact walkways housed inside of the wings.Originally, the Laté 521 was intended to be powered by an arrangement of four Hispano-Suiza 18Sbr W-18 engines, derived from an existing racing engine; however, these engines would ultimately never become available.According, in their place, it was decided to adopt six Hispano-Suiza 12Ydrs, each capable of , for the first aircraft.