The company also uses the 757 to test most of the  engines it produces, including the HTF series, TFE731, and TPE 331- powerplants that are used  in both military and corporate aircraft.

该公司还使用 757 测试其生产的大部分发动机，包括用于军用和公务机的 HTF 系列、TFE731 和 TPE 331 发动机。