SR HNA-HNA-23-2310-02B
近期一线工作中反映,在AMM手册中,涉及慢车渗漏检查、慢车系统测试等程序中,在步骤中有发动机关车后仍需再做一个干冷转2分钟的要求,在试车手册中未体现,在其他机型上也少见。
经核实,在LEAP-1B正常发动机关车程序中并无此步骤要求,之所以会在某些试车程序的步骤中有此要求,是因为在这些程序中,当发动机关车后,后续还紧跟有打开包皮接近检查或进行其它相关工作的步骤,因此在关车后增加2分钟干冷转,是为了对发动机进行快速冷却,以便后续工作开展。
CFM confirms Hainan Airlines understanding iscorrect. The purpose of dry motoring after shutdown in the referenced AMM tasks is to cool down the engine to make it accessible for maintenance personnel. This is a standard process for maintenance tasks which differ from anormal engine shutdown.