239、当液压系统 B 的发动机驱动泵压力低于正常时,液压动力转换组件系统为前缘襟翼和缝翼提供备用液压。
答案解析
解析：
相关知识点：
液压B泵压异常时组件供备用压
相关题目
1222、请注意,飞机的改装或修理工作必须由持照人员完成。
1221 、 Aircraft maintenance manual or section ， which includes at 1east thefo11owing D informationintroduction information that includes an explanation of the airplane＇s features and data to the extentnecessary for maintenance or preventive maintenance.
1220、对于拥有或操作非运营飞机的持照飞行员，可以在联邦航空法规 43 部的授权下对其飞机实施受限制的预防性维修。
1219、It has a single shaft and operates at a constant speed.
1218、This enables better thrust management and decreases fuel consumption.
1217、用大量肥皂水清洗窗户。
1216、This document shall specify，for a crack inspection, the minimum size crack expected to be discoveredor, if no minimum is defined, a statement to this effect.
1215、Controls in the flight compartment permit selection of temperature and flow rates.
1214、不要使用可能引起火花的测试设备。r
1213、Make sure that the temperature of the probe increased to more than 500℃。
