Abstract: In order to study the frequent failures of a series of aircraft: when the flaps are in the down
position，press the“Close”button， the flap retracts slowly， accompanied by the phenomenon of oil leakage in
the cold gas port of emergency valve．The principle of aircraft flap is analyzed， and the emergency valve was
tested by air pressure experiment and hydraulic pressure experiment．The test results show that the emergency
valve works well and there is no air leakage，oil leakage and oil seepage during the test．The cause of the failure
may be: the flaps are in the down position， do not press the “restore”button， press the “close”button
directly; the attachment has been used for a long time， the contact gap between the conical end of the piston
and the emergency valve port has become large， resulting in the oil seepage． The experimental pressure was
higher than normal working condition，so no seepage is observed during the test．The oil contains impurities that
sandwiched between the conical end and the cold air port，causing the gap between the two，leading to the oil
seepage．
张 鹏. 某型系列飞机应急活门故障分析及预防措施[J]. 吉林化工学院学报, 2018, 35(1): 71-75.
ZHANG Peng. Failure Analysis and Preventive Measures of Emergency Valve In a Certain Type of Aircraft. Journal of Jilin Institute of Chemical Technology, 2018, 35(1): 71-75.
