munirabbasi Posted December 8, 2020 Share Posted December 8, 2020 Hello Herks Hydro Expertise! Retraction cycle Timing of Right landing ( B model aircraft) is exceeded from prescribe given time sec ie ,38 seconds with UT hydraulic system but when retracting the landing gear with AUX hydraulic system on ground timing is with in limit ie 17 second . We have replaced right side of landing gear, the flow regulator, controllable restrictor valve, one way restrictor, hydraulic motor ,gear box,landing brake lock and HI.Torque two speed valve but defect was repeated again and again in every sortie. any expert opinion Best Regards Munir Abbasi Home Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 8, 2020 Author Share Posted December 8, 2020 Just now, munirabbasi said: Hello Herks Hydro Expertise! Retraction cycle Timing of Right landing ( B model aircraft) is exceeded from prescribe given time sec ie ,38 seconds with UT hydraulic system but when retracting the landing gear with AUX hydraulic system on ground timing is with in limit ie 17 second . We have replaced right side of landing gear, the flow regulator, controllable restrictor valve, one way restrictor, hydraulic motor ,gear box,landing brake lock and HI.Torque two speed valve but defect was repeated again and again in every sortie. any expert opinion Best Regards Munir Abbasi Home Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
hehe Posted December 8, 2020 Share Posted December 8, 2020 When you say it is not passing timing checks in UTIL, what are you using as the source? Ground powered hydraulic test stand? The aux pump is very weak for flow so if you are passing timing checks with the aux pump, I would take a good look at your hydraulic test stand. What is the UTIL system pressure dropping to during gear travel? Quote Link to comment Share on other sites More sharing options...
hehe Posted December 8, 2020 Share Posted December 8, 2020 (edited) I just read that again and noticed you said in flight. Normally I would suspect engine pump or filters in the return system but since you are only having right side issues I would suspect mechanical issues that are only showing themselves in flight. Have you done free fall checks of that gear? Have you checked lubrication of MLG tracks, door linkage rigging, shoe rigging, ball screw/nut condition/wear, etc? Are you sure the gear is not mechanically binding in a way that is only showing itself in flight? Edited December 8, 2020 by hehe Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 9, 2020 Author Share Posted December 9, 2020 9 hours ago, hehe said: I just read that again and noticed you said in flight. Normally I would suspect engine pump or filters in the return system but since you are only having right side issues I would suspect mechanical issues that are only showing themselves in flight. Have you done free fall checks of that gear? Have you checked lubrication of MLG tracks, door linkage rigging, shoe rigging, ball screw/nut condition/wear, etc? Are you sure the gear is not mechanically binding in a way that is only showing itself in flight? Thanks For excellent Response Best Regards Munir Abbasi Home of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.