Hangman Posted July 10, 2008 Share Posted July 10, 2008 Good day. We encountered a strange defect on the C130H during a recent ground run, after a left wing refit during a depot maintenance. #1 throttle crept slowly towards T/O after a couple of seconds when all throttles were set at 900degC. A thorough check has been carried out on the airframe to engine cable tension,rigging and signs of binding. The results come up to be good. There wasn\'t any sign of engine vibrations during the ground run. We had also replaced the engine control clutch at the \'horsecollar\', a FCU and a coordinator as a precautionary measure. However, the defect remained the same. Has anyone had any suggestions to this problems? Thanks and appreciate. :S Quote Link to comment Share on other sites More sharing options...
Steve1300 Posted July 10, 2008 Share Posted July 10, 2008 Nearly every time I have that problem, I end up replacing worn bushings in the gimble itself. There is a knee joint for the gimble that has bushings that will wear, but gets little attention as it is difficult to see. If those are worn, they will cause the throttle lever to creep. Quote Link to comment Share on other sites More sharing options...
casey Posted July 10, 2008 Share Posted July 10, 2008 We had a problem with a creeping throttle problem on a TDY. After we checked everything in the book and then some, we tried swapping the throttle quadrant friction washers around (I think that is what they are called, it was 15 years ago.) Believe it or not, it fixed it. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted July 10, 2008 Share Posted July 10, 2008 Agree with Steve1300, gimbal is most often the culprit. Also check cable tensioners at 245 bulkhead, and make sure all pulleys are moving freely. We had a condition cable jump recently - I believe a seized pully bearing in the horse collar was the culprit Quote Link to comment Share on other sites More sharing options...
Gmon Posted July 10, 2008 Share Posted July 10, 2008 All engine control rods should be inspected, bushings swapped for any play. If all rod ends have been inspected, whole gimble assembly has been swapped, and fuel control and coordinator changed, I would look outside the engine. I have seen springs within the throttle quadrant cause such a problem. Does the problem go away with the friction knob when it is tighten? Quote Link to comment Share on other sites More sharing options...
Parrot Posted July 10, 2008 Share Posted July 10, 2008 Did the engine follow throttle? Quote Link to comment Share on other sites More sharing options...
Hangman Posted July 11, 2008 Author Share Posted July 11, 2008 Hi, guys. The throttle lever stops to creep whenever the friction knob is tightened. The lever creeps every time when it\'s pushed at high power settings. The engine parameters did follow its throttle as it creeps. By the way, what\'s the friction washers in the quadrant? Quote Link to comment Share on other sites More sharing options...
SonnyJ Posted July 11, 2008 Share Posted July 11, 2008 The friction washer is made up of three wedge shape pieces that sit between the #2 and #3 throttle levers. The friction knob shaft runs thru the lower center wedge and the shaft floats in a notch on the top of the other two wedges. When you tighten the knob the wedges are pulled together and take up the play in between the components on the throttle shaft. Later models started putting a washer on the friction shaft where it rides on the throttle shaft to help eliminate the friction shaft from seizing. That and the brass shims in between each component that rides on the throttle shaft would wear out are the two most common problems with the throttle quadrant. Make sure your cable tension is equalized between the cables. That could contribute to your problem. Sonny Quote Link to comment Share on other sites More sharing options...
tinyclark Posted July 11, 2008 Share Posted July 11, 2008 Here\'s something I came up with to explain it to supervision(s). We just has a quadrant replaced here for one lever creeping. Well, it didn\'t really come out readable. I can e-mail it if anyone wants it. [img size=1063]http://herkybirds.com/images/fbfiles/images/friction_knob_101_smaller.jpg Quote Link to comment Share on other sites More sharing options...
EClark Posted July 11, 2008 Share Posted July 11, 2008 That\'s outstanding Tiny been 40 years since I saw that dia. Quote Link to comment Share on other sites More sharing options...
tinyclark Posted July 11, 2008 Share Posted July 11, 2008 Here\'s the blow up of the area on the left. Quote Link to comment Share on other sites More sharing options...
EClark Posted July 11, 2008 Share Posted July 11, 2008 Tiny if you click on the 1st dia. it will enlarge Quote Link to comment Share on other sites More sharing options...
casey Posted July 11, 2008 Share Posted July 11, 2008 Thanks for jumping in guys. You were able to provide a much better explination than me. It has been too long. Quote Link to comment Share on other sites More sharing options...
Hangman Posted July 12, 2008 Author Share Posted July 12, 2008 Thanks for all your precious experience sharings, mates. We had replaced the whole engine control pulley assembly with a brand new one, and change all bushings for that \'knee\' support link assembly which attached to the engine control pulley assembly. We went for the ground run and found that the symtom has actually improved, however the creep is still noticeable. The rate of creep has significantly slowed down. We hope we can eliminate this defect by looking into some defective quadrant components. Cheers. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted July 12, 2008 Share Posted July 12, 2008 No Problem. let us know what the final result is .... Quote Link to comment Share on other sites More sharing options...
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