Jump to content

Engine throttle creep during high power setting


Hangman
 Share

Recommended Posts

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

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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

Link to comment
Share on other sites

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?

Link to comment
Share on other sites

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?

Link to comment
Share on other sites

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

Link to comment
Share on other sites

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

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...