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Flaps retraction issue

N427EF

Well Known Member
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On my last few flights I noticed that the last two or three degrees of flaps would not retract until sometime into the flight and not after repeatedly moving the
Flap switch up/neutral/up etc.
I have a TCW flap controller installed and as you can see in the picture, the mechanism relies on a notched rod that indexes the flap positions, 0 degrees, 3 degrees, 10 degrees and 40 degrees.
There is a considerable amount of rotational play on the rod end bearing due to torque generated in the linear actuator. Holding the rod end steady with my finger allows for normal flap retraction.
I cannot tell which part might have worn but the rod end bearing play (side to side) seems excessive and the cause of the issue.
Has anyone seen this problem with their flap actuator?
The rod end bearing could be replaced with one that has less side to side play since the linear actuator geometry does not appear to require a rod end bearing with so much play.
The clamp holding the indexer rod can be rotated and it may be the part that slipped after 800 hours of use? I am thinking of installing a couple of nylon bushings to keep the rod end from excessively rotating. However, that idea seems to defeat the purpose of a rod end bearing.
Any advice is appreciated.
 

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On my last few flights I noticed that the last two or three degrees of flaps would not retract until sometime into the flight and not after repeatedly moving the
Flap switch up/neutral/up etc.
I have a TCW flap controller installed and as you can see in the picture, the mechanism relies on a notched rod that indexes the flap positions, 0 degrees, 3 degrees, 10 degrees and 40 degrees.
There is a considerable amount of rotational play on the rod end bearing due to torque generated in the linear actuator. Holding the rod end steady with my finger allows for normal flap retraction.
I cannot tell which part might have worn but the rod end bearing play (side to side) seems excessive and the cause of the issue.
Has anyone seen this problem with their flap actuator?
The rod end bearing could be replaced with one that has less side to side play since the linear actuator geometry does not appear to require a rod end bearing with so much play.
The clamp holding the indexer rod can be rotated and it may be the part that slipped after 800 hours of use? I am thinking of installing a couple of nylon bushings to keep the rod end from excessively rotating. However, that idea seems to defeat the purpose of a rod end bearing.
Any advice is appreciated.
Guessing those notches in the rod allow a limit switch to open. If the flap tube rotates too far ccw in pic, that will change the angle of the notched rod and force the notches closer to the internal limit switch, possibly preventing it from opening and mess with the mechanicl logic of the system. With time, the tube rotates enough that the switch opens and you get the remainder of travel at that time. I would either replace the heim or fabricate a brace around the outer part of the heim that prevents most of its rotation.

Have never had your problem, but did take steps at install to insure the the notched rod was centered equidistant from the two furthest rotation points of the heim. I can see in your pic the the small notched rod holder is not centered relative to the heim center. The rod angle will grow much larger in one direction of heim movement than the other. Simply getting the notched rod dead parallel to the tube when the heim is centered may be enough to fix this.

Good luck with this.
 
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