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Flap actuator

rondawes

Well Known Member
This is about my RV-7A. I'm not the builder.

On a flight Saturday upon putting the flaps down for landing, the flap actuator disassembled itself. The flaps came up and I made a no flap landing.

See photo. The jam nut was not down that far when I opened it up. I moved it down when examining the unit.

Do I just screw the threaded rod back into the actuator and tighten the jam nut? In the drawings I have and the instructions, they indicate that there should be a safety wire from the lower end of the actuator to around the bolt. But in other photos on this site of flap actuators, I've not seen safety wires. So I'm a bit confused as to the proper way to reassemble this. Thanks.
 

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Be careful

Be careful drilling the little hole for the safety wire. I wasn't careful enough and ended up with the hole emerging too far up the actuator casing and now there is a path for grease to leak from it.

I haven't yet figured out what to do - it seems impossible to buy a new actuator without buying the whole flap motor assembly, so I will probably try to epoxy the hole closed. I'm anticipating it won't be easy to get the epoxy to stick given the presence of grease and the difficulty of cleaning it out of the hole. Suggestions welcome!
 
Turned out that I was somewhat lucky. There was a hole already drilled in the actuator for safety wire. There just wasn't a wire. I got it all back together and wired. Thanks for the help!
 
Ron,

Lucky you. Even though it seems like a simple operation I had a hard time drilling that hole.

Good to practice those no flap landings I guess. :D
 
Be sure to use the heavier .040 safety wire. I inspected an RV that had the thinner .032 wire and it had cracked.
 
Be careful drilling the little hole for the safety wire. I wasn't careful enough and ended up with the hole emerging too far up the actuator casing and now there is a path for grease to leak from it.

I haven't yet figured out what to do - it seems impossible to buy a new actuator without buying the whole flap motor assembly, so I will probably try to epoxy the hole closed. I'm anticipating it won't be easy to get the epoxy to stick given the presence of grease and the difficulty of cleaning it out of the hole. Suggestions welcome!

The same thing happened to me, I used JB weld to fix it, if I remember correctly, I think I disassembled it to clean it.
 
As I said, I was lucky that the hole was drilled in mine, just no saftety wire, which is puzzling. But if yours is not drilled, would this be feasible:

Since in normal operation the shaft does not retract fully into the actuator tube, would an alternative be to put an adel or hose clamp on the end of the shaft and then safety wire that to the lower bolt or flap arm weldment?
 
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