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View Full Version : Time to replace old Warner Electric trim actuator?



SWeidemann
08-19-2014, 07:09 PM
I'm going over everything on my third-hand Kitfox Model 5 Vixen & making a list of things to replace or improve.

Any opinions about whether I should replace my well-used horizontal trim actuator and motor? It is probably the original Warner S12 17A8-04 from when the plane was built (2003) and could have 1600 hours on it. Should I trust this?

Thanks much,

Skot

Vixen N24V

kitfox2009
08-20-2014, 09:00 PM
Hi Skot
I have a 1999 Vixen and at 120 hours replaced the trim jackscrew because it jammed in the full down position and the motor burned out .The a/c was still flyable but required heavy control inputs.
The original owner/builder replaced the rocker switch with toggle switch and it stuck in the down position.


Have over 500 hours with no issues.

Cheers
Don

Jerrytex
12-20-2018, 11:25 AM
Working on my KF 5 kit from the 90's. It has the Warner trim actuator. It's brand new sealed in the box. I am sure there is a newer style now but curious to know what if any problems were associated with the older trim actuators? Any reasonable reason I shouldn't use the one I have? I hate to buy a new one to replace a "new" one. I did see a thread about a making a bracket in case the casting broke. That would be an easy, worth while retrofit.

SWeidemann
12-20-2018, 02:26 PM
Jerry,

In my third hand Kitfox Vixen, I gladly replaced the old Warner unit with the different currently available electric trim unit (bought from the Kitfox factory), in the interest of safety. Years ago, a local Kitfox owner had a significant crash landing directly related to the failure of the casting on the Warner unit. In his current Kitfox 6 he has converted the elevator trim to a trim tab system operated by cables instead. The new model electric trim jack screw I have came with an added strapped-on bracket that will keep control of gross pitch changes in the unlikely event of a casting failure. I’m sure you can (or will) find out more about it from other KF owners.


Skot

Jerrytex
12-21-2018, 07:44 AM
So it's a breakage concern more than anything? I think if I decide to use it, I'll construct the safety bracket mentioned in another post. Might as well get whatever use out of it as I can if it can safely be done.

SWeidemann
12-21-2018, 08:17 AM
Yes, if you can fabricate a redundant add-on gadget that will keep everything together if your jack screw housing fails, great. Maybe a call to John & Debra to see if they have such a part, without having to replace a Warner with no time on it. Mine (Warner) was working fine & doing its job but I just didn’t trust it (after talking to my friend who crash landed because of the broken part).

Be safe. Skot

DesertFox4
12-21-2018, 10:09 AM
Kitfox Aircraft has the reinforcement bracket kit for the jack screws. 208-337-5111

Maverick
01-05-2019, 01:53 PM
When I bought my current KF5 project, the trim jack screw was one of the parts missing so I bought the latest one that Kitfox is now using along with the factory safety kit. I did not think to ask about what amp fuse to use for it though. Does anyone have what the max amp on the trim motor would be?

efwd
01-05-2019, 04:53 PM
John McBean told me it was a 7amp trim motor. Then I got to buy the Safety Trim Booster to get my auto pilot to be able to drive that motor for trim.

PapuaPilot
01-05-2019, 05:35 PM
I used a 7.5 amp circuit breaker for mine.

jrevens
01-05-2019, 06:16 PM
I used 7.5 A also.

jonstark
01-06-2019, 07:31 AM
Not familiar with the part but interested to know which end of the actuator fails. Upper or lower? A friend getting an old project back into the air is gonna want to know. Pix?

Jon

bumsteer
01-06-2019, 12:23 PM
Jon

Read Service Letter #54 on the Kitfox site (under Tech FAQ). It should give you the info you want.

Rick