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Prop Gov Return Spring Issue

Got my CS propeller all rigged up. Having a strange issue with the prop control lever. It moves freely for about half its range of motion. About halfway back toward the coarse/high pitch position it starts to engages the return spring on the governor. This results in the lever springing forward to the mid-range point once it is released. I've never seen this on a prop control before so it seems like its not designed to operate that way. I'm not really sure what to adjust to fix it. I'm also not sure what the purpose of the return spring is and Hatzell's governor manuals are scant.

Any ideas?
 
I installed a throttle quadrant on my RV-14A and discovered the prop governor spring was strong enough to cause the prop lever to creep unless the friction lock was engaged. I spoke with Hartzell and they indicated the aerobatic community had discovered this issue and they could provide a weaker spring. Problem solved. Turns out, this issue was a primary reason a throttle quadrant was not offered as an option for the 14 as it is for the 10. An easy solution, however, to keep an old Piper pilot from having to learn to use the push-me-pull-me vernier controls. :rolleyes:
 
Is this an S series governor? When set up properly, the return spring should be applying resistance to ANY movement of the governor arm off the fine pitch RPM stop. I believe it is set up this way so that any breakage of the cable or components will put the prop in fine pitch, as well as to account for slop in the cable assembly and maintain a precise RPM. It is likely that someone took the arm off and allowed the piece below it (the circular steel piece with the arm that catches the return spring) to come off and didn't not re-install it properly. There is a special procedure to get it back on properly and with the correct spring tension.

Do you have the hartzell maintenance manual? It has the procedure for installing that piece that catches the spring. It is not hard to accomplish. It is not in the owners manual, as they don't expect folks to remove that part. Normally the arm can come off without removing the piece below it if care is taken.

Larry
 
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