That, Could be dangerous to your health. Limiting the down elevator travel defines the safe aft CG limit. IF you are in a full stall while at your aft CG limit, it could be possible to have inadequate down elevator to break the stall. Limiting down elevator travel reduces elevator authority in stall recovery. BAD. Limiting up elevator travel reduces the ability to achieve a high enough angle of attack to get into a full stall, Safer.
Working on rigging my elevator travel today. I have about 1/2 the down travel that the TCDS call out for.
The PO added the silver stop you can see in the picture. I don't see it in the parts manual. I 'm guessing it's part of an STC. Anyone recognize it?
View attachment 61270
There are supposed to be two sets of stops (in all planes). One at the control end of the system and the other at the surface itself. The one at the surface is supposed to be the limiting stop. With a small amount of clearance at the control end to account for slop in the system. There is an FAR/CAR covering this which I do not recall. Long ago memory from A&P school.The travel stop for a PA-12 is located below the rear stick. This part is often removed at rebuild and forgotten.
That, Could be dangerous to your health. Limiting the down elevator travel defines the safe aft CG limit.
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Both question marks would be answered 'yes'.
It's interesting that the TCDS specified elevator travels are somewhat different between PA-12 and PA-18. -12 is 27 deg up and 32 down. -18 is 25 up and 15 down (double check me).
I rigged my -12 in accordance with the -12 spec, using -18 surfaces. No adverse characteristics.
With all the information I've gotten here and the facebook PA-12 group I went back to the plane and looked things over. I believe I understand why the bump stop was added. The PO installed a poorly conceived booster seat to the plane at some point. It limited the control throw quite a bit. The stop was added to keep the stick from hitting the seat.
Anyway, I removed the booster seat and the stop and now it is behaving as expected. I will need to adjust the stick position to center the stick in the available space and I should be good.
Thanks for all the help.
With all the information I've gotten here and the facebook PA-12 group I went back to the plane and looked things over. I believe I understand why the bump stop was added. The PO installed a poorly conceived booster seat to the plane at some point. It limited the control throw quite a bit. The stop was added to keep the stick from hitting the seat.
Anyway, I removed the booster seat and the stop and now it is behaving as expected. I will need to adjust the stick position to center the stick in the available space and I should be good.
Thanks for all the help.