Tri Pacer elevator rigging

[Steve Pierce]

Merged your thread with two others on the subject. Having recently rigged a few Pacers and Tri-Pacers and wonder what your cable tensions are?

[Planewrench]

Thanks Steve. Cable tensions were excessively tight. Also found that the elevator up cable (12 ft 2 in) is 2 inches longer than the elevator down cable (12 ft). Earlier in the thread, JohnW states that the upper cable should be shorter than the lower cable.
I don't have the CD w/ drawings & the customer wants the aircraft ASAP since he's moving out of a hangar that's scheduled to be torn down. Are these cables the appropriate length?
Thanks.

[Steve Pierce]

One cable is longer than the other. I will have to look at the drawing again.

[DrHook3960]

I just looked at my CD upper cable pn 40123-67 is 144 1/4" dn cable pn 40123-68 is 143 3/8" hope that helps

[Steve Pierce]

i remembered that one was longer than the other but could not remember which one. The last one I rigged had had new cables made and they were the wrong length and we couldn't get the deflections per the TCDS. Had to pull the cables and replace them.

[mdcf18]

I've been searching for answers and this thread comes close but not quite. I understand the elevator and Horz. stab rigging. The thing I'm concerned with is the trim interconnect cable to the elevator. The two cables, one top and one bottom run from the trim yoke,(rear side) to the elevator bell crank. Two new cables were fabricated and they are the correct length, one being longer than the other. The springs which attach the cables to the elevator are new, purchased from Univair. The PA22-20 we are restoring appears to have excessive tension on the cables. So tight that the control column becomes difficult to move at the extream ends of its travel. Which end of travel of the control column that become difficult to move seems to change when the trim is moved to it's extreme travel limits. Can someone tell me how much tension is supposed to be on those two cables, called bungee in the parts manual, and the associated springs?

Thanks in advance
Chuck

[Gilbert Pierce]

Changing the trim changes the tension on those bungee cables. The elevator to some degree follows the trim as you change it. It loosens one bungee and tightens the other.

If you have the trim set in the middle, the elevator is hard to move at the extreme up or down elevator. You won't land this airplane if you have not trimmed off the load unless you want a real workout pulling the yoke back.

Crank your trim about half way from the center towards nose up and then pull the elevator nose up and see if you haven't considerably lessened the load, tension, on the elevator.

I don't know what the tension on those bungee cables is but would guess it is upwards of 35 to 40 lbs minimum. you won't be able to pull any slack in the with your hand.

[Lownslow]

I am guessing you have a parts manual and have all the right parts in place. One check is to center the trim on the drum and the elevator should be relatively in line with the stabilizer. Like Gilbert said, the trim is your friend on approach to landing and relieving back pressure for roll-out.

Lou

[Allycat]

Hello All,

PA-22/20 Conversion

All measurements taken using digital inclinometer. Airplane leveled with plumb bob at door frame hole and cross member dimple.

I'm finding only 6 degrees (of the 7.5) of total travel of the horizontal stab, 1 +/- .5 up, 6.5 +/- .5 down. Yoke is installed correctly and runs full travel. With these numbers total travel of stab would only be off by .5 of a degree. This something anyone else has seen?

Also having difficulties with getting elevator to contact primary stops with stab at or near neutral. The stops are being contacted at either full up or down trim.

I think my next move is to check cable lengths.

Steve I was wondering how you determined the -67 and -68 cables apply to the PA-22 150 out of the six different sets of dash numbers listed in the 40123 drawing? Gotta be something simple I'm missing.

Thanks,
Allycat

[Steve Pierce]

Hello All,

PA-22/20 Conversion

All measurements taken using digital inclinometer. Airplane leveled with plumb bob at door frame hole and cross member dimple.

I'm finding only 6 degrees (of the 7.5) of total travel of the horizontal stab, 1 +/- .5 up, 6.5 +/- .5 down. Yoke is installed correctly and runs full travel. With these numbers total travel of stab would only be off by .5 of a degree. This something anyone else has seen?

Also having difficulties with getting elevator to contact primary stops with stab at or near neutral. The stops are being contacted at either full up or down trim.

I think my next move is to check cable lengths.

Steve I was wondering how you determined the -67 and -68 cables apply to the PA-22 150 out of the six different sets of dash numbers listed in the 40123 drawing? Gotta be something simple I'm missing.

Thanks,
Allycat

Figure 33 Item 30 and 31 in the parts manual.

I question if some of these airplanes meet the control surface deflections in the Type Certificate Data Sheet when they were new after a few I have checked rigging on.