Alon Control Column Installation


1. Carefully inspect the entire control column assembly to verify that it is properly assembled. Verify that all required cotter pins are installed. Verify that it can be operated easily by temporarily attaching a control wheel and shaft to the column and checking for excessive drag.

2. Reinstall the control column in the reverse of the order in which it was removed. I used AN174-10 close tolerance bolts to reattach the control column to the channels in the airframe. Be sure to install the proper washers, nuts and cotter pins.

3. After the control column is back in place and the control wheels have been reattached, use a straight edge such as a 2X4 board or piece of aluminum angle and attach it to the control wheels such that the control wheels are locked in the neutral (straight) position.

4. With the control wheels locked in the neutral position, adjust the turnbuckle and cable end fittings to the proper tension while keeping the center control shaft exactly centered. This can be measured and verified by using the aileron center stop tab as a reference. You want to end up with the control wheels dead level, and the center control shaft exactly centered, and the tension on the cables and chain correct. The service manual does not seem to indicate what the correct tension is. Basically you want the chain and cables adjusted so that you have little or no slop in the linkage, but you do not want it so tight that the cable, chain, sprocket shafts and bearings are overly stressed. Note that every adjustment to the turnbuckle or to the cable ends interacts with the whole system so that if one item is adjusted, it will probably be necessary to adjust the other items as well. After getting everything centered and adjusted where you want it, remove the straight edge from the control wheels and see if everything stayed the way it was. You may find that turning the control wheels loose causes them to both tip outboard or both tip inboard. If this happens, you’ll need to adjust some more. Just be sure that when you are done, the inner control shaft is exactly centered when the wheels are exactly centered.

5. Once this is done, the rigging procedure in the Alon Service Manual can be followed to finish rigging the airplane. Make sure that the control column turnbuckle is safety wired properly.

6. After the rigging is complete make a final inspection for missing nuts, bolts, cotter pins, safety wire, tools, trash, etc. Make sure that all bolts and nuts clear the structure while turning the controls over their full range of movement. Also verify that all stop bolts, jam nuts, etc have been properly adjusted and tightened.

7. When completely finished do a positive control check by having an assistant hold each control surface and apply resistance to the surface while the control wheel is turned in each direction. Verify that each control surface moves in the correct direction and that every movement looks, feels and sounds correct.

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Page last modified on January 14, 2011, at 02:05 PM