|November 17, 2006||HOME|
I started back to real airplane building by inspecting everything I had done so far. One thing jumped to mind, a little concern about the autopilot pitch servo and its attachment to the elevator bellcrank. There is about 1/4 inch clearance between the bolt end and a vertical brace. Were the nut to back off, could it bind the elevator control blocking down pitch? Another builder sent me an email on this about a year ago. I have decided not to decide what to do yet. I could simply use a an drilled bolt to take a cotter pin....
I also thought it would be a good idea to look into service bulletins that may have been issued by Vans over the last couple years while I was out of the building game. SB 06-2-23 calls for safety wire on the fuel pickup. I don't think there has ever been a problem when the fittings were properly torqued, but it is a safety bulletin and a good idea as well so I drilled the pickup fitting (actually, I faked the picture here. I backed the nut off before drilling) on each side at an angle that didn't disturb the threads. I was worried about it, but it proved quite easy to do.
Next, I drilled the anti-rotation bracket. The service bulletin suggests just wrapping the safety wire around the fitting, but I prefer to have a something to loop the wire through.
The easy part, twist the wire, wrap it around the fitting (tensioning it in the tightening direction, of course), run the wire through the anchor hole, twist it off and clip it.
The finished product provides more security than needed, but it is a reasonable extra precaution.