EMPENNAGE MOUNTING AND RIGGING - SEPTEMBER, 2003

 

Sep 7 - Assemble, install, and adjust F-790 aft elevator pushrod.  There is a slight misalignment of the elevators.  After everything is in place and bolt tightened to fasten the F-790 aft elevator pushrod to the elevator horns, the LT elevator is 1 degree higher than the RT.  This translates to approximately 1/16" difference at the fwd end of the elevator counterweight arm.  Grrrr!  When I laid out the elevators to the H-stab on the bench and made the holes in the horns, I was very careful to get the alignment perfect.  Now, it's off a bit somehow when it's all assembled.  By pushing down on the LT elevator as I tightened the bolt, I got the difference to decrease to 0.7 degrees.  I will need to ask Van's about this.  Also, the plans say the F-790 aft elevator pushrod aft bolt is supposed to be an AN3-10A.  A -10 isn't even close; it needs to be about a -14.  Wrote Van's about it.  :Then left project and went flying.  2.5 hr + 3.0 doc

  This is partway through drilling and clecoing the F-790 aft elevator pushrod ends.  I did the holes in 3/32", then enlarged to 1/8".  The red marks make sure I get the end back in the same tubing end and lined up with the same holes.

 

  This shows the F-790 aft elevator pushrod installed.

Sep 17 - This is what Gus at Van's said about the elevator misalignment:

If the misalignment is only 1/16" I would leave it as is. Don't elongate the pushrod bolt hole or misalign the bearings. You could rivet a doubler to the horn or weld up the hole and redrill but it's not necessary for flight safety. I presume you are not relying on the c'weight arms to align the elevators. They may well be off slightly even though the elevator surfaces are correctly aligned.

And this is what he said about the F-790 aft elevator pushrod aft bolt:

The distance between the horns does vary a bit, probably it should say "use appropriate bolt length" rather than specify it. Use a spacer if you need more than 3 washers per side. A stack of washers can shift against one another so a spacer is better.

So, I'll be moving along on this as soon as I get home.

Sep 19 - Put 4 BSPQ-5-4 5/32" pop rivets into H-stab that didn't get put in when I was at Alexander Technical Center.  Removed elevators and H-stab from fuselage.  1.5 hr

  This shows where the H-stab rib meets the rear spar, and where a couple SBPQ 5-4 5/32" pop rivets get installed.  One pair outboard of outboard elevator hinge brackets on each side.

Sep 23 - Made (2) 0.255" long aluminum spacers from tubing to replace 4 washers where F-790 aft elevator pushrod fastens to elevator horns.  0.5 hr

That's about it for now on mounting the empennage.  Removed all empennage parts and returned to FUSELAGE

AUGUST, 2009 UPDATE:  after wasting over four years screwing with the Eggenfellner "complete FWF package", I am mounting the empennage for the last time.   Details here.

 

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