Van's RV-9A in Aurora

The Big Picture

The Big Picture
Flying! 8/28/2011

Saturday, October 13, 2012

Haven't flown much in the month since the annual and trailing edge work was finished. Weather has been kind of crummy, such as today, which explains why I'm typing this in instead of returning from somewhere.
I did take up a couple of passengers, Brenda and Debbie.

Flew down to Galveston and visited the flight museum. Moody Gardens is right at the airport, so this is a possible destination with Lynne.

Finally, I flew out of Lakeway at dusk one evening to re-establish night currency. I flew a VFR ILS 13 at San Marcos, then a landing and takeoff in Junction, a landing and takeoff in Kerrville, and two landings and a takeoff in Fredricksburg. It was a perfect evening, the plane was flying on polished rails.

Leaving San Marcos, once established at 4500 feet I looked up and saw a V of birds about 500 feet higher. Another 10 minutes and it would be too dark to see them. That's right, large migrating birds at 5000 feet, at night! October is good time of year to fly, but there are risks.

One other item to add - the autopilot saga. The A/P pitch axis was acting up on the way home from Oshkosh. I removed the controller and sent it in, when I got it back it was completely refurbished. But it didn't fix the problem. I spent some time verifying the pitch servo cable. Perfectly fine. So out came the pitch servo and off it went to Arkansas to True Trak. They refurbised it (the amplifier had failed) and I got it back and installed on September 18. I'm happy to report that the autopilot now works perfectly. And it's brand new!

Right wingtip trailing edge

I finally conjured the nerve to break up a good airplane and split the right wingtip trailing edge.  With the trailing edge split and the rib removed, I could manipulate the structure as required to get it to line up nicely with the ailerons. 

Of course a prerequisite to this work was carefully adjusting the ailerons during the annual inspection using the jigs specified by Van's.  I measured and checked three times, so I'm confident this part is right.

After splitting the trailing edge, I mixed up some structural epoxy and flox and clamped the trailing edge in place, with a straight edge to make sure it all lines up properly.

After drying, I had a slight concavity, but the trailing edge is nicely lined up.  Next I match drilled the new rib and riveted in back in. Time to go test it out.

I'm typing this up about a month after doing the work, and I was very eager to make the test flight, and then very disappointed when it had absolutely no effect.  Double Drats!  I moped around for a couple of days, re-read the Van's heavy wing write up.  The last step of their analysis is, if all else fails, add a trim wedge.  So I  made up a styrofoam trim wedge to try out.

I used 3M brand speed tape (well OK, duct tape) and stuck the trim wedge to the bottom of the right aileron.  I had tried a trim wedge back in phase one, but it was not big enough.  This one apparently is - it completely solved the problem.  I tried a slightly smaller wedge, but went back to the first one.  Finally Cav flies hands off true, and the aileron trim is actually usefull for trimming out uneven loading.

Best of all, the trim wedge does not affect speed at all. I was afraid that a built in aileron deflection would add drag, but as near as I can tell, it stays pretty close to lined up with the trailing edge in flight, and didn't slow me down a bit.