Final Fly Off Fix Adventures

It's been a while since I posted. I made the switch to an Apple and am still figuring things out. In the meantime, a lot has happened.

The fly off was going on in an expedited fashion down at the factory following the repair to the nose following my unfortunate incident in April. No matter what, you have to expect some glitches and gremlins during the fly off. That's the whole point of the restricted flight test regime. Mine included a number of expected issues and some real puzzlers. I offer the descriptions of the problems and the fixes for the benefit of those who have the fly off period yet to come.

The first issue was a flutter in the rudders at higher speeds. This is easily fixed by shimming them out as set forth below.

Next, there were some rattles and squeaks which were tracked down and corrected. Don't ignore ANY unusual noises or control feel. For example, a clicking noise in one right aileron hinge turned out to be a loose nut on the bolt attaching the aileron torque tube to the bell crank. I tightened it and the noise stopped. If ignored, it would have worn the hole and created slop, or worse.

There were leaks and seeps in the hydraulic system. My A&P at home told me you can't really claim to understand your hydraulic system until you are soaked in red fluid and know what it tastes like. (Then again, he may mean me in particular).

2 weeks ago, John had flown off 20 hours and I went down to Sebastian on Wednesday night with the intention of flying off the last 20 hours on Thursday through Saturday, then flying home with John on Sunday. I ended up having a much more frustrating and much more exciting stay than anticipated.

The plane had been puzzling everyone because the faster it went the more up trim was required, until finally it ran out of available trim. This is the opposite of what is expected. You should have to add more and more nose down trim the faster you go. I don't like atypical problems or mysterious flying characteristics. We decided to see if a stronger trim force would work, on the theory that either the trim spring was weak or not getting enough travel. We added a stronger spring and a 1/2 inch spacer.

This is when the exciting part came along. First, the stronger spring and spacer didn't help at all. I could take it up to 190 knots indicated, but had to pull back pretty hard not to nose down. I then did a sloppy pattern and ended up too high on final. Just as I noticed this, my Aerocomposite prop stuck in cruise pitch. Now I was really high. Add power to go around, again with the prop stuck at cruise, and get a very anemic 100 fpm at full power. Then, during the go around, the down and locked lights flicker on and off. Is the gear down? Better cycle it, only when the gear is cycled, the pump won't stop and the breaker pops. Great.

Nervous landing, then the obvious decision that it can't fly again until all these issues are corrected. I am disappointed, but Duane's comment brings me around, "Don't hate it, fix it!"

He's absolutely right. I am in the best place in the world to deal with crazy issues like this. Honestly, this could have taken me months to fix at my little airport back home. Instead, I got them all sorted out in 2 days at the builders assistance center. I've laid out the problems and fixes below in the hope they help someone out.

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The gear light turned out to be a simple adjustment of the nose gear up microswitch arm.

The pitch issue turned out to be the real poser. Scott came up with the answer. There should be a substantial step down from the top of the trailing edge of the canard to the top of the leading edge of the elevator. Mine was flush, with a hair fine gap. It has been years since I built it, and I honestly can't recall if this was a mistake or me trying to finesse a perceived advantage by creating the fine gap.

What was happening is that the low pressure air on top of the canard was staying attached to the top of the elevator. The faster I went, the faster it pulled up on the elevator, forcing the nose down. The fix was to remove and reinstall the elevators at the proper height. This process involved me spending about 4 hours with an air saw, torch and vise grips carefully removing each hinge arm. Then, we added back some chord to the canard trailing edge and reinstalled the elevators.

Here's another "gotcha" you can avoid thanks to me again making the mistake first. I thoroughly sealed my carbon fiber elevators. John looked out at them at 12,000 feet and was shocked to see them ballooning. The lesson: make sure you put several holes in each end of each elevator to allow them to equalize pressure at altitude.



The first try at a pitch fix was a stiffer trim spring. They happened to be laying up a new batch at the time.
Here is what they look like when they are made. We cut and installed one about a third thicker than standard. It didn't solve the pitch problem as mentioned earlier, but I ended up liking the feel better anyway.

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These pictures are worth clicking on and studying. This repair is Scott Swing all the way.

When I got the fast build wings from the factory, the trailing edge of the rudder didn't match the trailing edge of the lower winglet at all. Well, no problem I thought, and I just filed down the wing where it met the rudder until it trailed in nicely. Wrong!

The lower winglet was installed wrong and I unloaded the rudder on the winglet by doing so. This caused the rudders to flutter above 150 knots. The fix was to add shims to the rudder. That worked fine- no flutter all the way up to 220 knots indicated. The problem then became the lower winglets again.

Scott simply slit the bottom and top of the trailing half of the winglet, heated and reglassed them. As you can see, they ended up just right with almost no new fill needed. I will add flox and one bid to the winglet side of the vertical gap between the winglet and rudder and replace the shim with flox and microbubbles and it will be ready for final paint.

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Here it is with the canard off and ready to repair. I was really tired. Scott Swing was kind enough to come back from home after I got all the hinge arms out and lay up a new trailing edge using I beams clamped to the canard as a guide. The next morning Scott reinstalled the hinge arms in the correct position. The whole fix took less than 24 hours- that would only happen at the factory!

I removed the prop for the propeller service to pick up. I also decided to fix that annoying dump valve seep. There was no puddle of fluid in the keel, but there was always a stripe of red hydraulic fluid from the screws in the belly for the nose gear cylinder all the way back to the cowl. I bought a new dump valve, then used a bottom tap to enable the right angle fittings to seat deeper in the valve body. I changed it out and it solved the problem.

Duane Swing and I walked the gold box for the gear retraction system over to Wayne Lanza. His shop is in the hangar right next to the Velocity Builder Assistance Center. He found that one of the relays inside was fried. He kindly replaced it at no cost and we remounted the gold box. Again, you can only get this kind of quick resolution at the factory.

At that point, I had solved all of the issues I could solve for the time being and I headed home to Pennsylvania.

The folks at Aerocomposites called several days later to update me. They had the blades and confirmed that they had been machined with the shanks substantially oversized. They had them machined to the correct size, returned to Palm Beach Propeller, reassembled and delivered back to Velocity at no cost to me. I have to say that, although I was initially angry that I had the problem, I was impressed with the way they stood behind their product. All of this was done in a week and a half at no cost to me.

I got the call I had been waiting for from John Abraham on last Saturday. All of the repairs worked! As he put it, "It feels like a whole different airplane". The canard revision solved the mystery pitch issue and the prop worked great. The cruise at both 5,000 and 9,000 feet was just over 200 knots TAS. Like I said, I'm happy with any number starting with a "2" for my cruise speed. It is still in rough primer and no bolt hole covers. I think I can get a few more knots, especially if I add one electronic ignition.

Now the best news. The plane is working great and the hours are flown off. John is going to fly it up here and give me some dual time this Saturday. Finally, my airplane is ready to play with!

The bad news, I'm still not sure I'll be experienced enough in only 3 weeks to fly into Oshkosh. I'm going to play it by ear and see how it goes.

More to come this airplane homecoming weekend.

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