Van's RV-9A in Aurora

The Big Picture

The Big Picture
Flying! 8/28/2011

Saturday, July 24, 2010

Canopy at last!

5 hrs, 9 rivets
Took care of a few preliminary canopy tasks a while back, but today marked the beginning of trying to fit the canopy frame in earnest.

Started by priming the canopy slider rail spacer and then going for a bike ride. After lunch, riveted the slider rail together.

Then put the canopy frame into place. Read the instructions for the 4th time. The canopy is one of the most difficult tasks to do. It's hard to get right, it's expensive when you mess up, and there are numerous horror stories on Van's forums. Fortunately, there are also numerous posts about how builders have done their canopies.

For the record, I intend to depart from the plans just a bit and use a couple of techniques that have proven successful for others. First, I will use SikaFlex (like the glue that holds your car windshield on) to glue the canopy to the frame, instead of drilling lots of holes in the plexiglass and using pop rivets to secure it to the frame. Second, I intend to make a fiberglass skirt, rather than trying to fit the aluminum skirt called out in the plans. The plexiglass canopy is cut down to a bit smaller than the opening it covers, so the skirt is just a fairing that covers the rest, provides a smooth transition, and helps to seal out the moving air.

After spending about an hour checking various measurements, I decided to first attack the forward bow height. This requires trimming the lower end of the forward bow a bit to bring it down. The two sides were a bit different lengths, and trimming the ends brought it to the correct height and centered it up nicely to boot.

The left side bow is nearly perfect. The right required a bit of bending to match the longeron. I think it's the right shape, but the aft end is about 1/8" too far outboard. I think the fix for this will be to adjust the rear bow a bit, bending it in, which will bring the aft end of the side bow in.

But before I do that bending, I will drill the tracks to the decks, because after measuring a whole bunch of times and adjusting, I think they are in the optimum place. After that I will start drilling the rail in place because it also is just about right.

All in all, I think the frame requires very little work. The front bow isn't perfect, The left side is nearly perfect, the right side is a bit oversized. But I don't think I can improve it. A fiberglass transition will help cover up the flaw.