Van's RV-9A in Aurora

The Big Picture

The Big Picture
Flying! 8/28/2011

Sunday, October 17, 2010

7.5 hrs, 31 rivets

That was a long day. Took care of a couple of critical path items.
People keep asking when the kit moves to the airport. I'm thinking it goes within a month after the panel is installed and working. After the panel is done, need to rivet the upper forward skin (the last big riveting task), attach the windscreen and glass it in, make the canopy skirt, and repair the wings. There are a few wing tasks, mostly with the wing tips that will be best done at the house.

So when does the panel start and end? I'm guessing on a month to do the panel. The design is done, just need to install and wire. Stein supplied much of the wiring harnesses, so I'm expecting it to go reasonbly fast once the mechanical install is done.

I'm itching to start on the panel. It should be fun. Lots of cool toys to play with. I wanted to get the cowling mostly done. I was expecting to get it fit, install milspec fasteners, and that would be that. Wrong. The cowling is more than just a cover for the engine. It's an integral part of the engine cooling and breathing systems. So to get the cowling done requires finishing the baffles (air dams that direct cooling air over the aircooled cylinders), and the filtered airbox which supplies clean air for the engine to breathe. These sound simple, but there's a bunch of details, and the quality of the work here directly affects the performance of the airplane. The baffles have to be correct to properly cool the engine with a mininmum of drag. Baffles can easily make a difference of 10 knots at the same power setting, and cab adversely affect climb performance if the engine overheats at full power and slower speeds. The airbox obviously needs to be efficient to provide enough air for the engine, but there a extra items such as carb heat that have to be installed.
So the "cowling" keeps dragging on. But I'm slowly getting it all knocked out. I think I have another two weeks to go on firewall-forward tasks, and then a few days of other cabin related tasks before starting the panel. Maybe I'll be ready to move around the first of the year.

Sand lower cowling inlet inside where filler applied last night. Fit airseal and retaining strap, countersink for #6 screws.

Start fitting Filtered Air Box. Set alignment of upper plate to cowling and drill to carb attach plate. Make filter retaining clips.
Trim filter to fit over accelerator pump. Use proseal to close up filter/pump gaps.

Continue finishing on the baffles. Rivet 4 aft blast tube flanges. Rivet forward ramp curves.

Checking horizontal position of FAB top plate. It's going to have to be bent up so that the forward edge of the plate is level with the top of the inlet.

Started fitting the filter to the airbox. Believe it or not, the plans tell you to cut up the filter like this.