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After my fourth visit from the FAA (all trivial paper-work issues), things now seem to have settled down, and each flight seems more "normal" and less of a test.

After reducing the horizontal stabilizer spacers from 5/8" to 1/2" (16  cm to 12 cm) and very slightly tweaking the left aileron tab, N28Bu now flies straight and level with my hands and feet off the controls.

During the testing I think I have discovered the phenomenon of "biplane relativity." Each flight, I take off and fly around the airport testing trim, power settings, and balance. I fly for 45 minutes or so. When I land, however, I find that for the people on the ground, only 15 minutes have passed, and the Hobbs meter has advanced by the same amount. Something to do with the Swiss paint, the clock tower in Bern, and Albert Einstein, I suppose.

I ran the engine for 30 minutes with the cowl off this morning, trying to find the source of the small oil leak. I found nothing. Not one drip, so I put it all back together. One of my airport friends told me there was a cook-out at Marysville, an airport only ten miles away and, coincidentally, the official center of my FAA assigned test area. I flew over and in one flight made my first grass landing, my first cross-country flight, and my first fly-in. It felt great! It really feels like a Jungmann :)

At this time of year in Ohio, the entire state looks like one big airfield. The crops have just been harvested, but the fields not yet plowed for the next season --perfect for test flying!

When I arrived at Marysville, there was oil on the belly again but not a drop under the cowling. The engine was clean and dry as before, and the oil dip-stick showed no significant drop in oil level.

I cleaned it up, checked everything again, and flew home. It was when I got back that I discovered the problem. The oil tank breather fitting is  too close to the oil return line from the engine. At high power settings, the oil is returned to the tank with such force that it splashes and sprays the oil into the vent line, and hence over-board. Should be easy enough to fix. I'll make some sort of baffle to prevent oil spraying into the vent.

I was able to spend some time talking to Joe Krybus and comparing RPM, manifold pressure, air speed etc. My engine and propeller performance seems to be exactly in line with Joe's, so I am relieved that my engine overhaul must not have been too bad.

I will probably continue flying during the brief evenings after work this week, then I plan to re-weigh the aircraft. The weights I measured would indicate that N28Bu is very slightly tail heavy, but it flys like it is very slightly nose heavy. It is only a slight discrepancy and well within normal limits, but I would like to weigh it in flight condition (me in the cockpit) and see how it looks.

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