Conducted 4/27/2013 –
The Big Push. On a day forecasted to be perfectly clear, with just 8 hours of testing to finish, we decided we would try our best to complete Phase one testing that day. Fitting 8 hours of flying into 14 hours of daylight might not seem like a tough task, but when those 8 hours are in ~1.5 hour chunks with reballasting and refueling in between, the task gets tougher. To accomplish this each of us had a significant part to play. John, as test pilot, was responsible for ensuring that each flight was conducted safely, and in accordance with the flight test plan. Christine was to coordinate the ground operations so that as soon as the plane landed any additional ballast needed for next flight was ready, and the line guys were ready to refuel the plane. Ella, was to take the responsibility of maintaining radio communication with John when Christine was not able to. Ella would then relay messages if needed. For the most part, the day went like clockwork, and it ended in celebration.
John’s flight report to the Cozy list is below:
“The weather held perfect for all day Saturday, and we were back at the airport at 6:30am. We had already re-ballasted the plane for the next test before leaving the night before, so it was just a matter of pushing the plane out, preflighting, and getting right back to work with climb/descent testing. After each test, I would land, re-ballast (which sometimes required more fuel), then head back up for another round. I figured if I didn’t waste time, I might be able to make it through the rest of the tests by the time the sun set.
As it turned out, Summer fell on a Saturday here in Minnesota. We went from 30-40s all April to a high of 74 on Saturday. While, it was very nice to finally be flying without a parka again, it brought back one other little issue…Ground cooling. As the temps warmed up in the afternoon, the 30 minutes between landing and the next take off were not enough to allow the oil temps to drop sufficiently. My last flight before stopping for lunch, the oil temp was 179F at start up and 200F at take off. I only climbed to 4K’ MSL (3K’ AGL) on the initial climb, but the oil temp rose to 235F in that short 2 minutes. As I conducted the next climb tests I did learn a bit of useful information without even looking at the EFIS logs. My normal climb out is 120Kts, but the oil temps don’t seem to rise a whole lot faster if I climb at 85kts. The plane climbs much faster at 85Kts though, so I’m able to get to a given altitude with lower oil temps. The downside is that I can’t see anything ahead of me. The CHTs didn’t seem to differ much on the climb speed either. They were only slightly higher at increased climb angles. My hottest cylinder (#2) never exceeded 420F at any point in the testing, the others never exceeded 380F. In cruise #2 runs about 365F compared to the 280-290F of the others, so I apparently have a little airflow balancing to do yet.
After completing the climb and descent testing at the various weight and CG locations, The last test to conduct was flutter testing. Initially that test didn’t scare me. I knew my control surfaces were balanced. I checked them only a few dozen times during the build. I also knew there was no slop in the controls. If anything my controls were a little stiff in pitch due to the pitch trim system. But in discussion with various other folks I became more and more worried about it. My DAR offered to lend me his parachute, and I decided that would make me feel better. At least if I wore a chute, I would likely not need it, so the superstitious side of me said to wear one.
When I went through the flutter testing in the sim, the realization of what it would feel like was clearly not present. I conducted the tests between 7500’ and 8500’ MSL, all the way to 200Kts IAS. Smacking the stick or jabbing the rudder at those speeds unsettles both the plane AND my stomach. Pitch was probably the worst. I usually LOVE roller coasters, but having my stomach jump to my throat or my butt is NOT a feeling I enjoyed, however brief, while flying my plane.
The good news is that there was no flutter at any speed. Once the flutter testing was complete I looked at the flight timer, I was less than .2 hours from the 40 hour mark. I flipped on some music, and just cruised around bit letting the realization set in that when I landed the plane I would be one log book entry away from the adventure of building an airplane giving birth to many, many more adventures.”
