Conducted 06/17/2012 -
Preparation for the third flight began with an annual condition inspection. While we had planned and conducted a complete condition inspection following first flight, it wasn't in the plan for after the second. But being we were going to need one by the end of the July anyway, and it had been so long between 1st and 2nd flights, it seemed a prudent thing to do. The days following second flight were forecasted to be stormy, and we had planned on finishing up the build of the wheel pants, so it was a good opportunity to spend some time at our home away from home. Some people enjoy relaxing at a cabin by the lake, we enjoy hangin' at the hanger.
The first thing we had found in our post flight 2 inspection was that the rigid stainless prop governor line was leaking at the fitting on the crank snout. We had replaced this line with stainless after discovering that the one that came with our engine was aluminum. The stainless doesn't flare very easy, and our flaring tool likely didn't create a perfect 37deg flare. We decided to use teflon lined flexible stainless steel hose for this line instead. The ends are easy to assemble and the hose is rated to 2500psi and 500 degrees, more than sufficient for this purpose. After installing and securing the new line we proceeded with the rest of the condition inspection.
All was looking good, no loose bolts/fittings/etc. The delamination 'tap test', while noisy, indicated no areas of delamination. Everything was checking out well. The last thing we conducted was the compression test. At first the readings were a little concerning. While not 'unacceptable' per Lycoming standards, they were about 5-7psi lower than the tests conducted just months earlier. Then, as we removed the tester from the third cylinder, the rubber o-ring around the compression tester fitting snapped. It was rather hard and brittle. Apparently not such a good quality rubber, if it deteriorated that badly in under a year (it was new in June of 2011). The bigger problem in our minds was that we were forecasted to have ok conditions for flight testing the following morning, and it was now 9:15pm. Where we were going to find an o-ring at this hour? There was a hardware store between the hangar and our house, but as luck would have it, it was closed as we drove by. Back in Monticello, the only stores open with any sort of hardware were going to be Home Depot, Target, and Walmart. Home Depot was probably our best bet, so with only 10 minutes until close, we scoured the 'o-ring selection', which consisted of a package of assorted o-rings. It looked like it contained a couple that might work, and much to our delight we found one of them did indeed fit the compression tester. We went to bed the evening of the 16th with intentions on being at the airport at 5am the following morning to complete the compression test and get the plane back up for flight test #3. Yeah....
At 7am we finally rolled out of bed, still tired from 2 late nights working on the plane. With a little coffee coercion we went back to the hangar to finish our condition inspection. We put the compression tester in the #4 cylinder and found that it was about 5psi higher than the other 3. Hmmm...On a hunch we retested the others. Yup, those readings were back up to where we expected them too. That was comforting.
We put the cowlings back
in place and proceeded to preflight the plane. Everything looked good, so
John got strapped in and Christine went over Mark Priglmeier's hangar so the two
of them could act as spotters for the flight. Below is John's flight
Things started off with a minor issue in that I forgot the 'good' battery for my laptop. This meant I would need to use a power inverter to run the laptop for the duration of the flight. It wasn't the end of the world, but I did mean that I would wait until my taxiing to fire up the laptop and begin datalogging. I know better than to do this on the move so after pressing the power button I taxied and did my run up before once again turning to the laptop to log in and start the software. For some unknown reason the usb to serial adapter that my GPS was connected to decided to change com ports on this particular bootup. I didn't want to waste even more time opening device manager and determining what com port it was now emulating, so I elected to take off without logging the GPS data.
As I taxied onto 13 I notice the oil temp was about 5 degrees warmer than my take off on the last flight. I was at 190 degrees vs 185 the previous flight. Not a much higher, despite being concerned about the extended taxi time to deal with the laptop. On the previous flight I brought the gear up and the prop back to 2300 about 500feet. Then I climbed to 5000 feet at about 125-130kts, and the oil temps slowly climbed to about 212. On this flight I also brought up the gear and brought the prop back to 2300 at 500 feet, but I can't really recall my climbout speed, and the lack of the gps data isn't helping my analysis. I do recall passing 2500 feet at in excess of 160Kts IAS, so up to that point I had kept the climb pretty shallow. I steepened the climb up to slow the plane down, and when I returned my attention to the engine monitor noticed the temps were at 220. I leveled off at 5k again with the oil temp at about 225, and brought the throttle back to about 16", same as the previous flight. The oil temp dropped to about 220-221 for a bit, so I thought all was on it's way to OK. Then they started climbing again, so I reduced throttle down to 15", and still they continued to climb. At 227 I decided something wasn't right, I throttled back to idle and informed my ground crew and tower I was descending back down to the pattern.
Temps came down to about 196 in the descent and landing before climbing back up to 221 on the taxi back to the hangar.
I shut down the plane and
proceeded to check to see if I had at least solved the leaking prop governor
line. It was dry, so at least one success. Next we need to figure
out these high oil temps.
Videos from both the ground, and from the plane (only slightly better than last time) are below:
Sorry, no pics this time...