Finally the weather cleared, so I was able to fly today. We are now up to 17.6 hours. Today was the first flight with the permanent cooling air diverter installed in the cowl. It really evens out cylinders #3 and 4. The temperatures got hotter than when I was testing the foam/tape diverter, but I also was more aggressive with leaning. It will be interesting to see if this works on 90 or 100 degree days.
I did open the flight envelope a little bit. I went up to 8500 feet, the highest I have had the airplane thus far. It seems like no matter what altitude I use, my true airspeed settles out about 176 kts. During the descent I opened up the top end of the speed range to 190 KTS TAS. I did stick slaps and rudder kicks and there was no sign of flutter. So far so good on the top end.
I also did some work in slow flight. To this point we had only validated controllability down to 65 KTS IAS. I used the FAA AC 90-89A procedure to work towards the stall. Using 1/2 knot per second deceleration I decelerated from 65 KTS. Each knot decrease in speed I validated that maintaining the new airspeed required an increase in stick force (positive stick force gradient) and that I had positive pitch down authority. The plan was to validate down to stall or a minimum of 60 KTS. At 61 KTS, I got a pronounced increase in stick force and a buffet. I didn’t allow the canard to actually stall, but this was a very welcome sign of what so far looks to be a good margin between canard stall and main wing stall. Further testing will follow, but this was a very good first step in stall testing. For those of you that are interested this test was done at a calculated 1501 lbs and a CG location of 102.2.”
While I was out in the “play pen,” Greg rendezvoused with me, and we did some formation. It was very nice. The outside air temperature was 37 today, and I was very comfortable. It was smooth as could be.
With stall and controllability validated down to 61 KTS IAS, I decided to lower my approach speed to 75 KTS. My landing was the best I have had in the airplane yet, which isn’t surprising. Not carrying a ton of extra speed makes a huge difference. I think I can probably even reduce this speed to 70 KTS at 1500 lbs as I still had a significant float. I will work on learning what works best as time goes on, but after today, I feel like the airplane and I have learned more about each other.