Sunday, August 07, 2011
I added another 1.6 hours today in the air.
Several tests were done. First was a temperature measurement of the avionics area during taxi, pre-flight and in flight. Next was a test of flap deployment and retraction. finally I measured time-to=climb and have first numbers for Vy.
The ambient temp was 82F during the test flight. During run-up and taxi the area near the Dynon reached upto 95F. Opening the air hatches reduced this closer to 91F. I may need to install a fan tied to the master bus in the area of the Dynon.
Climbing out to 4000 I explored slow flight some more. The force it takes to deploy the flaps above 60MPH is very high. Realistically you need to be lower than 55MPH, or even 50MPH. I found the flap deployment produced a strong nose down attitude, but ample authority was available in the elevators and ailerons.
With the flaps deployed I attempted slow flight at 40MPH. I may attempt slower flight later. An attempt was made to stall the plane with the flaps deployed, but once again the elevator does not have the authority to produce a high enough attitude to stall the plane.
The transponder was re-verified and flight-following was used during most of the test-flight.
Additionally I reversed the bend of the trailing edge to the elevator. Currently the bend is now about neutral. This helped reduce the amount of nose up trim required for cruise flight. I suspect reflexing the flaps slightly will be the final solution to not requiring too much nose up trim in cruise flight.
The rear locking pin on the pilot side works well, although the door is slightly harder to close.
I did several measurements for Vy. The initial winner for a 4000-5000' climb is 45MPH. The time for 45MPH was several seconds faster than 50MPH. I did attempt 40MPH and 35MPH. The nose attitude of 35MPH is amazing. The ground reference plane of the Dynon just goes out of view. The other runs were made at 70, 65, 60 and 55 MPH.
After landing I did find a small drip was coming from a fuel sampler fitting. After cleaning the area with a cloth and examining it, it looks like the drip is coming from the sampler's hole. I checked the tightness of the fitting and it is secure. Furthermore I pulled on the fitting to make sure that it was fully down and not stuck slightly up. I may need to drain the tank and replace the fitting.
The plane now has 5 hours in the air and 4 flights\takeoffs\landings.
According to the indicated fuel levels, 5 gallons were used in the 1.6 hours of flight. Fuel burn was at 3.1 gallons an hour.