With the Sky Eye roughly set up and trimmed out, I was ready for some initial flight tests to get a feel for the airframe.
Being Tehachapi, it was pretty windy at about 10kts coming from the North. This is actually pretty calm for Tehachapi. Anyhow I bring this up because to my delight when I placed the model on the ground to get everything plugged in and checked, I discovered I could actually keep the wings level and the model resting squarely on it’s one wheel with just a little bit of wind. Those big ailerons are already coming in handy!
Unfortunately, as I said in my last post, the wheel binds up pretty badly when it has weight on it so taxiing was pretty ineffective. Would probably be possible with a real runway instead of the cul-de-sac I was using but this wheel is made for landing, not take-off.
I did this flight with a small 2200 mAh battery up front. To balance out the CG I also mounted the Galaxy Nexus up front with the camera poking out into the bubble pointing downwards. This was mostly to run My Tracks and get some performance data, but I also wanted to see what kind of video I could grab with this mounting position.
Flight impressions were great. It actually flies almost identically to the Bixler. I was expecting a dampened roll response due to the large wings but this has proved not to be the case. The flaps are some of the most effective ones I have seen in a model of this type.
- Speed at around half throttle sits around 35MPH after adjusting for wind. The moving speed was adversely affected by the wind since I spent more time flying upwind, so average moving speed cannot be used.
- At half throttle I ran through 1600mAh and traveled 7.8mi in 14 minutes. This translates to better than 5 miles per Ah of battery charge, meaning only a 6000mAh battery will be required to fly the mission goal.
- Power-off glide looks to be around 400fpm @ 30MPH. Pretty awesome.
- Climb rate is not as good as the Bixler. I do not have any numbers for now, nor would they be relevant due to the light weight. This is somewhat a concern for me as I intend to load the plane up quite a lot.
Overall things are still looking promising. The next set of tests will be performed at the estimated gross weight. I am figuring a 8000mAh 3S battery for now along with the electronics. Once I have loaded the plane up, I will re-test climb, sink, cruise and longetivity. I am also planning on figuring out what the maximum weight is for the stock power system. Stay tuned.