RE: CMP BF109F BUILDING THREAD
Maiden flight today!!!!!!
Man I was nervous, but also strangly calm at the same time. I know, an oximorin. Anyway. The plane originally had a tendency to want to vear left on inital throttle up(like up to 1/4 throttle), but that past that, it wanted to veer to the right. The first taxi test resulted in a "controlled" ground loop. I aborted the rollout, but the wing tip never scraped.
I wasnt actually planning on flying the plane since, well, I had forgotten the wing bolts(I used larger hangar 9 hex bolts and blind nuts) and I also frackin forgot the chin piece. So, after a flying buddy found some same thread nylon bolts, I was able to get the wing on and figured I could do some taxi tests, but thats all I had really planned on.
Anyways, on the 2nd roll out test, the plane stayed a lot straighter and the tail lifted. She started to get light on the wheels and I had two choices.....punch full throttle or cut the throttle and attempt to keep it from veering off the runway as it was headed to the left side edge some.
Quick decision and I pushed full throttle.
I tried to keep the climb out somewhat flat and she did want to bank left a little. I kept a wide turn more or less flat wing attitude for this and the next few bank turns because i didnt know how she'd respond. It only took about 5 clicks of right aileron to trim it out and no elevator once I had it high enough and comfortable messing with trims.
I did not retract the gear for this flight. I was still too concerned with how she would fly seeing as she weighs over 17 pounds. Id have to say, that the plane did not exhibit any bad behavior and actually felt really solid in the air. I only have 40% set for low rates on the ailerons and it doesnt need anymore then that. It felt just right.
I did about 7 circuits of the field, most of them at full throttle as I wasnt sure how slow I could fly it yet. On the 8th pass, I dropped the flaps to half and the plane did want to climb some, but not severely. I tried a landing approach with half flaps and the plane simply wasnt slowing down enough so I kept about 25 feet up and went around. This 9th pass, I dropped full flaps on base to final leg and lowered the throttle. She still was coming in pretty fast so I went around again. This time, i was a lot lower on the throttle. There was no torque issue when pushing full throttle again for the go around. Id say i was at 1/4 throttle when I push full again.
On the next landing approach, I cut the throttle about 10 feet up off the runway and she still kept speed for a good while and simply held steady about 3 feet up for another 200-300 feet. She did then gently settle on the mains and was very controllable. There was no bounce, nothing....just a nice roll out. The only thing that happened now was that the rubber wheel came of the plastic rim of the Williams Brothers 3 3/4" vintage tires on the left side of the plane. It did not cause any problems with controlling the plane and it simply slowed down fine skidding on the rim a little.
I could have easily slowed the plane down even more, but for its first landing, I didnt want toget too slow.
So....starting voltage was 20.60 per 5s 4900mah battery or 41.20 for the total series for 10s. After the flight, the batteries read 18.75 each. The flight was about 5 mins or so. I did not have the timer with me and remember that most of the flight was full bore on the throttle.
I am very pleased with the performance. She seemed pretty fast, but not super rocket like. I am sure if I changed the prop from the current 18x12 to a 16x14, Id get a massive increase in speed, but I dont think its needed.
The plane is nose heavy somewhat, but even with the stock retract locations and the Sierra Giant gear made specifically for this CMP ME-109 used, there was no tendency for the plane to even want to nose over any.
So to re-cap:
Turnigy SK 6364-230kv with 18x12 APC e using a turnigy 100 amp 2-12s esc
2x 5s 4900 in series for 10s 4900
Retracts: Sierra Giant CMP with 3 3/4" williams bros. wheels/tires
CG was at 108mm with chin scoop. Without, probably 110mm