SoCalSal

My Feedback: (16)

Hi, Have a 33% Waco YMF5 RCS 215 for power. Down thrust is about 1.5 degrees. Right is about 2 Degrees. 32-12 prop 46 pounds flying weight.
Here is my question. I balanced plane tanks empty, all well there. However I have a 1500 cc gas tank and a 1000cc smoke oil tank. I was out flying it today with a well experianced flyer. Gas tank was about 75% full, smoke tank was maybe 25 % full. Plane was a load to handel till we put a bit of up trim at cruise rpm. After makeing a couple passes down runway to get the feel for how the approach should set up my instructor got her down on the third pass. Now he bounced it just a bit.
While discussing the flight some of the "other" pilots noticed that my elevators were trimed with some up in them (duh) they said I needed to take out some of the down thrust so that the plane would fly level without the trim in there. And not float so bad on landing. I say the up trim was needed to counter the large fuel load and the plane would need less up trim once some of the fuel burned off. ( I only used less than a quarter of a tank on a fifteen minute flight}
Should I just leave the down thrust as is or change it? I say leave it alone as I can always reduce up trim as fuel is burned off. But what do you that know think?

Buy the way I feel that the reason it was such a floater was two things, 1 is idl trim was set a bit high and the other was the wind coming down the runway about 10-15 mph. Oh and one other thing...should I use the 32-8 prop instead of the 32-12?
Any input from you folks would really help me out.
Thanks
Steve

rmh

I would leave it alone - a bit o trim drag is a GOOD thing - As long a landings are not "floaty"with the tail wanting to settle first -you are in the best shape - as for the thrust up or down? Phooey -- more down is actually better as prop direction (angle ) is closer to direction of flight .
Where did the expert fliers get their info?
The 32x12 sounds right too -as long as the engine runs cool and in the right rpm band . Really flat props on slow turning engines are not a great combo- I run a 30x14" pitch prop on my 160 ZDZJ and THAT is still a nice landing model (a 42% 300 Extra.)
Big scalebipea area whole lot better a litle on th nose heavy side-as long as there is adequate elevator authority.
My 30% Bucker Jungman is a blast to fly -I just hate rigging it at the field.

SoCalSal

My Feedback: (16)

Thanks for your input. As far as the engine goes it is still breaking in, however I may richen it up a wee bit as I did get a momentary lag from it on take-off as I trasitioned from mid to full,. Thought I had a real problem as plane was only about 2 feet of the ground when I went to roll on the power ...no responce for a second and then that dreaded left wing drop and then full power came on and it went up.
The other "experts" were all behind the fence if you know what I mean. The pilot who was standing by me and got it trimed out flys 3D type mostley, I felt that if anyone could help me it would be him as he flys those things real good. But even at that he needed a couple of minutes to get used to a big bipe. I have been thinking about this all night and still I feel it (trim) will burn itself off as fuel and smoke burn off. This Waco will land at a walking speed if you get the hang of it, I feel that the pilot who landed it for me had too much airspeed and didn't cut the power soon enough to letit slow down and flare out.
Plane flew real good up side down ( I surley was not flying it) but Greg said it was a blast.
As you have figured out by now I'm very rustey on stick time as I got out of the sport for many years. This is the first time and plane I have flown in a very long time.

I am now started on a 33% Jungmeister from a short kit by Arizona Model Crafters . I'm shooting for a 22-24 pound target weight, What are your thoughts on a engine for this >
Again Thanks for your replie.
Steve