if anyone owns the dynaflight butteryfly what is the lowest throttle setting you can fly the plane (please give me prop size and rpm numbers)

the undetailed question
can 43.2 watts turn a 10x7 prop at >2000 rpm? (or what ever rpm/prop size can fly the plane)

the more detailed question
can i take this plane (dynaflight butterfly) http://www3.towerhobbies.com/cgi-bin...?&I=LXE616&P=0
put a rimfire 35-30-1250 on it w/
put 20 6x3 solar panels (producing 11 v at 3.6 amps = 43.2 watts)
and a 2100 lipo (if i need more power for some reason)
and fly it forever (asumbing the suns out)


2 things im worried about
weight and power output by solar panels

this would be for an after school project
as of now its a idea, but is it possible?

http://www.electrifly.com/motors/motors-ammo-20-30.html
well if i use the 20-30-5200 it turns a 8x3.8 prop at 8520 on 11.1 lipo's at 8.7 amps (95.7watts, v*amps)
a .15 la turns a 8x4 prop at ????
can anyone give me those numbers

the reviews (butterfly) state people flying for half a hour on 4 ounces of fuel (http://www.rcuniverse.com/product_gu...cfm?kit_id=256)
so with that knowledge shouldnt i be able to fly on a little less that half throttle(so im only pulling 43 amps), if my solar panels were doing the work?

basically what i need is the prop size/rpm numbers of a 15 la (or any other engine) and
how much throttle one needs to keep a butterfly in the air (rpm/prop size would be great)

to see if this is even possible

i doubt anyone will we able to help me much but thought id ask