Fair enough, I titled this thread maximun altitude because my main goal of this whole deal is to design a glider/sailplane which is best uited for flying at low and high altitudes.... And for me, determinining x,y,z that will allow me to reach the highest altitude possible is my biggest unknown. The thread is shifting gears now since I have got some good data from this thread (ie wing loading, wing geometry,AR, and building techniques).

i want to carry a payload of about 15 lbs in altitudges ranging from 100ft-15K (15K being lowest acceptable altitude- i want to go higher!). The plane will be pusher style becuase I want to avoid contaminating my data collected with unnatural air vortexes that a normal propellor system produces.

Why is pusher less efficient? i would like to hear more about this.

gopher, I may elect to surface the winglet with solar cells. Surfacing the entire wing = enormous cost. That is the main constraint to that idea!

off to class,

Brandon