hi friends i have built a catapult glider with the following materials:
1.fuselage:bamboo of 0.2cmthick
2.wings:biofoam
3.tailplane:visitingcard of very tiny thickness of 0.01cm
4.fin:visitingcard of 0.01cm.
i testglided it near by ground at around hot 39celsius at 1.00pm with steady wind not wild.
problem:
1.it is climbing well but in inverted flying and reaches maximum height and lands with a nosedive straightly.
i dont know what could be the reason?please help this beginner
karthik

Tail heavy if its climbing steep and then straight down.

After balancing the model you should launch it in dead wind straight and level not fling it like a a javelin. The model must glide straight (as much as possible) and descend steadily. Once this is achieved then you are ready to catapult it.