I think you'll find the polar on a 15m glider is quite
a lot flatter than that of a model. So at the entry
to the pull up the model is probably losing height
faster than the full-size ship.

The proportion of ballast you can carry in a model
is probably higher.In my Discus, weighing 320kg dry
(with me in it!) I can carry about 200kg of ballast
i.e about an extra 60%.
The models I used to fly 'when I were a lad' weighed
1-2kg, but could carry about 5kg ballast ('cos I was
less worried about pulling the wings off). This results
in a much greater benefit at high speed than you'll
get in the full-size object :-)

I also suspect the ballasted one is travelling faster
in the first place. How are you measuring the speed
of your models at the point you're starting the pull
up?

At 18:30 08 September 2003, Jim Vincent wrote:
(My money - if I had any - would be on the un-ballasted
one)


From my many years experience flying radio control
slope ships, there is a heck
of a difference in performance based on the amount
of ballast. Without ballast
I can get maybe one vertical roll; with ballast I can
get at least three or
four.
Jim Vincent
CFIG
N483SZ