Has the "start arc" been seriously considered? This is a start line
that arcs towards the turnpoints at each such that the distance to the
center of the first turn is the same no matter where you start. It
would still be advantageous to start at the upwind part of the arc,
but you wouldn't be able to get an extra ~5mi on top of that by going
through the side of a cylinder. This is somewhat more complex to set
up, but most modern flight computers have been programmed to support
it and I know its been used in Europe, although have no idea how
successful it was.

2C

While I do not have any competition experience with gliders, something
I hope to change in 2008, I have competed for many years in hang
gliding competitions. For start cylinders we use two types; the
traditional exit cylinder and an ENTRY cylinder. The entry cylinder
is a large diameter cylinder, typically centered at the first turn
point or beyond it. Lets say the first turn point is 50 miles away,
the entry cylinder could be defined as a 45 mile diameter. Your start
time is determined when you last ENTER the start cylinder. The theory
for this approach is the diameter of the cylinder allows for more
spreading out of the competitors and allows the pilot to determine
best positioning for running to the first turn point. One thing that
you have to ensure is that the diameter of the entry cylinder is large
enough to prevent pilots from flying around the back side, entering
the cylinder from behind and proceeding to first turn point. This
issue can also be addressed by making the center of the start cylinder
also your first turn point.

The ENTRY cylinder sounds similar in concept to the startline arc
mentioned above. The entry cylinder has been very successful for hang
glider and paraglider compeitions.

Ron Gleason
DG303 N303MR