On Jan 8, 2:45*pm, wrote:
Guys, I think we're all stressed from lack of flying and need to calm
down a bit and stop over-analyzing this one.

Yes, the point of the "front half" business is to further discourage
starting out the back or back of the top and bumping gaggles along the
top edge of the start cylinder.

Yes, the area in which you get full credit for distance is described
by a gentle semicircle defined by the first turn fix. *Therefore, yes,
you don't know exactly where the area is before you get to the first
turnpoint.

However, nothing terrible happens to you if you start outside of the
"front half." No penalties, no invalid starts, nothing. You just don't
get full credit for distance. In typical starts out the top, a half
knot of extra thermal strength will be much more important than even
being a mile outside of the extra credit area. Remember, people used
to start out the top back when they got no credit at all for extra
distance. Knowing the exact location of the "extra credit" area is
just not that important.

Thus, if you want to start out the top, the right strategy is to look
for the best possible thermal in the front half to two thirds of the
start cylinder. Programming semicircles into your flight computer and
staring at that isn't going to do any good compared to looking for a
good thermal.

In these extreme situations such that you might be heading 30 degrees
to the left or right of "courseline" into a huge first turn area, let
me suggest that if you have no idea before start whether you're going
to head 30 degrees to the left or 30 degrees to the right, you need to
do some better pre-start thinking rather than worry about start
geometry!

Yes, this means that the very back of the start cylinder is
disadvantaged for starts out the top. The RC is very worried about the
"bump the gaggle" business, especially if the first leg is downwind.
We judged that at least to start with the benefit outweighs the cost.

In the future, we can remove or relax this rule if it is proving too
constraining. Another possibility is to remove some of the "last valid
start" language and let this simple rule alone police the "bump the
gaggles" problem. But clearly if we see bump the gaggles behavior, or
heaven forbid a crash, the whole start anywhere concept will be in
danger. Hence, we thought it better to start conservatively.

Let us know your experiences this year

John Cochrane BB

John,

If the rules committee has already made up its mind, why ask for
input?

Your comments in one of your earlier threads eluded to the prestart
issues at Uvalde under the old rules.

1. I don't see how the new rules prevents the bump and run (there is
still 5 miles from the center to the edge). I can climb up 1500 feet
over the top, and hit the edge at 90 knots and bump any thermal there
and be gone before I have spent two minutes below height to get a new
start. If I am 10 miles back at the back edge I am likely going to be
going at an angle away from the front edge and I would have to be
significantly higher so that I would not spend two minutes back in the
cylinder during the crossing.

2. It encourages everyone to start at the front edge like before. The
arc of the eventual first turn point the center of the start cylinder
limits where you should start in the start cylinder. Anyplace else
takes a distance penalty like before.

3. If the goal is to minimize the bump and run, cut the time under
altitude to a lower number or set a speed limit in the cylinder.

4. Anyone crazy enough to bump and run a prestart gaggle should be hit
with an "unsafe flying" penalty if they go through the middle of a
gaggle without working in from the outside. I think that rule already
deals with the issue.

As a engineer we work on the KISS principle of design (and rules).

Tim (TT)