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Old August 13th 13, 03:45 PM posted to rec.aviation.soaring
Dan Marotta
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Posts: 4,601
Default Junior World Championships - FAI Rules Absurdity

Hi 9B,

Agreed. A friend emailed me privately to point out the case of a 0 MC
finish. That would never have occurred to me and is another reason why I
don't compete - too chicken! ;-P


wrote in message
...
On Monday, August 12, 2013 8:41:57 AM UTC-7, Dan Marotta wrote:
Your analysis doesn't account for speed and the altitude gained by pulling
up after finishing.


Hi Dan,

Quite right, I didn't include any kinetic-to-potential energy exchange. The
number of feet involved can vary quite dramatically. In the end, because IGC
rules encourage longer tasking that use up the available day and because the
scoring for speed versus distance points yield a greater amount of gaggling
and start-gate roulette, I thought it was fair to assume that a significant
proportion of finishers would be at low McCready settings where the altitude
gained in a pullup would be on the same order as the height of obstacles to
be surmounted at the airport boundary. A 2-knot McCready starting speed
yields less than 100 feet in a pullup to best L/D speed.

There's no single precise answer to what McCready setting to use for such a
single-point analysis, but that's also beside the point. The real question
was, why is it preferable to set up the finish by rule in such a way that a
significant portion of pilots end up making low, slow, straight-in
approaches to the airport? Is it a superior way to set up the finish, and if
so, why?

9B