View Single Post
  #44  
Old December 23rd 10, 02:33 AM posted to rec.aviation.soaring
Bruce Hoult
external usenet poster
 
Posts: 961
Default USA 2010 Competition Rules Committee Minutes Posted

On Dec 19, 5:49*am, John Cochrane
wrote:
The main problem I see is that "speed to landout" can encourage you to
dive to the dirt, and needs a major calculation to figure out when
that's the right thing to do. At least my landouts seem to be preceded
by a half hour of grinding away in half knot lift at 1000 feet. (And
too many of my contest flights are interrupted by a half hour of
griding away in half knot lift!). A pilot gets a lot more points in
this system if he gives up and lands right away.


No, that's not the case.

Certainly, once no more forward progress is possible it is best to
give up sooner rather than later. But if you're heading home then it's
well worth making more progress, even if slowly.

For example, suppose you've done 300 miles at 80 mph (3.75 hours) and
are now low 100 miles from home.

If you land now you'll get 20,000 points.

If you press on and make it home for 400 miles total, how slow would
you have to be to get the same 20,000 points?

The answer is 50 mph average for the whole flight. That's 8 hours
total, 4.25 hours for the last 100 miles, average speed for the last
100 miles, 23.5 mph.

If you can stay airborne at all then you can probably manage that.


(under the alternative formula, in the same situation, you'd need to
do the remaining 100 miles at 30.2 mph, for a 56.7 mph overall
overage, to get at least the same points as landing out immediately)