It is different Tom.

Yes, there are always climbing and cruising sailplanes
in the mix. The difference is that the closer you are
to the finish the more likely it is that gliders will
be converging on each other (horizontally AND vertically)
and the more likely it is that the cruising sailplanes
will be doing something approaching redline rather
than 75-100 knots.

The logic for the difference is simple. If you know
you can't make it home you are likely to be making
outlanding preparations somewhere around 700-1,200
feet - depending on terrain and availability of landable
fields. In the 'final glide gone bad' scenario you
would come to this decision 5-10 miles out and either
find a thermal or land (at least most pilots I know
will - unless they're flying over a terrain so benign
that it's like one big putting green). At this distance
the higher speed traffic is well higher and hasn't
started to burn off the extra altitude they are carrying
as a buffer. The climbing glider won't likely climb
up to them anyway unless it finds a real corker of
a thermal (somewhat unlikely under 'low save' circumstances).
The reason you don't often find gliders making low
saves at less than 5 miles out today is that they've
all landed out by then or made it home - put another
way not many pilots set up for a landout from 500'.

Under the proposed rule you can find yourself at 2.5
miles from home and 700' AGL with not enough altitude
for a speed finish, but enough altitude to get home.
What would you do in this situation? EXACTLY - you
will hunt around the edge of the donut for lift. aHopefully,
as you get lower you drift towards the airport to keep
the landing option open (not sure if the rule allows
for catching a thermal below 500' right over the airport,
climbing up to enough height to go out to 2 miles and
back above 500'). I suppose we could make a rule that
if you EVER get below 500' AGL in a flight you're done,
but it would probably only be enforceable in the flatlands
of Kansas.

So there you are climbing up at 2.5 miles out, trying
to get enough altitude to make it to the inside edge
of the donut at 500'. Say you'll accept a Mc=2 glide.
Well at 2 miles the difference between a Mc=2 glide
and a Mc=6 glide is 150'. So all the guys coming steaming
home - now at close to redline will be more or less
at your altitude. Under the current rules this is unlikely
to happen at less than 6 miles out - where the differential
altitude margin is three times as great and the speed
differentials are somewhat lower.

If you want some really interesting and action-packed
finishes with a few poor pilots stuck outside the donut
- able to glide to the airport but unable to finish
for speed points - floating around at low altitude
and mixing it up with gliders at redline - all within
view of spectators - then this is your best shot.

Wait, I forgot the best part! The guys at redline will
have their heads in the cockpit, looking at their glide
computers, because 500' up on a two mile radius has
no visual reference to fly against.

Democracy is a great thing, but without goodwill towards
others it offers the potential for 51% to inflict pain
on 49%. If you want to finish at 500' go ahead - you
don't need a rule for it and it costs you only a minute
or so. I personally carry 1,000' of extra until I'm
5-7 miles out.

While I believe it is 100% well intentioned, I don't
think this proposal actually helps and it has some
very funky potential side effects.

Vote away!

9B

At 20:30 20 September 2003, Tom Seim wrote:
Andy Blackburn wrote in message news:...
I shold have been clearer on this point Eric.

If you are at 700' and 4 miles, you will not make
it
to 500' at 1 mile, you will have to stop and climb.
A Mc=0 glide to the inner edge of the donut in my
ship
requires 886' (by the factory polar). If I climb to
a Mc=3 or Mc=4 glide, I am at 997' to 1053'. You might
climb even higher if you want any buffer.

I believe that the optimal finish for pilots who have
adequate altitude for a speed finish will be to shoot
for the top outside edge of the donut (with some buffer)
and then bleed airspeed to the inner edge to hold
altitude.
A pilot shooting for this on a 120 knot glide Mc=6
will be at 908' at 4 miles, which is below the guy
making a save and wanting to make a flatter glide
to
the inner part of the donut.

The simple point here is that all of this climbing
and mixed traffic happens at 4-5 miles from the field
rather than 8-10 miles under the current rules. This
is because the ground forces the issue later with
the
extra 500' built into the finish altitude. Since altitude
separation (difference in glide angle times distance)
goes up linearly with distance and the amount of horizontal
separation goes up with distance as well, the potential
for mixed climbing and highspeed traffic would likely
increase under the 500' rule. You can make different
assumptions about what altitude you might stop and
climb, but the difference due to the rules remains
the same.

I don't see how this is any different; we have to see
and avoid other
sailplanes from the time we start the flight to the
time that we have
come to a full stop. There can be gliders thermally
anywhere on
course, including directly over turn points. And even
if you don't
have the 500 ft rule there can mixing of gliders thermally
and
high-speed gliders in-bound to finish.

I feel that those low altitude finishes add nothing
to the sport
except for some broken gliders (and pilots!) and some
very anxious
crews. Furthermore, it encourages violation of FARs
for minimum
altitude. There may be some pilots who think they may
have some
competitive edge because they are willing to push it
lower than the
others, and this may be the case. I say cast your vote,
let democracy
function and accept the result.