On Dec 14, 9:03*am, John Cochrane
wrote:
Can someone please explain the intent of this:

"Rule change to add provision for restricted water to allow ballasting
of all gliders up to the
weight of the heaviest unballasted glider, in addition to current
provision that allows no ballast.
For a no-ballast day, the rule is unchanged.
“No water contest rules” will not be changed – tail water is the only
ballast allowed."

Under what circumstances, contest type, class etc, is ballasting to
the weight of the heaviest unballasted glider to be allowed?

Why does the new rule apply to weight rather than wing loading?

thanks

Andy

This addresses a situation such as Cesar Creek, where full ballast
could not be used because of a soft field. However, some pilots had a
lot of iron (motors) in the back, giving them a perceived wingloading
advantage. So now, everyone can ballast to the same weight as the
motorgliders. If it's safe to tow the motorgliders, it's safe to tow
everyone at their weight. Newcastle or Parowan might want to do the
same thing.

Why weight rather than wingloading? Simplicity. Imagine the chaos if
we have to find the highest wingloading mortorglider, then everyone
else has to figure out how much ballast puts them at the same
wingloading, then the scales guy has to verify they did the
computation right. Weight is much easier, and we felt the difference
in wing area of modern gliders is small enough that the resultant
advantage to smaller wing area gliders is not worth worrying about.
(And 3/5 of the rules committee flies Schleicher gliders... No, just
kidding)

The conventional no-ballast rules are still an option. For example, if
no water is available, or if there is no time to give everyone a fair
chance to water, weigh, and grid, then the CD can call conventional no-
ballast rules.

Fairness is also a consideration. If it's a clearly marginal 1 knot
day and there are other reasons for wanting to limit water (Mifflin, a
pain to get the fire trucks out) that argues for no-ballast rules. If
it's booming but takeoff or runway considerations are limiting water,
that argues for the water-to-same-gross rules.

Bottom line, now CDs have two options for limiting water: 1) They can
say "everyone can water up to XXX gross weight only" and 2)
conventional no-water rules. Which to use depends on the circumstance,
safety, fairness, etc. etc.

I can see we're in for some interesting pilot meetings....

John Cochrane- Hide quoted text -

- Show quoted text -

Thanks for the quick reply John. The "ballast to the same weight"
concept seems to be unfair to Std class gliders flying FAI class rules
with a combined Std and 15M contest. While most modern Std gliders
may have similar wing area, and most modern 15m gliders may have
similar wing areas, there is a very distinct difference between Std
and 15M wing areas.

Would it not be reasonable to have every pilot declare their
unballasted wing loading at contest entry. Each pilot could then
calculate, before the contest started, what ballast was required to
reach the loading of the highest wing loading entrant. It would only
take me a minute or two to fire up the laptop and open the W/B
spreadsheet to get that data.

If that's too complicated then, in the case of a combined Std and 15M
class, the Standard should be assigned a max takeoff weight that is
adjusted by the ratio of typical Std and typical 15m wing areas.

ASW-28 wing area 10.5, ASG-29-15 9.2 (area in square metres) so
adjustment factor 1.14?

Andy