On Nov 1, 11:28 am, Sam Giltner
wrote:
I am concerned with the questions on the poll addressing
the sports class. 7.0-7.3. All of the questions deal
with handicaps. We have three very clear methods of
measuring performance gains for gliders. Weight, wingspan
and winglets. Changes of any one of these three factors
has been proven to change the performance of a glider.
The questions on the poll now ask if we should add
'other modifications' such as turbulators, wing root
fillets etc. to this list. I ask the question how can
these 'other modifications' be measured? Who is qualified
to do the measuring? Should we leave it to the CD to
determine what 'other modifications' qualify and to
asses a different handicap? This opens the door for
handicaps to be different at each contest depending
on the CD. Unless there is a clear method of measuring
'other modifications' leave it alone. Arbitrary decisions
have no place in determining handicaps.
7.3 even goes so far as to ask if a glider with smoothed
and sealed wings should have a different handicap from
one that doesn't have smooth and sealed wings. Is that
the same as asking if a 10 year old ASW-27 should have
a different handicap than a new ASW-27 with smoother
wings?

This is a classic slippery slope question, how far is too far?
What about someone that take a libelle 301 and reprofiles the wings to
give them them an ASW-27 airfoil?
At what point does a certain model glider get modified so far it no
longer is fair to call it by its original name [and handicap?]
Or what about replacing the entire wing with a new design?
I bet I could fit a 304 wing with its more modern airfoil onto my 303
mosquito. Would a Discus 2x wing fit a Discus etc?

This is a tough question, if you add winglets for better performance
you should be willing to accept a harder handicap. I sealed my
control rods, have no way to measure what seems like better
performance, should my handicap change?

I suppose we need to figure out what are the limits of what we
accept. Right now the rules seem to be wide open.

Adding modern aerodynamic designs/devices to older designs might be a
way to differientate the changes. If you have a glider from a certain
era and you apply technology/changes that were not common when that
design was current/new then maybe we could agree it needs to be
handicapped. [turbulators, blowholes, winglets, Dr Sinha's
deturbulator strips].

Dr Sinha's deturbulator strips do present a challenge: if claims of
20% better performance proved to be true for this technology or any
future aerodymanic innovation, would you be fine to compete against me
without changing my handicap?

I agree that it would be a massive challenge to determine what is the
"standard geometry" of a design - especially for a CD at a
gliderport. Heck what about the PIK-20 - I understand that the
production got less precise and the later ones had thicker airfoils,
which one is correct, should they have different handicapps?
What would we do, have templates for every airfoil and intersection?
[For the PW-5 they have a system right?]

Could be an interesting discussion.

Chris