On Friday, August 16, 2013 10:25:33 AM UTC-7, Ron Gleason wrote:

What Sean just pointed out is an important one to me; enforcement. The rules for the USA and IGC are defined in such way, IMO, so that software can be used for enforcement. Have scored USA and WGC contests this can easily, well kinda sorta almost, be accomplished with existing software solutions..


Important point Ron/Sean.

There are certain things that are very challenging to enforce so it's probably preferred to set up the rules so you are not dependent on enforcement that is expensive/difficult or subject to uncertainty in measurement.

It's likely easier to try to set MSH below cloud base to have than observers to enforce clearance from clouds. You could leave it to pilots to report or take pictures so as to zero out fellow competitors' scores for the day, but that seems a bit harsh/impractical too.

The two minute rule is probably more precise to enforce than a speed limit. I am not aware of anyone having been dinged for flying too fast in the start cylinder and I can imagine that it would be the subject of protest given the inherent imprecision in estimating indicated airspeed off a GPS trace.

Other summary observations from this thread:

Raising the start height (to as high as infinity) creates problems with fairness for the back of the grid unless you extend the time from last takeoff to gate open to account for tow, search and potentially multiple climbs to get to top of lift. This may be an impractically long time and could generate protests under the fair opportunity to compete provision in the rules.

Out of the top starts are generally improve task speed and generally are a preferred tactic if allowed and possible. They also have a demonstrated effect (I did the analysis personally) of spreading out starts over the entire area of the start cylinder rather than the edge. This should be beneficial to safety.

There is a challenge with pilot behavior diving into or orbiting gaggles just below MSH, combined with "clock-watching" for the two minute rule. Some of the effects of this may be ameliorated with revisions to glide computer software that automate the two minute measurement. Some of the pilot behavior may in fact be not beneficial to the pilots' performance and could be improved with education. It may also benefit from adjustments in how the rules are implemented.

There may be some benefit from line starts, but I am not really clear how or why this would be true since a line is just a segment of a cylinder with infinite radius. Food for further thought.

That's most of what I got out of it. Pretty good discussion.

9B