Interesting.

I've been doing some analysis of glider turning performance at different altitudes, wing loadings and bank angles lately - and looking at a lot of flight logs up close and personal to see how big the circles are. It turns out the typical turning radius of a thermalling glider is 350-500 feet - for a circumference of a bit over 2000' to a bit over 3000'. That's 5-7 gliders around a circle at 400' separation. That seems like too many, but it also seems too restrictive to set a vertical separation limit of 500-700 feet. You'd probably need to set a limit that's different for vertical versus horizontal distance.

I'd want to know more about how this would affect the dynamics of a gaggle. Imagine the cascading effect down a gaggle of one pilot cracking spoilers to create separation from the glider above him. There may be all kinds of other 'interenting' behaviors.

Worth a discussion.

Andy Blackburn
9B


On Monday, May 14, 2018 at 1:08:49 PM UTC-7, Steve Koerner wrote:
Here's a conceptually simple idea for contest pilots to rattle around... I believe it would be highly effective at reducing dangerous big gaggles that happen during contests. The desirables are that it doesn't damage the sport, it's effective at improving safety, it's easy to understand and it's easy to implement.

The idea is inspired by the blog comments from one of the collision pilots at the recent Hahnweide contest where dense gaggles did lead to a mid-air (fortunately in that incident all 3 pilots successfully parachuted).

Let's require flarm log files from all contestants. Let's designate a 1 point penalty whenever a glider comes within 400 feet horizontal and 150 feet vertical of any other glider. For any pair of gliders that come within penalty range, both are docked 1 point without regard to who approached who.. After 5 minutes, the same two gliders will be docked again if they come within penalty range again.

A 400 foot horizontal rule would allow two gliders to safely fly across from one another in a thermal without penalty. Perhaps three gliders could fly together in a thermal if they space out and open the circle. Most likely, though, penalty points would result if more than three gliders attempt to thermal at the same level.

The effect would be to de-motivate gaggle flying. Everyone would want to avoid crowds before the start and on task in order to keep his penalty count low. Pilots would be caused to fly their own machine and think for themselves and that would make for a better test of soaring skill afterall.