On Wednesday, August 14, 2013 12:22:43 AM UTC-7, wrote:
Why would you set a task that returns you on a heading other than for a direct landing? If you only have single runways why aren't you using control points to align pilots to them? Good safety concept regardless of finish height.

Well - a couple of reasons that I can think of immediately. Simultaneous direct landings onto a single runway for a large number of gliders present challenges that are significantly alleviated with a little extra altitude. Even with a 500-1000 foot finish I have seen very sporty landings when a contestant stops in the middle of the only runway. I can only imagine what happens when you don't have any option but to follow him in directly without delay. Steering turns out on course close to the finish can create high-speed converging traffic (this is often inherent if they are to be effective in steering). We had a fatal midair on the US a couple of years back under this sort of configuration. Setting the control points significantly further out means that you are restricting your tasking options. You also could require gliders to orbit say 20 miles out while they still have altitude and and get permission for a properly sequenced direct landing prior to finishing (probably would meet with significant resistance), or you could restrict contests only to airports with more than one runway (also not likely popular). Of course all these suggestions address the symptoms rather than the root cause, so why not address the root cause?

Perhaps the penalty was not awarded immediately and they were not aware at the time (they took some hours to appear), but on that day (if I have the right one) they busted the finish height and were penalized accordingly - http://soaringspot.net/jwgc2013/resu...aily/day3.html

I stand corrected. I should have checked the final scores. Odd that he thought he finished without penalty and was still nearly a mile short of making the airport. I don't think I've ever heard of that in the US.

I don't think traces were published for the accident at WWGC so let's not speculate.

Happy to wait and review later whether the pilots' intent was to finish at the top of the finish cylinder, which would be the fundamental issue in question. I can tell you from direct conversations with other participants in WGCs that they often set up final glides to finish at the top of the cylinder height that is given. They try to have extra energy, but it doesn't always work out. I think it's safe to say the fact that you see lots of glider limping back to the airport low and slow is not a random outcome - it is set up by the rules.

Back to my original question. What is the compelling reason to adopt IGC rules in the US? Which rules will represent the big improvement and why? Finish is only one out of many rules, but I've heard no affirmative arguments yet.

Are there affirmative reasons not to? If you want to be different you should have solid reasons for being so. I'm not convinced they're less safe (if you have a high finish, and someone arrives low but on glide, what are they going to do??) Learning new processes and procedures and how to fly them optimally is not something you want to be doing upon arrival at a world competition.

I think the affirmative reasons are the entire logic why the US rules are different today - in order of priority: lives, injury and property damage. I have surveyed contest pilots on this point specifically and by a significant majority they enter into their glide computer the finish height you give them - a subset add some extra margin, but dive it off at the finish if they any excess energy. They don't end up at or near the finish height you give them by happenstance. The lower you sent that number the more likely you are to have gliders limping in on low, slow "direct landings". Most airports have traffic patterns because it is viewed as safer, not less safe as you argue. I would need more education as to why low and slow is a safer way to manage post-finish approaches to landing.

This is an interesting question for another reason - 95% of US pilots will never fly in a WGC, so you are asking them to fly under rules that are potentially inappropriate for the environment in which they fly their entire lives in the name of a vague notion of consistency for the 5% that do. I think one could easily make the converse argument. The US rules are what they are and making a change will have an adverse impact on 20 times as many pilots as you argue. So again, what is the argument in favor of 50-100 meter finishes at 3-4 km other than the "why not" that you offer? What benefit does it serve?

You did offer that if the airport situation didn't allow for it, extra finish height is in order. Very few US airports have the kind of 10-gliders-across, 1 or 2-km long runways in any direction you see in other countries. So by your own admission are you saying that the US rules are more appropriate for US contest sites anyway?

There must be a reason why the IGC set it up so that gliders are limping low and slow back to the airport post-finish - can anyone tell me? It logic doesn't leap out at me and I'd really like to know why people think it's a good idea.

9B