On Thursday, August 20, 2015 at 4:13:42 PM UTC-7, Papa3 wrote:

Took a look at this - thanks. Observations in-line.

Since you asked. Last day of Dannsville 2014 (avaialbe on the SSA Website). If you pick my file, UH, SM, XC, MS, and W3 at minimum, you can see that I made two critical decisions thanks to FLARM. First, I was able to see where a few guys were out of the gate and headed in that direction. Note: It was a very unusual task (don't go there - we know your feelings on MATs). There was a choice of 3 or 4 waypoints as the first turn. It was also very hazy with a crazy mixed cloudbase with some climbs going up much higher than the surrounding cloudbase. When I started, I was out of visual range of the others who had chosen Loon Lake as the first turn.

(It looks like everybody was in a thermal together, some headed out and you went back and too a couple of turns in another thermal and left three minutes later. When the others (UH, XC, SM) set course for the first turn you were 0.22 miles away, so you probably had a decent idea where they were headed - or could have known - without Flarm. On a hazy day whether you'd have been able to spot them visually (or get within the requisite 1.25 stealth miles) is not clear).

So, that made Decision #1 easy (where to go first). I then picked up MS climbing via FLARM and made a beeline for him. Good climb, but wasn't happy where he was going after that.

(Well, it was a good climb for MS, who was the first one in the thermal - 3..3 knots. The second glider in the thermal was SM, less than a mile in trail who got 3.8 knots. After that was 44, 1.7 miles behind MS, who only got 2..6 knots. You were 4.25 miles back and got there 4 minutes later. For your Flarm leeching prize you were awarded...1.4 knots and 269 feet of climb (this is all per SeeYou). You also made a 90-degree left turn to get to the next thermal that MS found 3.5 miles away. He got a 2.8 knot climb. 44 was Stealth mode leech distance behind and was awarded 2.4 knots. You were a full 3.75 miles behind and by the time you got to this thermal you were alerted to by the magic of Flarm you were able to achieve...1.4 knots. Had you gone straight and run into the same thermal as UH, XC and SM who knows what you'd have gotten - they achieved 1.4-1.6 knots, so a little bit better that you got with your Flarm-inspired deviation. It's not clear if the deviation was off course, or you just turned early - I didn't load the waypoints, or your flight claim).

Good news - several gliders off to the right per FLARM. I'll go there since I already have tactical advantage (i.e. I won the Start Gate). Decision #2 helped by FLARM.

(You had about 7 miles separation when you set out from the prior thermal. From that point on, you and the other three were on a converging course (does your Flarm get 7 miles or was that just happenstance? It was more or less the course you were on already). It looks like you deviated more steeply to meet up with them from about two miles apart, which probably cost you a fraction of a mile. It's not clear that Flarm did you any good on this as you would have met up anyway - at least with Stealth mode - if it was pea-soup hazy maybe you wouldn't have ever gotten an actual eyeball on anyone.)


From there, SM, XC, and I made up a very nice working group that did EXACTLY what good working groups do - one guy would lead out and the other would spread out. SM and I were in 18M span with XC in 15, so all XC had to do was to stay with us and not get dumped. He's way too good a pilot to get dumped, and he ended up winning the day (as he should).

(Loose team flying out on course has been common practice for generations, not really related to Flarm. We could invoke penalties for "team flying" anytime any gliders take two or more thermal in a row together - per their IGC files. It would be pretty easy. However, despite the "cheaty" nature of it, I think people kind of enjoy it. The "stay with the group and win on handicap" is harder than it seems, but even so there have been occasional calls to"legislate" it away).

So, there's a real-world example of where FLARM helped make some critical early decisions that got me connected with the pack and then helped me get connected with a good working group. The 4-5 minutes I gained put me in second for the day, just out of first.

(I'd have to load all the waypoints and the task, but it appears that the Flarm-related activities actually hurt you slightly (slower climbs that the non-leechers, by a good margin. It seems from the flight data that you actually earned your second by flying better on the non-leechy parts of your flight.

BTW, as I go through the "leechy" contest days people have sent me to look at, this is becoming a common theme. The first glider in a thermal pretty consistently gets the best climb. OTOH, followers - particularly as they get more than a mile or two behind - pretty consistently get substantially poorer climbs. I won't claim it as a universal truth but if you think for a minute how pilots decide whether to stop for a thermal they found versus one someone else is already climbing in you can start to see how the performance statistics would get skewed. Chasing someone else's thermal from more than a mile or two out is often a sucker's bet, and the worst part is you don't even know you were snookered until the flight is over and you can look at all the logs.

Veeery interestink.

9B