The Large Flyoff Problem?

Terry Kerger attributed the very large B flyoff at the Maxmen to excess performance (SEN 2117). Actually, the average contest size at the Kiwi, Pan Am and the Maxmen was 52 fliers, of which a third were Americans or Canadians. On average, 71% made the flyoffs.

The obvious culprits were (1) the extraordinary calm weather spanning the two weekends. Foot retrieval, particularly by foreign fliers, did not put them at a disadvantage. (2) The large number of excellent fliers, resembling a world championship or large European world cups. (Large local B contests in California and adjacent states plus the Nationals can reach 20 fliers, but the rest are small (3-6 fliers) or are solo flying.)

Another contributing factor is (3) the way the thermal flights are timed. There are three standard timing modes. In the States we fly-one-time-one in the thermal rounds. (Having a dedicated timer is a big advantage). At the KiWi and Pan Am fliers had no pole assignments while at the MaxMen fliers were grouped in fours and rotated along a line with poles set about 7 meters apart. Since up to half the models could be timed simultaneously, there were typically two massive launches during each round and those who missed out were left to fend for themselves.

The second timing mode are dedicated timers on poles, common in Europe such as at the Eurofly. A pair of timers are assigned by the organizers with 5 fliers per pole flown in 5-rounds with 75 minute rounds. (Interestingly, the timers rotate along the line while fliers fly from a fixed poles.) Each group of fliers choose their flying order each round. In my pole the fliers rotated each round, and the one who flew first rotating to the last slot next round. I was told by Alex to start winding as soon as he launched. Under this setup, there were 3-4 launch waves in the first part of each round.

The third timing mode was used at the Swedish Cup contests (that included a Swedish, Finnish and Danish World Cups – an analog to Fab-Feb). Each flight had to be timed by two timers. (I pair up with Carrol Allen and his wife Suzan.) All events (A, B, C and Q) tended to cluster together and a number of times I had to nudge an A flier to shift his line to allow winding. In fact, a number of models collided with tow-lines. F1A launches generally market thermals for the others. Typically there were two launch wave each round and more diffused flying later. Reasonable flyoffs sizes at the Swedish contests are attributed to weather conditions that constantly changed during the day.

Although these last two timing modes have smaller mass launch waves, I strongly doubt if Americans will opt for pole-timing or to a fly-one-time-two approach at large contests. Instead, we should abandon the unstructured cluster flying at large contests and use flight lines with pole positions, including a rotation over the thermal rounds – like at the Maxmen.

But that’s not all. To challenge fliers, we should set the flight line at a shallow angle to the drift/wind, say at 30 degrees. (Note that positioning the line straight down the drift/wind impedes timing low flying models because of people and equipment down wind. However, this would work in small contests.) Setting the line at an angle would advantage those at the back of the line (in terms of piggy backing) while compel those up wind on the line to choose their own air. Because fliers rotate through the line in the thermal rounds, they can piggy back half the time, choose their air the rest of the time – thus helping the better thermal pickers.

Good weather generate large flyoffs. At the Eurofly, calm weather under a low cloud ceiling resulted with a large B flyoff. Because the daylight was short (early November) the organizers opted for flying in two shifts. (Followed by a head to head flyoff next morning with the same number of fliers from each shift. However, this only works when both shifts don’t maxout.) It was evident that the weather conditions deteriorated for the second almost-at-dusk shift. Critics claim that flyoffs in shifts are “unfair”. George Batiuk has suggested that something like a flier’s raking (World Cup ranking; last year’s American Cup ranking) be used to “fairly” allocate the fliers in shifts. (That is, distribute the better fliers evenly.) Personally, I consider “fairness” as an ex-ante concept. Rephrased, if one shift had all the “better” fliers, it would not invalidate the results.

But very large flyoffs, such as the B flyoff at the Maxmen, have exceedingly long flight lines. It was evident that conditions varied along the line ex-post. In other words, most those who made 6 minutes flew from a specific portion of the line. Also, very long flight lines can be uneven in terms of terrain and visibility – which was NOT the case at Lost Hills.

I queried Jama Danier about why he missed the MaxMen’s 6-minute flyoff. He said that although he could feel the conditions at 50 meters, he could only guess those at a 100 meters. In short, the element of luck in flyoffs can’t be eliminated.

Aram