Nick’s post-contest performance analysis

Nick’s post-contest performance analysis

After an important contest, it is important to do a critical review of performance to determine what went right and what went wrong with the goal of improving for the next time, and passing information to other pilots considering contest flying. There are two aspects to review, the glider performance and the pilot performance. Prior to the contest, preparation was very important, and preparation of the glider included proper polishing, a review of all control surface seals, and installation of proper intrumentation, software and loggers. Because of the heat, I asked Christine to make me some light white cloth covers for the PDAs I was using, to keep direct sunlight off the units and minimize overheating problems. I normally fly in 18m configuration and for the pilot preparation, I flew all year in 15m configuration to be “at one” with the glider. I flew in 3 contests and did some record flying.

I knew going into this contest that I would be at a slight disadvantage with the LAK-17a, now an older design, limited to 500 kg all up weight. It is an 18m design with a compromise shortened wing in 15m. Newer gliders are limited to 550 kg in 15m and 600 kg in 18m, and with the strong conditions in Uvalde, a high wing loading is crucial. In 15m class, the contest rules limit the maximum weight to 525 kg, so I was only down 25 kg and with a high aspect ratio, the wing loading deficit was not very large, but was, nonetheless, a deficit.

I had an overheating problem with my main logger early on during the practice days. Although this logger was not in direct sunlight, the ambient 42 C temperature caused it to fail. Everyday, I put an icepack on it an hour before flying and removed it before take-off and had no further failures. Dan Daly had brought his Volkslogger as a spare which I installed as a third unit, just in case. I also had a problem with my mechanical vario where the needle would get stuck on the stop when the thermal strength peaked above 10 knots. I had to vigourously tap on it to free the needle on a regular basis during most flights, a real annoyance that I hadn’t prepared for because it never happened before getting to Uvalde. Other than that there were no other issues with instruments, radio or flight software.

At the beginning of the contest it became obvious that I wasn’t climbing as well as other pilots and was constantly getting out-climbed. On successive days, I changed the CofG from 75% to 85% to see if I was better able to climb. No change. I tried halfway at 80%. No change. I then tried the other way at 65% but still no real difference. By the middle of the contest, I noticed that in some cases, I could climb just better than the Dianas, at par with the ASW-27s and slightly worse than the Ventus-2s, but in most cases, I was outclimbed by all. I finally figured out that the difference was related to the smoothness of the thermal. In relatively smooth thermals, I could climb as well as others, but in broken and turbulent lift, I fell behind badly. Now that I knew what the problem was, I tried some solutions. First, I tried flying faster in turbulent lift and at higher bank angles. Then I tried with a flap setting of +1 instead of +2 because of the higher speeds, and I also tried reducing the electronic audio from 2 second damping to 3 second damping, to reduce the amount of corrections I was making for centering thermals – perhaps I was falling off the edge of the narrow thermals. All attempts had limited success, and I was frustrated by the issue. By the end of the contest, whenever I encountered a turbulent thermal, I would skip it if I had reasonable height to proceed, and take only the relatively non-turbulent ones, and this resulted in much better average speeds, and a 10th place finish on the last day. Now, is the problem glider or pilot related? The only way to find out is to swap gliders with another pilot and fly in close proximity in turbulent conditions and see what happens…

On glides between lift I also noticed that when the airspeed was 90 knots or less I would end up at the same relative height to other gliders at the next thermal, but at 100 knots plus, I would lose a few hundred feet. The 25 kg deficit was probably the cause, although on the last day I flew against a Ventus-2bx at 120 knots on final glide and lost virtually nothing. But then again, polars for gliders at 120 knots are very close. There is no question that choosing your path between thermals is crucial as I’ve lost hundreds of feet on gliders 1000′ away to the side and have gained the same at other times. Consistently choosing the best path results in significant height recovery and higher average speeds.

I prefer and normally fly by myself in contests but the flaw with that is that you may not find out about a performance problem and therefore cannot address the issue. In a contest with lots of pilots, you can get to fly with other pilots in close proximity for long periods and learn from the experience.