31 May 2009

A busy summer weekend

After that first nice spring weekend May did not provide us pilots with the usual record breaking conditions. It was rainy, windy, or both, or then sunny but too windy. But this last weekend was nice again, with challenging "dry" thermals in a perfect blue sky.
On dry, "blue", thermal days the ceiling of the boundary layer with thermal activity is lower then the height at which the humidity in the air would condensate so no clouds are formed. Apparently these conditions are more difficult to predict as the forecasts for this weekend have been too pessimistic by quite a large margin.

On Saturday the usual group of enthusiasts/optimists gathered at Kiikala airfield. It was surely gonna be sunny, and me and some others simply didn't believe the forecasts of "no thermals, with a ceiling at 900 m MSL". I was towed up around 12:30 and immediately found some lift. Weak lift as expected, but lift nevertheless! Slowly I got higher and once I got to about 700 m the lift got a bit better. I boated around a bit waiting for company but it seemed too difficult for the others to get up. So despite the low ceiling of about 1100 m I pointed my glider south and started to glide towards Hanko.
Hanko is a regular goal, it is a small city on the tip of a long peninsula in the very south-west of Finland, famous for its beaches and summer life. Usually it is impossible to get there as on practically all thermal days one has to fight sea-breeze. But optimistic as we are we of course did believe the prediction of little or no sea-breeze whereas we didn't believe the forecasts claim of "no thermals" ;)

And sure there were thermals! It was actually quite easy to find them; almost in perfect text-book fashion there were thermals heated by fields, triggered by rocky hills or small lakes. Often weak, but at times with strong cores. The main trouble was the elusive nature, the cores didn't stay put at all and often I lost it and I had to hunt for the core over and over. Twice I got very low but the textbook tactic saved me. With some 25 km to go I could clearly see that smoke stack of the Koverhar steel mill and most of the time it went straight up. As Koverhar is right at the coast that looked promising, no sea-breeze!
But some 5 km later I got some really good lift, too good to be true compared with the rest of the day and got up to over 1500m. I suspected this to be the sea-breeze front and indeed once I set of for the next glide there was nothing but a south-westerly head wind and otherwise smooth air. So a little later I landed in the area of Bromarv (see track). Thanks to Karo and Make for a long retrieve! On our way home we enjoyed a nice dinner on one of Ekenäs (Tammisaari) many summer restaurant terraces.

For today, Sunday, the forecast was even worse: warmer more stable air, no thermals and a southwest meteo wind picking up in the afternoon. So of course we went to Kiikala again. I was expecting a very similar day, but it turned out quite different. At the airfield the winds seemed very light so with Juho we planned a small triangle of about 45 km. We were to approx. 15 km due south-east then 15 due west and then back to the airfield, 15 km northwest.
I was the first to get up and this was much easier than on Saturday with clear defined thermals that were not as narrow. Initially the ceiling was again at about 1100 m. I waited a bit for the others at the north end of the strip but when I saw that Juho and Jukka were clearly cranking at the south end I went there and joined them in the same thermal. We rode it up all the way and then I started to glide to the south-east. This first leg was quite easy we found some thermals along the way. A couple of times a moved around a bit in front to explore the area and to check if we still had a group.
A bit before the turnpoint, one of the junctions of the new motorway, we had a good thermal and before we reached the top I decided to fly out, take the turnpoint and then came back to the thermal. Somehow Jukka lost it here, but I don't know exactly how.
Juho and I now started to work our way west. This was against some headwind and apparently we were jumping invisible cloud streets, as we now had strong sink between bands of thermals. But it went all fine up to the next turnpoint, another junctions. There were some good fields bordered by rocky areas and small lakes, but we didn't find anything to take us back up, even to we together scouted quite an area. Minutes later we were both on the ground, approx. half a kilometer apart, after some 34km and a good 2 hours of intensive flying (see track). Thanks to the triangle task we were close to the airfield though so Leevi and Pekka were soon there with a welcome retrieve.

All in all a wonderful weekend, over 5 hours in the air, with only the minimum 2 tows, and almost 100 km total distance.
We now also have a Finnish league in the XContest and this weekends flight surely help to motivate all to try hard ;)

01 May 2009

Spring is here!

A couple of pilot friends started already yesterday, but for me it was today: the opening of the Finnish summer flying season. We gathered around noon at our Kiikala airfield and quickly prepared the towing setup. Juho K. was the first to go; he had to search a bit but just before coming in to land found a nice thermal. The same thermal caused quite a strong backwind at our start so the rest of us had to wait a while.

It is very typical at our airfields that thermals are triggered somewhere near the middle of the fields, especially if it has 2 runways that cross each other. No matter where, i.e. at what end, the start is set up, you will have wind from the back. Patience, and timing, are important, the trick is to be ready to launch when winds are nil, or light from the side or front. Often when you start the tow in a clear head wind the thermal is behind you and most of the tow will be through sink which when sufficiently bad will leave you with far too little altitude to fly back into that thermal.

I was next in line and lucky to time it right as I hit a nice thermal right near the end of the runway, at the end of my tow. Conditions were very nice, with thermals that took me up to about 1600m at 4m/s. Only close to the strong inversion at that altitude was the air truly turbulent.
As the winds up high seemed light I decided to try a smallish triangle, as an exercise. The first leg went very nice but the second leg into the wind was much more difficult than I'd expected. Sink was quite strong, but the real problem was that below 900 m the wind had picked up. On what would be my last glide I slowed down to less than 20 km/h once I was a bit lower, while still in 5m/s sink. I only just made it to the field above which I'd hoped to find a thermal. I arrived with only 50m altitude, too little to search for a thermal. A bird showed me one nearby but I was too low to go there. So after exactly one hour I was on the ground (flight track). Very happy though as it was my first flight in months, and after several weeks of bad flu my first day out. Even the walk out to the main road was a joy, in sunny warm weather. On a hill close to where I landed I saw a colony of wood anemones, a sure sign of spring in Finland.
Efka had planned to fly the calmer late afternoon and picked me up along the route, thanks! After a detours she'd also found Juho who had flown a more straight downwind track and had landed some 20 km from me.