Staying Away from Beanfields
C. G. Prince, Flight on 7/6/07 (distances corrected on 7/9/07)
Well, perhaps it was the height of the crops that kept me in the air, or a better day, or a better plan, or just better luck, but this flight I managed to get back to the airfield! In 5 hours 54 minutes (from launch to touch down) I flew from Osceola, WI (OEO) to Chetek, to Princeton, and back to OEO. This was a total of 214.44 miles (OLC Classic; 345.11 km), and is my personal best distance for a closed-course flight. I had been setting out to do a 280 mile triangle, but when I got to Princeton it was 4:30pm, there was a big blue hole on my planned course line. Plus, I would have needed 2 or 3 more hours to complete my planned task, and I wanted to make it back to OEO without a landout. During derigging, the day was clearly fading. It seemed clear that I would not have had those 2 or 3 more hours.
One of my goals for this flight was to set a lower altitude limit and only try to thermal when I got to this altitude. For the most part, I stuck to this rule. While I was above 4,000 MSL, I would cruise to my next turnpoint, and when I reached 4,000, I would start to try to find a thermal, and then climb until I reached cloudbase or the top of the thermal, and then push on. A few times, I broke this rule (e.g., later in the day when it seemd conditions were getting weaker). In the first part of my leg leaving Chetek, I hit my best thermal of the day when cruising, and even though I was at about 4,800 MSL, the strength of the thermal was too good to turn down. During most of the climb, it showed approximately 500 feet per minute on my averager-- from my flight logger, in 5 minutes I climbed 1,820 feet. Not bad! Here's an image of the climb (via the .kml file generated by OLC when the flight trace was uploaded). The bottom of the climb was approx 4857 MSL, the top 6678 MSL, and so with the 10 turns I did, that makes about 180 feet gained per circle.
The day started off well. The sky was blue (even in Duluth when I started driving down), the morning was cool, soaring forecasts looked very good, with strong thermals predicted and light winds (I'm not sure if the cows were standing). My original plan had been to fly a 200 mile triangle: OEO, Rush City, Fedor, and back to OEO. But with the strength of the soaring forecasts and the light winds, I extended that plan to OEO, Chetek, Fedor, and back to OEO for a 280 mile triangle. Even though I didn't complete my task, I think it was worthwhile changing my plan. I made it farther than 200 miles, and I think it was good to have my initial leg downwind. I think it's easier to stay up in weaker conditions when flying downwind-- one comes across more thermals because one covers more sky and ground.
The day also ended well. I made it back to the field at 3,400 MSL, and bled off altitude doing some practice slips and and turning slips. I have been reading Bob Wander's Safer Soaring, and I want to be ready for the day that something goes afoul with my flaps (or spoilers in another glider). I learned that my 1-35 maintains reasonable airpseed indications when slipped. Andy Power had done his five hour duration flight that day too-- and landed a few minutes before me. He and I were acting as "in-air" crew for each other. If one of us had landed off-field and the other made it back, the other would have acted as crew to retrieve. Tyler Hastings helped the both of us derig. Here is the OLC link for this flight.