Epic Late Day Solstice Flight With No Thermals

I had an amazing 33 minute late evening 2017 Summer Solstice flight with my F5J Euphoria V2. Launched at a very late 8:21 p.m EST to about 170 meters over my local field in central Pennsylvania not expecting a very long flight. Cracked my one and only Guinness Stout tall-boy at 8:22 exactly, trimmed the Euphoria for minimum sink, and sat back in my folding camp chair to enjoy the celestial start to summer.

At the top of the launch there were some initial clues that something magical was going on with the air. While absolutely dead calm and cooling on the surface, there was a glass smooth West wind up at my launch altitude and I first just pointed my nose right into it. I down trimmed just enough to penetrate the flow, and the Euphoria began to climb slowly in camber setting one. Once upwind a few hundred more meters, I felt still better energy, and I just weaved a bit cross wind left and right, finding more smooth lift and subtle riffles of lift which eventually took me up to about 300 meters. I dared not turn, but I didn’t need to, I wasn’t covering a whole lot of ground upwind and I could easily see the plane’s attitude against the glowing sunset.

At 8:45, the sun was well behind the mountains now and the ground air was cooling off rapidly, but I could still see the big black silhouette of the Euphoria well enough to try to extend this ridiculous flight as long as possible. At about 30 minutes into the flight, I could feel the conditions suddenly change, the upper level breeze got shifty and slackened, and the glider didn't want to turn any more and felt dead on pitch. Last call, the lift bar was closing. I finished the last warmish swigs of my stout and milked another few minutes of flight time over my now really dark field and then set up for my traditional hand catch. Total flight time was about 33 minutes with no thermal turns or even thermals for that matter. I know what was creating the lift, do you?

This flight was not and example of a classic 'glass off' late day heat release scenario, though this may have played a small part in creating the weird lift conditions. Since the lower altitudes had very little air movement, the ground layer cooled a bit more rapidly then the layers at 200m and above. The day’s gradient breeze was still warm and active aloft, and less dense than the building inversion below it. The warmer moving air was bouncing over the thicker lower layer, causing upward air deflections and eddies which I was able to use to gain altitude. As the sun set and the lower layers cooled further, the air at the altitude I was at quickly stabilized, suppressing the wind and thus any mechanically generated upward currents. You could feel the lack of positive lift in how the plane behaved, it suddenly felt like you were flying in sink between thermal cycles. I’ve often experienced unusual lift conditions around dusk and you should experiment with flying later in the day after the expected thermal activity has disappeared. You’ll learn a lot about the importance of flying smoothly and just maybe experience the magic of unexpected evening ‘magic’ lift.