What is F5J?
F5J is a thermal soaring competition where pilots fly together in groups using electric-powered sailplanes with wingspans up to 4 meters. An onboard motor gets the glider airborne. Then the challenge is to find lift, stay aloft, and land accurately—while launching from as low a height as possible.
Launch low. Find lift.
Each launch allows one motor run of up to 30 seconds. Launch height is the highest altitude recorded from motor start through 10 seconds after motor shutoff. Higher launches cost more points.
Make the time. Hit the spot.
Qualifying rounds have a 10-minute working window; fly-offs use 15 minutes. A precise landing earns up to 50 bonus points. Landing after the working window ends loses that bonus.
How scoring works
Flight time earns one point per full second within the working window. Add the landing bonus, then subtract the launch-height deduction. The group winner receives a normalized score of 1,000; other pilots score proportionally. Contests have at least four qualifying rounds, with optional fly-offs for the top qualifiers.