I learnt about flying from a visit to the local grass field with my brother-in-law to fly his new 0.15 FUJI engined power model. He didn't have a receiver, So I went off and bought one straightaway. It was a lovely sunny day with no wind or clouds and we got the motor started Ok. But found that the throttle could not be shut down to low tickover, only high tickover. On a full tank I launched it and Tony flew it well but we noticed it clinbing like a lovesick angel even on low throttle stck. Eventually after it had got quite high I took over and said "its OK on a sunny day with no wind to let it climb". Well I flew it in tight circles for a long while to stop the climb at 1000ft but the FUJI motor used very little gas so it still had another 15mins of power left at low throttle. Well I let it climb again and it did still under perfect control. Eventually it got difficult to see under the blue sky, and it just kept going up at a slowish speed. We had not realised it was in a strong thermal off the farmers sod field. So It went out of site straight up but still could be heard as I put it into a spin. It went wowee, wowee, wowee as It spun but it stll went straight up and up until we couldn't hear it anymore. A car ride didn't find it so we gave up. Robin Andrew