The 28th of June at Challes les Eaux french northern Alps we had the opportunity to test aerotowing by a Phoenix UL motorglider.
It was very positive: stable, easy to follow at 85km/h, at full power the rate of climb was 4m/s 🙂
Unlike the Dynamic WT9, engine cooling seems to be efficient at that speed.
So far the best 3 axes controlled UL for UL gliders aerotowing.
Here is the report (in french)