At
post #657 HN39 made the following "tongue in cheek" comment -
As a student I piloted gliders. These routinely fly tight circles to stay in thermals. In a strong wind there is no airspeed loss turning downwind, nor gain turning upwind. I've never quite figured that out, may be as a physicist you can.
I don't think that everyone picked up on what he said, but the discussion over KE principles has been interesting and informative.
henra;
I believe the forecast temperature was -46°C at FL350, and I wouldn't be surprised if it was even warmer where AF447 was, e.g. -42/-43°C.