I agree 100% that the effective power loss is within that range. What we have failed to look here is that we are talking about a trainer with a considerable amount of drag. If we were to calculate the efficiency of a PT-40, LT-40, ...etc, compared to the amount of thrust put out by the propeller its easy to see that the loss of power for using downthrust is practically neglible. The idea here is to provide dynamic stability to a trainer thats being accelerated while level flight. The argument was never made for any other type of model.


[link=http://www.dwtoons.com/Horse/Horse1.htm]Beating a dead horse[/link]