we are talking about that prop aircraft from canada, right??? i´m confused, because i also fly the thing and have never heard of this... but, on the other hand, i can´t remember having had to use flaps 15 for take-off. but i´m going to throw this question into the general direction of the tech. pilot and see what he has to say, seeing that i´ll be making my first journey to Naxos next month. and i think that with less than 900m of runway to play with flaps 15 is going to be an issue!!!