The discussions so far are all about flap settings, take off performance and associated engine failure flight paths. After all, that was the point behind the opening question. But take off accident history should not be ignored either. A Boeing study several years ago, stated that high speed rejected take offs (whether warranted or not) have resulted in more accidents than CFIT due to a reduced climb gradient. Thus tyre failures at high speed are where danger exists rather than the statistical probability of ploughing through tree tops. Put another way, tyre failures are more likely to happen at high speed than low speed.
if you can use a lower rotate speed (less chance of tyre failure) which usually means a greater flap setting, then on balance it may be less risky than thundering down the runway at high speed with a lower flap setting simply to ensure a higher climb gradient than the performance or obstacle limited gradient.
Last edited by Centaurus; 2nd July 2013 at 12:04.