engine failuire on takeoff
 

I'm late to this discussion, but: There shouldn't be any requirement for judging landing distance when an engine quits just after rotation but before gear retraction, that decision should have been made before the throttles were advanced in the first place. You should know takeoff distance and abort requirements before attempting takeoff. As Ernie says, the data is all in the book, and it's based on best case, so feel free to establish your personal minimums by adding your required fudge factor, 10% for example. I also recite required engine failure actions before taking the runway, every runway.....Most aircraft I have flown would land if the engine(s) failed while the gear was down. You might determine a runway length where, when an engine quits, and the gear is still down, you can land, and keep that figure in mind, especially as it applies to your home drome.....