A lot of good points made! Thanks for explanations C100driver, werbil and bookworm.
If you are an instructor and recommending turn backs I hope you have excellent professional indemnity insurance - because if someone stuffs it up and the pilot survives and says 'my instructor told me to' the lawyers for the passengers or their estates will be rubbing their hands with glee.
Most of you are all acknowledging that turn backs after engine failures is a complex maneuver with many variables and factors involved. However you constantly fail to realize that even though someone teaches or attempts turn backs, they are also well aware of these factors and might have thought them through way more than you think.
This must be the 100th time I explain this in this thread: just because I recommend or teach turn backs does not mean that I tell my student "any time you have an engine failure after take off turn back", this would just be stupid to assume in my opinion.
Of course the student must be aware of the hazards involved in doing the maneuver, but by all means, when I know for sure 100% that in most conditions (which are explained and discussed with the student) in the C-172 that there is a certain altitude at which you will make it back to the runway, hell, of course I want to let him know about it and see for himself what happens when you try to turn back to the runway on departure. Both at too low of an altitude (so he can see how dangerous it is), and also at an altitude high enough to make it.
As you all know, many accidents have happened because pilots have tried to make it back to the runway after an engine failure shortly after take off. I bet you they would not have been tempted to do so if they had the knowledge discussions like these bring forth in addition to some actual practice with a CFI (or solo). They would have seen instantly that turning back in that aircraft with that load in those conditions just isn't possible. But why do these things happen? My take on it? Bad decision making due to lack of knowledge and lack of experience. I wish for all pilots do have enough knowledge and experience to make good decisions.
And for the billionth time in this thread: if I know I can make it back to the runway if my engine fails at 600 feet (or whatever altitude would be appropriate for that day, some days there might not be a chance to turn back at all), then why on earth shouldn't I do it? Any day and twice on Sundays guys, no matter what argument you come up with this is something I have done a lot and I know it's possible, and therefore nothing can change my mind when it comes to it. But would I do it in any airplane at any airport and in any atmospheric condition? Of course not, and I have never claimed to either teach so or do so.