I'm 99% sure Air Cadets VGS units still teach turnbacks on the Vigilant successfully.
Techniques to be used are dependant on headwind component and from memory go something like this:-
<10kts headwind
EFATO <300 land ahead
EFATO >300 <500 Turn back
EFATO >500 mini circuit.
>10kts headwind
EFATO <500 land ahead
EFATO >500 mini circuit.
The emphasis however, is always placed highly on getting the correct speed before starting the turn, 65kts in the case of the Vigi.
It can be good sport buzzing the tower on a legitimate turnback exercise !!
The Vigi is an SLMG though and is really an exception to the rule, wouldn't fancy trying it in a C172 or similar from 500'
Interesting reading though, its something I've given a lot of thought to recently, particularly during a night departure with hostile terrain ahead.
Regards
UA
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Something will always spoil your fun.....
Beer has the Hangover, Sex has the STD, GA has the CAA !