The day we arrived at RAF Ternhill to start the Piston Provost Course two aircraft collided after number one overshot from a low level practice engine failure after take off and hit another Provost from the under side which had just taken off. (4 killed).
In 1960 at Ternhill the call when you did a practise engine failure after take off was "Fanstop" so as to warn those taking off behind you. Probably to avoid the same thing happening again seeing even then there was no radio calls once in the circuit.