At the pre X-C stage in the PPL training I would always fail the radio and expect the student to recover to the airfield, this was pre arranged with ATC, the student usually had no problem with this, ATC had no problem with this, but listening to the ATC tapes it sounded like a number of other aircraft considered this some sort of crisis ( despite ATC assurances that this was just practice)
Any how the light signals worked as advertised and the proof of the drills was when one of my students had a real radio failure at night, this time it was pyro signals and all worked without drama for my student and ATC.
The biggest problem is that radio failure is not practiced enough during training and so the pilot having he failure is unfamiliar with the drills and other pilots are not sure how to react to an aircraft that is not communicating by radio.
Last edited by A and C; 21st Feb 2013 at 07:02.