Thanks for the input. Hi Big Pistons F, another thing to check for with a comms failure is the lead from the yolk to the bottom of the dash, facilitating the PTT. Ive had 3 comms failures over the years, one was a stuck PTT that turned out to be a lose connection in the jack on the end of said lead, all it needed was a wiggle. The others were complete failure IFR in an airway in a Seneca which turned out the selector box had wriggled out of the stack a couple of mm and the third box 1 failed and i had no box 2. So 2 out of 3 were rectifiable in the air. I was just theoretically wondering what the procedure was approaching a tower controlled airfield not in a control zone.