PIPER PA28 ON FINAL APCH AT 1000 FT EXECUTED AN OFF FIELD EMER LNDG DUE TO SMOKE AND FUMES FROM THE INST PANEL. CAUSED BY A FAILED VOLTAGE REGULATOR.

Narrative

WHILE TURNING TO FINAL APCH; RWY 35 AT ZZZ; MYSELF AND MY SAFETY PLT WITNESSED SMOKE FROM OUR INST PANEL. AT THE SAME TIME OUR RADIO AND INST LIGHTS WERE FLASHING ERRATICALLY. BECAUSE OF THE SMOKE; SMELL AND FLASHING LIGHTS; I TURNED OFF THE BATTERY AND ALTERNATOR. AT THIS POINT; I COULD NOT RULE OUT OPEN FLAME IN THE COCKPIT; SO AN EMER LNDG WAS PERFORMED. MY COPLT READ THE EMER CHKLIST WHILE I LOOKED FOR AN APPROPRIATE PLACE TO LAND. WE LANDED IN AN OPEN FIELD WITHOUT INCIDENT. QUICKLY; WE MADE SURE THE FUEL WAS OFF AND EXITED THE PLANE. THEN WE CALLED OUR FLT SCHOOL WHO DISPATCHED A GROUP TO RELIEVE US. IN THIS GROUP INCLUDED THE SCHOOL CEO CHIEF PLT AND CHIEF MECH. IT WAS LATER HYPOTHESIZED THAT THE VOLTAGE REGULATOR WAS INOP; RESULTING IN BATTERY OVERCHARGE AND SUBSEQUENT PANEL/RADIO DAMAGE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED MAINT FOUND THE VOLTAGE REGULATOR HAD FAILED DRIVING THE ALTERNATOR TO MAX VOLTAGE OUTPUT DAMAGING THE BATTERY; RADIO AND INSTS.