INSTRUCTOR WITH SPI MAKES OFF ARPT LNDG WHEN PRACTICING EMER LNDGS.

Narrative

AFTER PRACTICING BASIC VFR MANEUVERS AND A SIMULATED EMER ENG OUT APCH AND GAR AT LQK RETURNING BACK TO GMU (HOME BASE) AT 2500 FT MSL; I SHUT OFF THE FUEL SHUTOFF VALVE MOMENTARILY (10-15 SECONDS) TO SIMULATE AN ENG FAILURE. THERE WERE SEVERAL EMER LNDG FIELDS AVAILABLE AND THE 10 HR STUDENT SLOWED THE AIRPLANE DOWN TO 50-55 KIAS. THE STUDENT WENT SLOWLY THROUGH THE EMER CHKLIST BUT BECAUSE OF THE LOW AIRSPD THE ENG RPM DETERIORATED SO RAPIDLY THE ENG STOPPED TURNING OVER ALTHOUGH I TURNED THE FUEL ON; MIXTURE RICH; THROTTLE AT IDLE; CARBURETOR HEAT ON AND PRIMER IN AND LOCKED. I ASKED THE STUDENT TO START THE ENG WITH THE STARTER KEY BUT THEN DECIDED TO DO THIS MYSELF. THE STARTER ENGAGED BUT DID NOT TURN THE ENG OVER. THEREFORE I DECIDED AFTER 3 ATTEMPTS TO AIRSTART THE ENG BY PITCHING DOWN AND FLY 100 KIAS. BECAUSE THE STARTER WAS STILL ENGAGED THE ENG DID NOT TURN OVER. I INFORMED GREER APCH WE HAD AN ACTUAL ENG FAILURE AND LANDED 10 W OF 7A1 IN AN ALREADY SELECTED FIELD. NO INJURIES AND DAMAGE OCCURRED. WE COMPLETED THE SHUTDOWN CHKLIST AND INFORMED GREER APCH AND THE FLT SCHOOL WE WERE OK. AFTER 1 HR THE A&P MECH CHKED THE AIRPLANE; NOTED THE STARTER WAS STILL ENGAGED AND MADE THE STARTER TURN THE ENG OVER. LATER WE DISCOVERED A PARTIALLY FAILING STARTER SWITCH WHEN THE PRESSURE APPLIED WHEN TURNING THE KEY IS TOO HIGH. COMMENTS AND ATTRIBUTING FACTORS: I DID NOT REACT FAST ENOUGH TO PREVENT THE ENG FROM TURNING TOO SLOW TO RESTART QUICKLY AND EVENTUALLY STOP TURNING. I LET THE AIRPLANE BEING SLOWED BY THE STUDENT TOO MUCH SO THE PROP STOPPED WINDMILLING. THE STARTER SWITCH HAD A MECHANICAL PROB UNKNOWN AT THAT TIME TO ME. I SHOULD NOT HAVE TURNED THE FUEL SELECTOR OFF AT A POS/ALT THAT DID NOT PERMIT A GLIDE TO AN ARPT. THE HIGH AMBIENT TEMP MAY HAVE CAUSED VAPOR LOCK. I WAS OVERWORKED AND TIRED AT THE TIME OF THE EVENT.