What was found
THE COMMERCIAL STUDENT ON BOARD WAS PERFORMING THE DUTIES OF PILOT IN COMMAND (PIC) WHILE A CERTIFIED FLIGHT INSTRUCTOR ACTED AS THE PIC INSTRUCTOR. THE OUTBOUND FLIGHT WAS UNEVENTFUL; HOWEVER, DURING THE RETURN AND WHILE ON CRUISE FLIGHT ON V21 NEAR MLD, THERE WAS A SUDDEN ONSET OF ABNORMAL VIBRATION AND A CHANGE IN ENGINE NOISE. THIS DEVELOPMENT LED TO THE DECISION TO DECLARE AN EMERGENCY AND DIVERT TO KMLD TO INVESTIGATE THE ISSUE ON THE GROUND. UPON LANDING, AN INSPECTION OF THE PROPELLER AND ENGINE REVEALED NO VISIBLE ISSUES, BUT A MAGNETO CHECK SHOWED COMPLETE FAILURE OF THE RIGHT MAGNETO. THE AIRCRAFT WAS LEFT AT KMLD, AND THE PERSONNEL RETURNED TO KSLC BY GROUND TRANSPORTATION. A MECHANIC INSPECTED THE PLANE ON THE FOLLOWING MONDAY AND CONFIRMED A FAILED MAGNETO, WHICH WAS REPLACED ON WEDNESDAY, JANUARY 29, ALLOWING THE AIRCRAFT TO RETURN TO SERVICE ON THE SAME DAY.