What was found
AIRCRAFT DEPARTED, ABOUT 5 MINUTES AFTER LEVELING OFF, RT ENGINE SPUN DOWN. LANDED BACK AT BASE WITH SINGLE ENGINE, WITHOUT TRYING TO RESTART IT. NOTICED THE RIGHT TORQUE GAUGE DROPPED, BUT DISREGARDED IT BECAUSE ALL OTHER GAUGES WERE NORMAL. MECHANIC DISPATCHED AND INSPECTED ALL LINKAGES AND CONNECTIONS OF ENGINE COMPONENTS. MAXIMUM POWER RUN DONE ON GROUND - NORMAL. DRAINED FUEL OK. FLIGHT CHECK REVEALED PROPELLER TACH AND GG INDICATOR FLUCTUATED. CHANGED. OPS CHECK OK.