What was found
FLT 4889 - BOS-ROC - DURING FLIGHT, IN HEAVY CLOUDS AND ICING CONDITION, THE RIGHT AIR VALVE LIGHT CAME ON WHEN DESCENDING TO A LOWER ALTITUDE. THE RIGHT ENGINE EXPERIENCED TWO POWER INTERRUPTIONS JUST AFTER LEAVING ICING. THE CREW ATTEMPTED TO ADD POWER AND THE RIGHT ENGINE SHUT ITSELF DOWN. THE IGNITION LIGHT CAME ON AND NO OVERTEMP DURING SHUTDOWN. THE AIRCRAFT WAS REPOSITIONED TO PSM. MAINTENANCE REPLACED AISBV, GARRETT VALVES AND IGNITOR PLUGS. AIRCRAFT OPERATED SATISFACTORY. (M)