What was found
DURING FLIGHT 3160, AT 16,000 FT, ENGAGED THE RT ENGINE ANTI ICE SWITCH. THE RT AIR VALVE ILLUMINATED QRH REF. RECYCLED TO NO AVAIL, ALSO MANEUVERED RT POWER THEN CYCLED SWITCH NO CHANGE. AIR RETURN TO MSP. MAINTENANCE REMOVED AND REPLACED RT ANTI ICE VALVE PER SAAB MM 72-00-00. P/N ON/OFF 6068T56P01, S/N ON GRTB9690, S/N OFF GRTB3641.