What was found
PILOTS SQUAWKED THE RT ENGINE ANTI-ICE LIGHT CAME ON DURING DESCENT WHEN THE POWER WAS REDUCED TO 76 PERCENT N2. TROUBLESHOOTING THE SYSTEM REVEALED TWO PROBLEMS. NR 1: THE 300 DEGREE TEMPERATURE SWITCH WAS ACTUATING AT 340 DEGREES. NR 2: THE RAM AIR DUCT THAT PROVIDES COOLING FOR THE WING ANTI-ICE AIR WAS TORN. THE TEAR WAS LOCATED IN THE AREA OF THE COUPLING AT FS 315.0. A NEW 300 DEGREE SWITCH WAS ORDERED AND INSTALLED. ALSO, THE FORWARD RAM AIR DUCT WAS REPLACED. THIS WAS THE FIRST SQUAWK ON THE ENGINE ANTI-ICE SYSTEM SINCE SB 560-30-03, REPLACEMENT OF THE 300 DEGREE ANTI-ICE TEMPERATURE SENSORS WITH 350 DEGREE SENSORS. SWITCH PN 1173T42-3, DUCT PN X2292S4-11.