TM 1-1520-238-23 B-170 Change 3 (1) (6) (5) (4) (3) (2) MAINTENANCE LEVEL GROUP NUMBER REMARKS CODE TOOLS & EQUIP REF CODE DEPOT (D) AVIM (F) AVUM (O) MAINTENANCE FUNCTION COMPONENT/ASSEMBLY 1328 DUCT ASSEMBLY, AIR REMOVE 0.6 27, 154, COOLING INSTALL 0.6 199, 262, REPAIR 1.6 376 1329 DUCT ASSEMBLY, AIR REMOVE 1.0 27, 154, COOLING INSTALL 1.0 199, 262, REPAIR 1.8 376 1330 DUCT ASSEMBLY, AIR REMOVE 0.6 27, 154, COOLING INSTALL 0.6 199, 262, REPAIR 1.6 376 1331 DUCT ASSEMBLY, AIR REMOVE 0.6 27, 154, COOLING INSTALL 0.6 199, 262, REPAIR 1.6 376 1332 DUCT ASSEMBLY, AIR REMOVE 1.0 27, 154, COOLING INSTALL 1.0 199, 262, REPAIR 3.2 376 1333 DUCT ASSEMBLY, AIR REMOVE 0.9 27, 154, COOLING INSTALL 0.9 199, 262, REPAIR 3.9 376 1334 DUCT ASSEMBLY, AIR REMOVE 0.6 27, 154, COOLING INSTALL 0.6 199, 262, REPAIR 2.9 376 1335 DUCT ASSEMBLY, AIR REMOVE 0.8 27, 154, COOLING INSTALL 0.8 199, 262, REPAIR 3.1 376 1336 FAN, VANEAXIAL REMOVE 0.8 27, 154, INSTALL 0.8 262, 376 OVERHAUL 1.7 133601 DUCT ASSEMBLY, AIR REMOVE 0.7 27, 154, COOLING INSTALL 0.7 262, 376 REPAIR 2.3 1337 FAN INSTALLATION REPAIR 0.1 27, 154, 262, 376