TM 1-1520-238-23 B-168 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 1306 DUCT ASSEMBLY, AIR INSPECT 0.6 376 COOLING REMOVE 1.3 INSTALL 1.3 REPAIR 2.0 1307 HOSE, AIR DUCT REMOVE 0.5 376 INSTALL 0.5 REPAIR 2.5 1308 DUCT ASSEMBLY, AIR REMOVE 1.0 376 COOLING INSTALL 1.0 REPAIR 2.9 1309 DUCT ASSEMBLY, AIR REMOVE 1.4 376 COOLING INSTALL 1.4 REPAIR 2.1 1310 HOSE, AIR DUCT REMOVE 1.2 27, 154, INSTALL 1.2 262, 376 REPAIR 2.0 1311 DUCT ASSEMBLY, AIR REMOVE 1.1 27, 154, COOLING INSTALL 1.1 262, 376 REPAIR 2.1 1312 STUB, DUCT ASSEMBLY REMOVE 1.0 27, 154, INSTALL 1.0 262, 376 REPAIR 2.3 1313 DUCT ASSEMBLY, AIR REMOVE 2.3 376 COOLING INSTALL 2.3 REPAIR 3.4 1314 DUCT ASSEMBLY, AIR REMOVE 0.3 27, 154, COOLING INSTALL 0.3 199, 262, REPAIR 0.8 376 1315 DUCT ASSEMBLY, REMOVE 1.2 27, 154, ENVIRONMENTAL INSTALL 1.2 199, 262, REPAIR 1.8 376 1316 HOSE ASSEMBLY, REMOVE 0.6 27, 154, NONMETALLIC INSTALL 0.6 199, 262, REPAIR 1.5 376