TM 1-1520-238-23 B-5 GROUP NUMBER DESCRIPTION 00 Aircraft System 01 Aircraft General Servicing, handling, inspection re- quirements, lubrication requirements, overhaul and retirement require- ments, cleaning, mooring, towing, jacking, hoisting, preservation re- quirements, weight and balance re- quirements, spot painting, complete painting, and subassembly painting requirements. 02 Airframe Structure Fuselage, empennage, pylons, wings mounts (engine and transmission), armor, seats, ramps, decks, and tiedowns. 03 Landing Gear Landing gear, skids, floats, skis, struts, wheel brakes, and mechanical mechanisms. 04 Power Plant Removal, installation, cooling sys- tems, air induction, exhaust, oil sys- tems, components, ignition systems, power control, harnesses, carbure- tors, fuel controls, pumps (engine driven), filters/particle separators, and Quick Change Assemblies (QCA). (See Power Plant Items, fig- ure 2, for more detailed functions.) 05 Propellers/Rotors Systems Propellers, governors, rotors (main and tail), hubs, blades, dampeners, stabilizer bars, and swashplates. GROUP NUMBER DESCRIPTION 06 Drive Train Systems Transmission, gearboxes, clutches, shafting, oil systems, bearings, hang- ers, oil tanks, and freewheeling units. 07 Hydraulic and Pneumatic Systems Pumps, filters, reservoirs, cylinders, valves, servos, motors, starters, and accumulators. 08 Instrument Systems. Flight instruments, navigation instru- ments, engine instruments, miscella- neous instrument (i.e. clocks) send- ing units, panels, and flow meters. 09 Electrical System Motors, actuators, regulators, gener- ators, starters, batteries, lighting, caution and warning lights, inverters, fault isolation systems, rotor brakes, and avionics provisions. 10 Fuel Systems Tanks, cells, filters, pumps, valves, auxiliary fuel systems, and refueling systems. 11 Flight Controls System Control sticks, pedals, cables, pul- leys, push-pull rods, torque tubes, quadrants, force gradients, control surfaces bellcranks, and trim actua- tors (mechanical). 12 Utility Systems Fire detecting/extinguishing systems, oxygen systems, windshield wiper systems, mirrors, and de-ice/anti-ice systems.