TM 5-6115-434-12 Table 3-2.  Preventive Maintenance Checks and Services-Continued Interval B - Before operation A - After operation M - Monthly Item Operator Org. D - During operation W - Weekly Q - Quarterly Number Daily B D A W M Q Item to be inspected Procedure Reference 16 x x Electrical wiring Visually inspect for evidence of burned, frayed, or Para 2-1a(5) otherwise damaged insulation.  Check terminals and connectors for secure connection. 17 x x Fuel filter elements Replace fuel filter elements each 250 hours of op- Para 3-17, 3-18, 3-19 eration. 18 x Air pressure regulator filter Inspect and clean filter element each 2500 hours of Para 3-72 element operation. 19 x x Fuel atomizer Inspect and clean fuel atomizer each 250 hours of    Para 3-25 operation. 20 x x Igniter plug Inspect and clean igniter plug each 250 hours of Para 3-48 operation. 21 x x Combustion chamber liner  Inspect and clean liner assembly each 250 hours of   Para 3-25 assembly operation. 22 x x Doors, panels, frame, Visually inspect for damage, corrosion, or other structural parts, and evidence of deterioration. insulation material 23 x x Hinges, fasteners, Inspect for damage and corrosion. receptacles, con- nectors, and fittings 24 x Check for cleanliness, leakage, secure installation, corrosion, and other damage. 3-5