TM   10-4320-318-14 Item No. 11 12 13 14 15 16 17 18 Table 2-2. Operator Preventive Maintenance Checks and Services Internal During During During After After After Weekly Monthly Location Item To Check/ Service Fuel Tank Engine Engine  Oil  Level Fuel Tank Air  Filter Fuel  Hoses Air Filter Engine  Cooling Ribs Procedure CAUTION DO NOT LET ENGINE RUN OUT OF FUEL. FUEL SYS- TEM WILL BECOME AIR BOUND. During operation, check fuel level and add fuel as necessary. Inspect engine for oil and fuel leaks. Check oil level after every eight hours of operation. Refer to LO  10-4320-318-12. After operation, fill fuel tank to top. If air flow indicator is past “red” indicator mark replace air filter element (para. 3-5). Reset air flow indicator after changing air filter  element. Check for leaking fuel hoses and corroded  fuel  hose  connections. lighten  connections.  Notify  Unit Maintenance if fuel hose leaks or connections are severely cor- roded. f air flow indicator is past “red” indicator mark, replace air filter element (para. 3-5). Reset air low indicator after changing air filter element. Check for dirt accumulation and air passages. Clean as neces- sary. If rib is damaged, notify Unit  Maintenance Not Fully Mission Capable  If: Class  III  leakage. Oil level below “min” mark on engine oil dip- stick. Oil level below “min” mark on engine oil dip- stick. Dirty air filter element. Any Leak. Dirty air filter element. Ribs are dirty or dam- aged.  Air  passages  are clogged. 2-6