TM 5-3820-256-10 Table 2-12.  Instrument Panels Preventive Maintenance Checks and Services ITEM INTERVAL Item to be Procedures Equipment is NO. Inspected Check for and have repaired not ready/ B  D  A  W  M or adjusted as necessary. available if: 1 X Operator's panel Check for correct readings. Gages indicate out of specified range. X  X Check for broken or cracked lens; be sure indicators function properly. 2 X Throttle Check linkage for security and correct adjustment. 3 X Air compressor panel Check for correct readings. Gages indicate out of specified range. X  X Check for broken or cracked lens; be sure indicators function properly. Table 2-13.  Control Air System Preventive Maintenance Checks and Services ITEM INTERVAL Item to be Procedures Equipment is NO. Inspected Check for and have repaired not ready/ B  D  A  W  M or adjusted as necessary. available if: 1 X Control valves Check for proper operation. Controls do not perform properly. 2 X Air line conditioner Check filter bowl for moisture accumulation.  Drain moisture.   X Check air regulator gage for correct Required air pres- pressure reading. sure is not available to operate controls. X Check lubricant level in line lubricator. Add lubricant as required. 3   X Air lines Listen for hissing that would indicate Leakage prohibits a leak in air line. adequate pressure for operating con- trols. 2-31