TM 10-3930-669-10 Table 2-3.  Operator Preventive Maintenance Checks and Services - CONT. Location Item Interval Item to Procedure Not Fully Mission No. Check/Service Capable If: DAILY- INTERIOR- Continued Continued 18 During Instrument Inspect panel for damage, unserviceable A malfunction/deficiency Panel instruments, and broken glass.   Monitor is observed during instrumentation regularly for proper operation which would function of all systems. damage the equipment if operation were continued. a.  Engine Oil Pressure: Oil pressure gauge is • 30 psi at idle (min.  allowable) inoperative. Oil pressure is below 30 psi. b.  Air Restriction Indicator: • Indicates more than 20 in.  Notify Unit Maintenance. c.  Ammeter: Ammeter inoperative. • Normal range is greater than zero amps. d.  Engine Temperature: Engine temperature • Not to exceed 250°F (121°C). gauge inoperable. 2-19