TM 1-1520-238-T-4 Change 1 6–133 6–61. HOD NGB 1 READING – DISPLAYS HIGH OIL TEMPERATURE 6–61 Tools: Nomenclature Part Number Tool Kit, Aircraft SC518099CLA01 Mechanic’s Tool Kit, Powertrain SC518099CLA013 Repairer’s Personnel Required: 67R Attack Helicopter Repairer 68D Aircraft Powertrain Repairer/NDI 152FG Maintenance Test Pilot References: TM 1-1520-238-23 TM 1-1520-238-CL Equipment Conditions: Ref Condition TM 1-1520-238-CL Engine 1 operating WARNING Turn off power before detaching or attaching wires and connectors. High current 28 VDC or 115 VAC is present. Failure to do so could result in death or serious injury. 1. Check HOD display for NGB 1 oil pressure reading. Is reading 28 LB or lower? YES Go to paragraph 6–45 to troubleshoot HOD NGB 1 display. NO Go to step 2. 2. Check pilot caution/warning panel OIL HOT NOSE GRBX 1 indicator. Is indicator lighted? YES Go to paragraph 6–63 to troubleshoot OIL HOT NOSE GRBX 1 indicator. NO Go to step 3. 3. Check pilot caution/warning panel OIL PSI NOSE GRBX 1 indicator. Is indicator lighted? YES Go to paragraph 6–47 to troubleshoot OIL PSI NOSE GRBX 1 indicator. NO Go to step 4. 4. Check HOD display for NGB 1 oil temperature reading. Is oil temperature 121 C or higher? YES Go to step 5. NO NGB 1 oil temperature is not critically high. Go to paragraph 6–13. 5. Inspect NGB 1 for cooling fin blockage (TM 1-1520-238-23). Is there blockage? YES Clear cooling fin blockage and correct damage (TM 1-1520-238-23). NO Replace NGB 1 lube pump (TM 1-1520-238-23). END OF TASK