Date: 201206
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: DC-10 30
Operator: Air Carrier
Operating under: Part 121
Mission: Cargo / Freight / Delivery
Flight phase: Parked
Aircraft component: Powerplant Fuel Control Unit
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Lead Technician
Reporter qualification: Maintenance Airframe; Maintenance Avionics; Maintenance Powerplant
Human factors: Workload; Troubleshooting; Situational Awareness; Distraction; Communication Breakdown; Time Pressure
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Taxi
Result: General Maintenance Action
Contributing factors: Logbook Entry; Human Factors; Aircraft
Primary problem: Human Factors

Narrative: When the aircraft arrived; I went to flight deck to debrief crew while my partner performed post flight walk around. Crew reported all three engines remained at Flight Idle until shutdown. Note: At this time my partner reported panel missing at # 1 forward fuel boost pump and an Engineering Authorization (E.A.) was initiated. Upon visual inspection of flight deck I found 'Eng Grd/Flt Idle Cont' Circuit Breaker (C/B) (B1-1270) open [popped]. At this point I conferred with Maintenance Control/Engine group with my findings; and generated DC-10 Maintenance Manual (MM) 73-20-03-2 and DC-10 Systems Schematic Manual (SSM) 73-00-0; Page 101 for Troubleshooting Procedures. In Accordance With (IAW) DC-10 SSM 73-00-0; disconnected # 1 Eng Flt/Grd [Ground] Idle Solenoid Cannon plug to isolate malfunctioned solenoid. When attempting to close Eng Grd/Flt Idle Control C/B; the C/B continued to pop. I then disconnected # 3 Engine Flt/Grd Idle Solenoid Cannon plug to isolate it. I then was able to successfully close the Eng Grd/Flt Idle Cont. C/B. IAW DC-10 MM 73-20-03-2; I secured # 1 Engine Flt/Grd Idle Solenoid Cannon plug and verified audible click of solenoid when energized. C/B remained closed. When attempting to verify # 3 Engine solenoid by re-securing Cannon plug; the 'Eng Grd/Flt Idle Cont C/B popped. At this time I determined # 3 Engine Grd/ Flt Idle Solenoid to be bad. I conferred findings with Maintenance Control Engine group and agreed to MEL # 3 Engine IAW MEL 73-21-01-01. I then complied with MEL MAINTENANCE PROCEDURES. At engine start; flight crew confirmed Engine # 3 started in Flight Idle and # 1 and # 2 engines started in normal GRD Idle. Multiple events occurred and there were many details that needed attention; in addition to several interested parties wanting answers at the same time. I complied with required maintenance procedures; but failed to include description/explanation in the aircraft logbook. Taking one step at a time would assure all pertinent information is included in the logbook despite the pressing Estimated Time of Departure (ETD).

Callback: Reporter stated he was informed the next morning from one of their Maintenance Controllers that he had not explained in the logbook; or entered in their maintenance computer; how he arrived at determining the cause of the Circuit Breaker (C/B) popping to justify deferring # 3 Engine's Main Engine Control (MEC) GRD/Flt Idle solenoid. What was frustrating; after receiving that call; was the fact that the previous night after he had arrived home from swing shift; he started thinking he should have added more information into their maintenance computer and probably ought to go back to the airport; but he was quite tired and decided to go to bed.Reporter stated there is only one 'Eng GRD/FLT Idle Control' Circuit Breaker located in the flight deck at the Overhead Panel. The C/B will default all three engines to the Flight Idle power position if the C/B opens (pops). Each engine has a Ground (GRD)/Flight (FLT) Idle solenoid installed with four screws on the Main Engine Control (MEC) fuel control; a Cannon plug connects to the solenoid.



Synopsis: A Lead Mechanic was informed he had not provided enough information in the logbook and maintenance computer to explain the cause of an 'Eng Grd/Flt Idle Cont' Circuit Breaker (C/B) to open (pop) on a DC-10 aircraft and justify deferring # 3 Engine's Main Engine Control (MEC) GRD/Flt Idle solenoid. All three engines had defaulted to the Flight Idle mode on landing.