Commercial Fixed Wing
Communication Breakdown; Distraction; Workload; Troubleshooting
Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Human Factors; MEL
[The aircraft] had a status message on the EICAS screen (Fuel QTY CHANNEL). Upon troubleshooting the system; we discovered that the circuit breaker FUEL QTY 1 on the P11 panel was tripped and would not reset. Troubleshooting further per the FIM (Fault Isolation Manual) a bite check on the fuel quantity processor displayed a channel 1 fault code D1; which is a densitometer fault. Channel 2 system checked ok. At this time I wanted to defer channel 1 but Maintenance Controller said we could not because of the D1 fault; that we had to defer the densitometer. I believe that in the several phone conversation that I had with Maintenance Control; he did not hear me say that per the MEL for deferring the densitometer it was required to pull 4 circuit breakers; then go and [remove the connector from the densitometer]; then go back and reset those 4 circuit breakers. The FUEL QTY 1 Circuit Breaker would not reset so I decided to go back and defer channel 1 [of the fuel quantity indication system] which requires the FUEL QTY 1 Circuit Breaker to be pulled and collared. [We] were very busy that night. We had three other deferred maintenance items that were being issued that night on aircraft very close to departure time. [We] were handling all four deferred maintenance items and there was lots of activity and probably some confusion that busy night. [It was a] very busy night for one [Maintenance Controller] and one [Maintenance Technician] to handle four aircraft at the same time and try to get them out on time. Also [I am] still training my self and getting use to using the EFB [Electronic Flight Bag]. The EFB is a good computer but is very finger sensitive when trying to move thru the MEL quickly.
A Maintenance Technician reported difficulty in troubleshooting a complex aircraft system as well as communicating the condition to the Maintenance Controller.  This led to confusion on the MEL that was to be applied.