Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 304
Workload; Time Pressure; Human-Machine Interface; Communication Breakdown; Distraction
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Returned To Gate; General Maintenance Action
Human Factors
While completing the Before Takeoff Checklist; we noticed during Recall; ENG annunciation indicating EEC's were in ALTN mode. We pulled over to complete the QRH procedure. Captain spoke with Maintenance and was advised to taxi back to gate. Maintenance was called out to the aircraft and noticed an error during the BITE test and the EEC's switches were pushed out.Although schedule pressures were involved; my Captain and I used [risk management] to purposely take our time running checklists. During the Before Start/Originating Checklist; when I read the checklist item referring to EECs; I know I looked up at the EECs while Captain responded; and I thought I observed an ON indication. The plastic cover was scratched and hazy and I may have overlooked it. To prevent this in the future; I will take extra time and attention in ensuring switches are in the correct position before moving on to the next item.
After starting #2 engine; ENG alert displayed and we noted EECs in ALTN mode. Ran QRH and then called Maintenance and discussed deferral versus return to gate. During this discussion; we noted that EEC switches were pushed out (versus pushed in or ON). After discussing further with Maintenance; the decision was made to return to the gate. When Maintenance arrived; we agreed that the EEC switches may have been left in the ALT position and were in that position when the aircraft was towed to the gate (it had been remotely parked).Due to a late RSV (Reserve) callout (one hour prior to show) and very heavy traffic en route from home; I arrived to find the aircraft completely boarded and waiting for my arrival. FO (First Officer) had arrived prior to me and was helpful and professional and ready to go. We recognized the potential for time pressure to cause us to rush and even verbalized the need to be careful and methodical. However; in performing the Before Start Checklist; it is possible that we failed to notice that the EEC switches were not in the ON position; despite the fact that we both remember looking up at it when performing the checklist. This is due to the fact that the plastic covers were cloudy and scratched and the amber ALTN annunciation would not appear until after engine start. You must look closely to determine that the white ON circle appears in the switch. In the future; I plan to look VERY closely at this switch to avoid this issue again. However; I think there should be some type of review to determine how they were left there.
B737-700 flight crew reported returning to the gate because the EEC switches were in the alternate position.