Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Workload; Confusion
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Human Factors
With both engines running and the Before Takeoff Checklist complete; we approached the hold line for Runway 9L. The Captain stopped the aircraft at the hold line and inadvertently shut down the number two engine; [intending to set] the parking brake. I did not see this happen because shortly after we stopped; the Tower cleared us for takeoff and I was busy responding to the radio call with my attention outside to clear final and verify we were turning onto Runway 9L. While applying power and slowly turning onto the active runway to line up for takeoff; the Captain stated that the number two generator had gone offline which I verified on the overhead panel. I immediately looked at the engine gages and observed zero percent N1 on the number two engine; informed the Captain the number two was not running; and radioed the Tower we needed to exit the runway at Taxiway T. We exited at Taxiway T at normal taxi speed; got back in line on Taxiway M; analyzed and discussed what had just happened; started the number two engine; did our flows; ran the Before Takeoff Checklist and departed uneventfully.
A B737 Captain stopped to hold short of the takeoff runway and meant to set the parking brake but instead shutdown number two engine just before takeoff clearance was issued.