Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 315; Flight Crew Type 14000
Situational Awareness; Distraction; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented; Flight Crew Returned To Gate
Aircraft; Procedure; Human Factors
Inoperative APU; second flight of the day; on time;  started the number one engine at gate; cleared equipment; pushed from the gate; asked for taxi to remote area for crossbleed start of number two engine. Stopping at designated location; the aircraft began to slightly shimmy under braking. I stopped braking then applied brakes again; shimmy did not happen again so I set the parking brake. I then grabbed the number one engine start lever and began to shut the number one engine down. Realizing what I was doing; I quickly returned it to the previous position but the engine had already shut down. We were now on battery power. I told the Flight Attendants to remain seated; then told ATC we would need a tow back to the gate and we had one radio and would need to go off frequency to coordinate with Operations. We turned IRS one and two off; and tried to explain to the Passengers what had happened. We were back at the gate in approximately 10 minutes. Started the engine and did the procedure properly the second time. The remainder of the flight was uneventful.I guess I would say it was muscle memory; the same motion as arriving at a gate; number two engine shut down; Parking brake set. I should be more deliberate in all of my actions; but it happened so fast that the FO did not even have time to react. The brake shimmy was a distraction; but that does not excuse me from my action.
This was a mistake. I didn't expect to see it once; I don't expect to see it again.
A B737-700 Captain intending to crossbleed start #2 engine from #1 bleed air; instead shut down #1 engine. With the APU inoperative; the aircraft was towed back to the gate for a second start.