B757-200 FLT CREW NEGLECTS TO SECURE THE ENG AFTER ARR AT THE GATE; DISCOVERED BY OUTBOUND FO.

Narrative

AFTER LNDG WE WERE INFORMED BY RAMP CTL THAT THE RAMP HAD BEEN SHUT DOWN DUE TO LIGHTNING STRIKES ON THE GND AND WERE THEN DIRECTED BY GND CTL TO HOLD IN THE RWY 30 HOLD BLOCK. UPON REACHING THE HOLD BLOCK RAMP CTL REQUESTED THAT WE NOW HOLD ABEAM GATE. WE THEN TAXIED TO THE RAMP. IT WAS AT THIS TIME THAT I REQUESTED THAT THE FO SHUT DOWN THE L ENG INSTEAD OF THE R ENG IN ORDER TO MORE EASILY MAKE THE HARD L TURN INTO THE GATE. RECENT SINGLE ENG TAXI GUIDELINES HAVE RECOMMENDED TAXIING WITH THE R ENG WHEN APPROPRIATE. FOR EXAMPLE; I HAVE MADE IT MY PRACTICE TO START THE R ENG ONLY WHEN I ANTICIPATE A L TURN AFTER SALUTE AND RELEASE FROM GUIDANCE. IN OTHER WORDS; I HAVE RECENTLY BROKEN MY LONG STANDING HABIT OF USING ONLY THE L ENG FOR SINGLE ENG TAXI. WHILE HOLDING ABEAM GATE I TURNED OFF THE FASTEN SEAT BELT SIGN AND MADE AN INFORMATIONAL PA TO THE PAX. BY THE TIME THE RAMP PERSONNEL WERE CLRED TO CONTINUE WORKING THERE WAS A BACKUP OF ACFT WAITING FOR GUIDE MEN AND PUSHBACK CREWS. EVENTUALLY; A SINGLE GUIDE MAN PARKED US AT THE GATE. WHILE WAITING AN EXTENDED PERIOD OF TIME FOR EXTERNAL PWR; THE FO AND MYSELF BEGAN TO PUT AWAY OUR COMMERCIAL CHARTS AND EARPIECES; FILL OUT FLT LOGS AND ENGAGE IN A GENERAL DISCUSSION CONCERNING THE WX CHALLENGES OF THE FLT. IT WAS DURING THIS TIME THAT WE APPARENTLY FAILED TO SHUT DOWN THE R ENG AND PERFORM THE PARKING CHKLIST. I DON'T BELIEVE THAT ACR'S PARKING SOP'S ARE DEFICIENT IN ANY WAY. I BELIEVE THAT OUR ERRORS WERE THE RESULT OF GENERAL CONFUSION ON THE RAMP AND NUMEROUS BREAKS IN THE FLOW OF ROUTINE OPS. ALSO; WHEN THE L ENG IS LEFT RUNNING IT IS MORE APPARENT DUE TO ENG NOISE IN THE JETWAY. SUPPLEMENTAL INFO FROM ACN 703043: RAMP CTL TOLD US TO HOLD ABEAM THE GATE. OPS THEN TOLD US WE STILL HAD SOME TIME BEFORE THE RAMP WAS OFFICIALLY OPEN. THE CAPT SAID TO SHUT DOWN THE L ENG; I HAD PREVIOUSLY SET THE ENG BLEEDS FOR THE R ENG SHUTDOWN; SO I RECONFIGURED FOR A L ENG SHUTDOWN; AND SHUT DOWN THE L ENG. I DON'T REMEMBER HEARING A CALL FOR ENG SHUTDOWN OR THE PARKING CHKLIST. UNFORTUNATELY; TODAY WE HAD MANY NON-STANDARD INTERRUPTIONS TO OUR NORMAL PROCS AND HABIT PATTERNS. WE NEVER CAUGHT THE FACT; THAT WITHOUT THE CUE OF EXTERNAL PWR BEING SUPPLIED OR BEING ASKED TO START THE APU; WE FAILED TO SECURE THE REMAINING ENG. SUPPLEMENTAL INFO FROM ACN 703045: I WENT TO THE GATE TO START PREFLT AND SAW AGENT ON JETWAY AND SHE SAID SHE WAS WAITING FOR A STROLLER. I SAID I WOULD GET IT FOR THEM AND WENT ON RAMP WHERE I SAW THE R ENG WAS STILL RUNNING. I WENT UP THE JETWAY AND TOLD HER ONCE THE ENG WAS SHUT DOWN THE STROLLER WOULD BE OFFLOADED. SHE SAID THAT THERE WAS NO ONE ON BOARD. I WENT TO COCKPIT AND CALLED RAMP ON VHF TO SEE IF MAINT WAS WORKING ON THE ENG AND THEY SAID THEY WOULD CHK. I TOLD THEM I WOULD CALL THEM ON VHF AND I ASKED MAINT IF THEY DO ENG RUN-UPS WITH NO ONE ON BOARD. THEY SAID NO SO I TOLD THEM I WAS SHUTTING DOWN THE R ENG. I DID THAT AND FILLED IN THE CAPT WHEN HE ARRIVED.