A B757-200 PLT DEPLOYED THE ACFT'S 1R EVAC SLIDE WHILE ATTEMPTING TO VIEW RAMP CARGO LOADING PROGRESS THROUGH THE 1R DOOR.

Narrative

CAPT ACCIDENTALLY DEPLOYED EVAC SLIDE AT DOOR 1R. WAS ATTEMPTING TO ASSESS PROGRESS OF BAG LOADING AT 1 HR INTO A PUSHBACK DELAY. HAD OPENED SAME DOOR 30 MINS PRIOR TO MAKE EARLIER ASSESSMENT BEFORE JETWAY WAS PULLED AWAY AND DOORS ARMED FOR DEP. ON THIS ATTEMPT; FAILED TO CHK POS OF ARMING LEVER; LIGHT; AND POP-OUT INDICATOR BEFORE REOPENING IT. WAS MENTALLY STILL TREATING IT AS AN UNARMED DOOR; MISTAKENLY. AFTER MOVING THE DOOR LEVER AND INITIATING DEPLOYMENT; I RECEIVED A VERBAL WARNING FROM A NEARBY FLT ATTENDANT; BUT THE DOOR HAD ALREADY STARTED TO DEPLOY. LEADING UP TO THE EVENT; I HAD ATTEMPTED TO USE THE FO'S WINDOW AND THE REFLECTIONS IN THE TERMINAL WINDOW BUT THEY DID NOT OFFER SATISFACTORY VIEWS OF THE LOADING AREA. THE INTENTION OF MAKING VISUAL OBSERVATIONS WAS TO ADDRESS WHAT WAS NEEDED TO EXPEDITE OUR DEP. WE HAD RECEIVED SEVERAL EXPLANATIONS FROM RAMP CTL ON THE RADIO INCLUDING: CONNECTING PAX; CONNECTING BAGS; AND RAMP MANPOWER SHORTAGE. I FELT THE NEED TO CLARIFY WHAT WAS ACTUALLY HAPPENING ON THE RAMP SO WE COULD GET WHAT WAS NEEDED TO DEPART. LUCKILY; NO PEOPLE OR EQUIP WERE IN THE SLIDE'S PATH AND THERE WERE NO INJURIES OUTSIDE OR INSIDE THE ACFT AND THERE WAS NO EQUIP DAMAGED.