OXYGEN SVC DOOR LEFT OPEN CAUSES CL65 FLC DIFFICULTIES ON TKOF AND EMER LNDG AT IAD.

Narrative

CREW WAITED FOR LATE INBOUND ACFT. AS ACFT PARKED AT THE GATE MAINT BEGAN A SVC CHK. AFTER MAINT LEFT ACFT WE BOARDED AND PERFORMED PREFLT CHKS. MAINT RETURNED TO ACFT AND KICKED US OUT OF ACFT COCKPIT TO DOWNLOAD ACFT DATA AND PERFORM MINOR REPAIR ON MAIN CABIN DOOR. 20 MINS LATER MAINT FINISHED THE DOOR REPAIR AND RETURNED LOGBOOK. WE BOARDED PAX AND TAXIED TO RWY 30. DURING THE TKOF ROLL AT 100 KTS; AN EFIS COMPARATOR EICAS MESSAGE APPEARED ALONG WITH FO'S AIRSPD READING APPROX 40 KTS LOW COMPARED TO CAPT AND STANDBY INSTS. TKOF WAS CONTINUED DUE TO RWY SURFACE CONDITIONS AND AT ABOUT 160 KTS A LOUD BUZZING SOUND WAS AUDIBLE FOLLOWED BY STALL FAIL AND MACH TRIM FAIL EICAS MESSAGES. QRH PROCS WERE PERFORMED AND THE ACFT RETURNED FOR LNDG. CREW SHOULD NOT HAVE ASSUMED THAT ONLY THE DOOR WAS WORKED ON BY MAINT BECAUSE ANOTHER MECH; WHO SVCED THE OXYGEN WHILE DOOR WORK WAS BEING PERFORMED LEFT THE OXYGEN SVC DOOR OPEN ON THE R SIDE OF THE NOSE. WE ONLY INSPECTED THE CABIN DOOR BEFORE BOARDING. A THOROUGH MAINT BRIEF BY MAINT OR LOGBOOK NOTATION WOULD HAVE ALERTED US TO CHK ACCESS PANELS. A HEADS-UP BY MAINT THAT ANY WORK WAS GOING TO BE PERFORMED BTWN CREWS WOULD HAVE BEEN BETTER AS WE WOULD NOT HAVE ACCEPTED THE ACFT UNTIL THEY FINISHED.