Narrative:

Event: flew a 45 min flight with 1 door/slide-chute not properly armed for emergency evacuate/evacuation. After pushback, prior to taxi out of milwaukee's general mitchell field on jun/mon/89 at about xa, 2 door lights were still on at doors 3L and 3R. The second officer called the F/a's on the interphone at those doors and told them the lights were still on. Door 3L light then went out. The second officer left the cockpit and went to 3R to see what the problem was. Shortly thereafter, he returned to the cockpit and said that he had operated the door open to close twice and it operated normally. He suggested that we return to the ramp. I said 'if we just have a door-light not working properly, that it was probably 'ok' to depart', and to 'check the book'. I neglected to ask him if the door was arming properly. (On this model of the widebody transport the cockpit door-indication system lights go out when the respective cabin doors are properly closed and armed for emergency, chute evacuate/evacuation). We together checked the MEL and found that 1 door light may be inoperative, if the door was visually checked to be closed. We both missed the door arming requirement, which we should have known. However, this requirement was referred to in this section of the procedure as a 'check' paragraph XXXX while we were in the lights 'not operating properly' section. In other words, our area of concern was with the light not working and even though we missed the arming function, we would have probably caught our error if it had stated, for example: 'if door visually checked closed and chute armed, departure was allowed with 1 door light indication not operating properly.' the procedure, in effect, assumed that we knew of the arming requirement, but I feel that it should have been stated as was the 'door closed properly' was stated, rather than via a paragraph reference item. The flight operated normally from milwaukee to minneapolis-st paul int'l airport. The WX and airport conditions were excellent at both airports, as well as en route. Our crew had brought the same aircraft in the previous night. After arriving at minneapolis-st paul and talking with the maintenance people, did we then discern the possible ramifications of the flight with the door chute not correctly armed. A contributing factor was the problem initially with both doors 3L and 3R, which started me on the erroneous path of not believing the light indications and looking for a problem with the lights and the F/a procedures, rather than really investigating the problem and subsequently overlooking the fact that we might have a valid maintenance problem.

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Original NASA ASRS Text

Title: MEL MISINTERPRETED. FLT CONDUCTED WITH 1 CABIN DOOR EMERGENCY SYSTEM APPARENTLY NOT ARMED.

Narrative: EVENT: FLEW A 45 MIN FLT WITH 1 DOOR/SLIDE-CHUTE NOT PROPERLY ARMED FOR EMER EVAC. AFTER PUSHBACK, PRIOR TO TAXI OUT OF MILWAUKEE'S GENERAL MITCHELL FIELD ON JUN/MON/89 AT ABOUT XA, 2 DOOR LIGHTS WERE STILL ON AT DOORS 3L AND 3R. THE S/O CALLED THE F/A'S ON THE INTERPHONE AT THOSE DOORS AND TOLD THEM THE LIGHTS WERE STILL ON. DOOR 3L LIGHT THEN WENT OUT. THE S/O LEFT THE COCKPIT AND WENT TO 3R TO SEE WHAT THE PROBLEM WAS. SHORTLY THEREAFTER, HE RETURNED TO THE COCKPIT AND SAID THAT HE HAD OPERATED THE DOOR OPEN TO CLOSE TWICE AND IT OPERATED NORMALLY. HE SUGGESTED THAT WE RETURN TO THE RAMP. I SAID 'IF WE JUST HAVE A DOOR-LIGHT NOT WORKING PROPERLY, THAT IT WAS PROBABLY 'OK' TO DEPART', AND TO 'CHECK THE BOOK'. I NEGLECTED TO ASK HIM IF THE DOOR WAS ARMING PROPERLY. (ON THIS MODEL OF THE WDB THE COCKPIT DOOR-INDICATION SYSTEM LIGHTS GO OUT WHEN THE RESPECTIVE CABIN DOORS ARE PROPERLY CLOSED AND ARMED FOR EMER, CHUTE EVAC). WE TOGETHER CHECKED THE MEL AND FOUND THAT 1 DOOR LIGHT MAY BE INOP, IF THE DOOR WAS VISUALLY CHECKED TO BE CLOSED. WE BOTH MISSED THE DOOR ARMING REQUIREMENT, WHICH WE SHOULD HAVE KNOWN. HOWEVER, THIS REQUIREMENT WAS REFERRED TO IN THIS SECTION OF THE PROC AS A 'CHECK' PARAGRAPH XXXX WHILE WE WERE IN THE LIGHTS 'NOT OPERATING PROPERLY' SECTION. IN OTHER WORDS, OUR AREA OF CONCERN WAS WITH THE LIGHT NOT WORKING AND EVEN THOUGH WE MISSED THE ARMING FUNCTION, WE WOULD HAVE PROBABLY CAUGHT OUR ERROR IF IT HAD STATED, FOR EXAMPLE: 'IF DOOR VISUALLY CHECKED CLOSED AND CHUTE ARMED, DEP WAS ALLOWED WITH 1 DOOR LIGHT INDICATION NOT OPERATING PROPERLY.' THE PROC, IN EFFECT, ASSUMED THAT WE KNEW OF THE ARMING REQUIREMENT, BUT I FEEL THAT IT SHOULD HAVE BEEN STATED AS WAS THE 'DOOR CLOSED PROPERLY' WAS STATED, RATHER THAN VIA A PARAGRAPH REFERENCE ITEM. THE FLT OPERATED NORMALLY FROM MILWAUKEE TO MINNEAPOLIS-ST PAUL INT'L ARPT. THE WX AND ARPT CONDITIONS WERE EXCELLENT AT BOTH ARPTS, AS WELL AS ENRTE. OUR CREW HAD BROUGHT THE SAME ACFT IN THE PREVIOUS NIGHT. AFTER ARRIVING AT MINNEAPOLIS-ST PAUL AND TALKING WITH THE MAINT PEOPLE, DID WE THEN DISCERN THE POSSIBLE RAMIFICATIONS OF THE FLT WITH THE DOOR CHUTE NOT CORRECTLY ARMED. A CONTRIBUTING FACTOR WAS THE PROBLEM INITIALLY WITH BOTH DOORS 3L AND 3R, WHICH STARTED ME ON THE ERRONEOUS PATH OF NOT BELIEVING THE LIGHT INDICATIONS AND LOOKING FOR A PROBLEM WITH THE LIGHTS AND THE F/A PROCS, RATHER THAN REALLY INVESTIGATING THE PROBLEM AND SUBSEQUENTLY OVERLOOKING THE FACT THAT WE MIGHT HAVE A VALID MAINT PROBLEM.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.