Narrative:

After pwrback, we were informed by ramp that our upper beacon was inoperative. We consulted the MEL 33-07 which stated that at least 1 or both beacons could be inoperative provided all strobes were operable. The strobes were turned on and verified operable by ramp. I, as the captain, elected to proceed as this item is flight crew placardable. There is a requirement for notification to dispatch, which we did via ACARS. Additionally, dispatch has a requirement to not authority/authorized night operations with a beacon out. We were still in daylight conditions. Although it was still light outside we did not know what the time of official twilight was until we asked dispatch. MEL states daytime flts authority/authorized. MEL 33-07 states for day and night operations. I believed I was legal to continue.

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Original NASA ASRS Text

Title: A FOKKER 100. AFTER PUSHBACK THE CAPT DEFERS, PER THE MEL, THE UPPER BEACON BUT HAS CONFLICT WITH THE DISPATCHER OVER OFFICIAL DAYLIGHT.

Narrative: AFTER PWRBACK, WE WERE INFORMED BY RAMP THAT OUR UPPER BEACON WAS INOP. WE CONSULTED THE MEL 33-07 WHICH STATED THAT AT LEAST 1 OR BOTH BEACONS COULD BE INOP PROVIDED ALL STROBES WERE OPERABLE. THE STROBES WERE TURNED ON AND VERIFIED OPERABLE BY RAMP. I, AS THE CAPT, ELECTED TO PROCEED AS THIS ITEM IS FLC PLACARDABLE. THERE IS A REQUIREMENT FOR NOTIFICATION TO DISPATCH, WHICH WE DID VIA ACARS. ADDITIONALLY, DISPATCH HAS A REQUIREMENT TO NOT AUTH NIGHT OPS WITH A BEACON OUT. WE WERE STILL IN DAYLIGHT CONDITIONS. ALTHOUGH IT WAS STILL LIGHT OUTSIDE WE DID NOT KNOW WHAT THE TIME OF OFFICIAL TWILIGHT WAS UNTIL WE ASKED DISPATCH. MEL STATES DAYTIME FLTS AUTH. MEL 33-07 STATES FOR DAY AND NIGHT OPS. I BELIEVED I WAS LEGAL TO CONTINUE.

Data retrieved from NASA's ASRS site as of July 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.