Narrative:

This was the fourth day of my first trip after IOE requalification on the DC9. As I always do, I looked at the door warning lights before reporting 'door warning lights out' to the ground crew on pushback, and when responding to the first officer's challenges of 'annunciator panel' during the after start and before takeoff checklists. I never saw an 'electric compartment door' light illuminated. After takeoff we realized immediately that the aircraft was not pressurizing, even though the air supply switches were on and the outflow valve closed. It was then that the first officer noticed the electric compartment door light on. We turned downwind and made a normal landing just below maximum gross weight. Maintenance could not find any malfunction with the light switch, but we did note that this particular door light was much dimmer than the other door lights, even in the 'bright' position. In the morning light, at the angle I was looking, it could easily be missed. We both learned from this the importance of testing these lights every time we respond to a checklist addressing them. This should become standard procedure on these old airplanes with such discrepancies in warning light brightness.

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Original NASA ASRS Text

Title: ELECTRIC COMPARTMENT LIGHT NOT SEEN BY FLC ON 2 CHKLISTS. AFTER TKOF ACFT WOULDN'T PRESSURIZE DUE TO OPEN DOOR. FLC RETURNED AND LANDED TO HAVE DOOR CLOSED.

Narrative: THIS WAS THE FOURTH DAY OF MY FIRST TRIP AFTER IOE REQUALIFICATION ON THE DC9. AS I ALWAYS DO, I LOOKED AT THE DOOR WARNING LIGHTS BEFORE RPTING 'DOOR WARNING LIGHTS OUT' TO THE GND CREW ON PUSHBACK, AND WHEN RESPONDING TO THE FO'S CHALLENGES OF 'ANNUNCIATOR PANEL' DURING THE AFTER START AND BEFORE TKOF CHKLISTS. I NEVER SAW AN 'ELECTRIC COMPARTMENT DOOR' LIGHT ILLUMINATED. AFTER TKOF WE REALIZED IMMEDIATELY THAT THE ACFT WAS NOT PRESSURIZING, EVEN THOUGH THE AIR SUPPLY SWITCHES WERE ON AND THE OUTFLOW VALVE CLOSED. IT WAS THEN THAT THE FO NOTICED THE ELECTRIC COMPARTMENT DOOR LIGHT ON. WE TURNED DOWNWIND AND MADE A NORMAL LNDG JUST BELOW MAX GROSS WT. MAINT COULD NOT FIND ANY MALFUNCTION WITH THE LIGHT SWITCH, BUT WE DID NOTE THAT THIS PARTICULAR DOOR LIGHT WAS MUCH DIMMER THAN THE OTHER DOOR LIGHTS, EVEN IN THE 'BRIGHT' POS. IN THE MORNING LIGHT, AT THE ANGLE I WAS LOOKING, IT COULD EASILY BE MISSED. WE BOTH LEARNED FROM THIS THE IMPORTANCE OF TESTING THESE LIGHTS EVERY TIME WE RESPOND TO A CHKLIST ADDRESSING THEM. THIS SHOULD BECOME STANDARD PROC ON THESE OLD AIRPLANES WITH SUCH DISCREPANCIES IN WARNING LIGHT BRIGHTNESS.

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.