Narrative:

On jul/fri/98, at approximately XX10 local we departed stl as flight #XXX bound for iah. Right after rotation we had loud wind noise in cockpit and captain and I agreed we must have an access panel open. No lights for door warnings were illuminated on the map panel. We informed departure control we wanted to return to stl. We ran short segment checklists and returned visually to stl runway 30L and made a normal landing. After arriving at the gate it was discovered that our forward equipment and electronics (avionics bay) door had opened. It was also found that the equipment and electronics compartment door light had failed to the closed position so that the light actually worked, but the switch failed so that we had no warning. The light was MEL'ed and the equipment and electronics door was closed and we flew to iah with no further problems. I completed the walkaround prior to the departure of the flight. The only doors I saw open were the forward and aft cargo compartments. Company maintenance had been in the equipment and electronics compartment the previous night to remove a placard on the aircraft. I can only conclude that the door was closed but not properly latched and that I didn't notice it on my walkaround.

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Original NASA ASRS Text

Title: DC9 CREW TOOK OFF WITH THE EQUIP AND ELECTRONIC COMPARTMENT DOOR NOT LOCKED CLOSED. THE DOOR WARNING SWITCH FAILED IN THE CLOSED POS.

Narrative: ON JUL/FRI/98, AT APPROX XX10 LCL WE DEPARTED STL AS FLT #XXX BOUND FOR IAH. RIGHT AFTER ROTATION WE HAD LOUD WIND NOISE IN COCKPIT AND CAPT AND I AGREED WE MUST HAVE AN ACCESS PANEL OPEN. NO LIGHTS FOR DOOR WARNINGS WERE ILLUMINATED ON THE MAP PANEL. WE INFORMED DEP CTL WE WANTED TO RETURN TO STL. WE RAN SHORT SEGMENT CHKLISTS AND RETURNED VISUALLY TO STL RWY 30L AND MADE A NORMAL LNDG. AFTER ARRIVING AT THE GATE IT WAS DISCOVERED THAT OUR FORWARD EQUIP AND ELECTRONICS (AVIONICS BAY) DOOR HAD OPENED. IT WAS ALSO FOUND THAT THE EQUIP AND ELECTRONICS COMPARTMENT DOOR LIGHT HAD FAILED TO THE CLOSED POS SO THAT THE LIGHT ACTUALLY WORKED, BUT THE SWITCH FAILED SO THAT WE HAD NO WARNING. THE LIGHT WAS MEL'ED AND THE EQUIP AND ELECTRONICS DOOR WAS CLOSED AND WE FLEW TO IAH WITH NO FURTHER PROBS. I COMPLETED THE WALKAROUND PRIOR TO THE DEP OF THE FLT. THE ONLY DOORS I SAW OPEN WERE THE FORWARD AND AFT CARGO COMPARTMENTS. COMPANY MAINT HAD BEEN IN THE EQUIP AND ELECTRONICS COMPARTMENT THE PREVIOUS NIGHT TO REMOVE A PLACARD ON THE ACFT. I CAN ONLY CONCLUDE THAT THE DOOR WAS CLOSED BUT NOT PROPERLY LATCHED AND THAT I DIDN'T NOTICE IT ON MY WALKAROUND.

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.