Narrative:

While working on the ram air actuator in the l-hand air conditioning bay; I opened the nose east&east compartment door several times to test the system by pushing in the ground sense button. I forgot to close the door after the last time testing it. Contributing factors: WX -- cold/wind. Comments: just a lapse in memory while trying to get done and back in a warm environment. Supplemental information from acn 643364: the first officer called me to the aircraft. He told me that on his walkaround he saw the east&east door was open. I went to check the door to see if the door was closed -- it was. I gave him a thumbs up; he returned the thumbs up. (Aircraft returned to departure station; unable to pressure. Forward east&east compartment door was discovered open. Door warning system for this door location was determined to be inoperative.) contributing factors: there was a lot of ice on the ground; so I was looking down so as not to slip and fall. Supplemental information from acn 643361: just after takeoff; the aircraft would not pressurize. There was a loud 'air' noise below the cockpit -- as if the forward equipment door was open. We returned to den after running all of our checklists. We limited our altitude to 10000 ft and speed to 220 KTS while running the checklists. Upon gate return; we wrote up the problem. Maintenance found the forward equipment door unsecured. The warning light in cockpit was not illuminated for the equipment door; even though the light tested ok when we did a light test. Since the forward equipment door warning system was obviously not working (as we found out after the fact); we were not sure what the problem was after takeoff. So a number of things went wrong to all come together to cause our air return. We wrote up the forward equipment door warning light system also. Maintenance found the system would not illuminate when the door was opened.

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Original NASA ASRS Text

Title: A B737-300; UNABLE TO PRESSURIZE INFLT; RETURNED WITH THE E&E COMPARTMENT DOOR NOT CLOSED WHILE THE DOOR OPENED WARNING SYS HAD ALSO FAILED.

Narrative: WHILE WORKING ON THE RAM AIR ACTUATOR IN THE L-HAND AIR CONDITIONING BAY; I OPENED THE NOSE E&E COMPARTMENT DOOR SEVERAL TIMES TO TEST THE SYS BY PUSHING IN THE GND SENSE BUTTON. I FORGOT TO CLOSE THE DOOR AFTER THE LAST TIME TESTING IT. CONTRIBUTING FACTORS: WX -- COLD/WIND. COMMENTS: JUST A LAPSE IN MEMORY WHILE TRYING TO GET DONE AND BACK IN A WARM ENVIRONMENT. SUPPLEMENTAL INFO FROM ACN 643364: THE FO CALLED ME TO THE ACFT. HE TOLD ME THAT ON HIS WALKAROUND HE SAW THE E&E DOOR WAS OPEN. I WENT TO CHK THE DOOR TO SEE IF THE DOOR WAS CLOSED -- IT WAS. I GAVE HIM A THUMBS UP; HE RETURNED THE THUMBS UP. (ACFT RETURNED TO DEP STATION; UNABLE TO PRESSURE. FORWARD E&E COMPARTMENT DOOR WAS DISCOVERED OPEN. DOOR WARNING SYS FOR THIS DOOR LOCATION WAS DETERMINED TO BE INOP.) CONTRIBUTING FACTORS: THERE WAS A LOT OF ICE ON THE GND; SO I WAS LOOKING DOWN SO AS NOT TO SLIP AND FALL. SUPPLEMENTAL INFO FROM ACN 643361: JUST AFTER TKOF; THE ACFT WOULD NOT PRESSURIZE. THERE WAS A LOUD 'AIR' NOISE BELOW THE COCKPIT -- AS IF THE FORWARD EQUIP DOOR WAS OPEN. WE RETURNED TO DEN AFTER RUNNING ALL OF OUR CHKLISTS. WE LIMITED OUR ALT TO 10000 FT AND SPD TO 220 KTS WHILE RUNNING THE CHKLISTS. UPON GATE RETURN; WE WROTE UP THE PROB. MAINT FOUND THE FORWARD EQUIP DOOR UNSECURED. THE WARNING LIGHT IN COCKPIT WAS NOT ILLUMINATED FOR THE EQUIP DOOR; EVEN THOUGH THE LIGHT TESTED OK WHEN WE DID A LIGHT TEST. SINCE THE FORWARD EQUIP DOOR WARNING SYS WAS OBVIOUSLY NOT WORKING (AS WE FOUND OUT AFTER THE FACT); WE WERE NOT SURE WHAT THE PROB WAS AFTER TKOF. SO A NUMBER OF THINGS WENT WRONG TO ALL COME TOGETHER TO CAUSE OUR AIR RETURN. WE WROTE UP THE FORWARD EQUIP DOOR WARNING LIGHT SYS ALSO. MAINT FOUND THE SYS WOULD NOT ILLUMINATE WHEN THE DOOR WAS OPENED.

Data retrieved from NASA's ASRS site as of January 2009 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.