Narrative:

Aircraft brought from hangar following maintenance work on avionics. On pushback it was observed that the following annunciator light was illuminated. The captain had the pushback personnel check the tire burst screens in main wheel well area. Ground personnel reported that the tire screens were not installed. Captain decided to continue. Flight departed gate 15 mins late due to previously mentioned maintenance action. The annunciator light was still on. On takeoff a very loud air noise ensued and we could not pressurize. All pressurization controls worked normally; the outflow valve was fully closed. Leveled off at 5000'. Noise was reduced. Burned off fuel for 1 hour, put gear down and the loud air noise returned. Decided that there must be an air leak in nose well. Thought that a nose tire may have burst causing a hold, therefore was made a low approach and the tower reported nothing unusual noted. Had emergency equipment stand by, landed and taxied as normal. It turned out that the east & east compartment door was open. A mechanic had failed to secure the door following maintenance action. I did not see an open door on exterior preflight. Conclusions: multiple chain of events caused incident. I believe the annunciator light on this aircraft is a non standard confign. Aircraft manual and model differences material do not show this particular light. Instead there are 2 different lights: one for the tire screen and the other for equipment (which indicates an open east & east door). If an aircraft does not have tire burst screens, then that light should be removed. It never occurred to us that the light on this aircraft had a dual source. Exterior preflts of doors is not the final check for a secure status. Since doors are routinely opened after preflts, lights are the cockpits final check. We should not have left the ramp with the annunciator light illuminated west/O a log book entry and MEL status. If we had requested this, then a mechanic may have thought to check the east & east door. Supplemental information from acn 142756: contributing factors: this particular lens cover is neither standard nor represented in the pilot aircraft manual or differences handout. The fact that this warning light indicates 2 independent, unrelated conditions was unknown to me.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR MLG UNABLE TO PRESSURIZE AFTER TKOF. ACFT MADE TKOF WITH A WARNING LIGHT ON THAT THE FLT CREW COULD NOT IDENTIFY OR THAT INDICATED A PROBLEM WITH EQUIPMENT NOT ON THE ACFT. POSTFLT INSPECTION REVEALED ELECTRICAL EQUIPMENT ACCESS DOOR OPEN.

Narrative: ACFT BROUGHT FROM HANGAR FOLLOWING MAINT WORK ON AVIONICS. ON PUSHBACK IT WAS OBSERVED THAT THE FOLLOWING ANNUNCIATOR LIGHT WAS ILLUMINATED. THE CAPT HAD THE PUSHBACK PERSONNEL CHK THE TIRE BURST SCREENS IN MAIN WHEEL WELL AREA. GND PERSONNEL RPTED THAT THE TIRE SCREENS WERE NOT INSTALLED. CAPT DECIDED TO CONTINUE. FLT DEPARTED GATE 15 MINS LATE DUE TO PREVIOUSLY MENTIONED MAINT ACTION. THE ANNUNCIATOR LIGHT WAS STILL ON. ON TKOF A VERY LOUD AIR NOISE ENSUED AND WE COULD NOT PRESSURIZE. ALL PRESSURIZATION CONTROLS WORKED NORMALLY; THE OUTFLOW VALVE WAS FULLY CLOSED. LEVELED OFF AT 5000'. NOISE WAS REDUCED. BURNED OFF FUEL FOR 1 HR, PUT GEAR DOWN AND THE LOUD AIR NOISE RETURNED. DECIDED THAT THERE MUST BE AN AIR LEAK IN NOSE WELL. THOUGHT THAT A NOSE TIRE MAY HAVE BURST CAUSING A HOLD, THEREFORE WAS MADE A LOW APCH AND THE TWR RPTED NOTHING UNUSUAL NOTED. HAD EMER EQUIP STAND BY, LANDED AND TAXIED AS NORMAL. IT TURNED OUT THAT THE E & E COMPARTMENT DOOR WAS OPEN. A MECH HAD FAILED TO SECURE THE DOOR FOLLOWING MAINT ACTION. I DID NOT SEE AN OPEN DOOR ON EXTERIOR PREFLT. CONCLUSIONS: MULTIPLE CHAIN OF EVENTS CAUSED INCIDENT. I BELIEVE THE ANNUNCIATOR LIGHT ON THIS ACFT IS A NON STANDARD CONFIGN. ACFT MANUAL AND MODEL DIFFERENCES MATERIAL DO NOT SHOW THIS PARTICULAR LIGHT. INSTEAD THERE ARE 2 DIFFERENT LIGHTS: ONE FOR THE TIRE SCREEN AND THE OTHER FOR EQUIP (WHICH INDICATES AN OPEN E & E DOOR). IF AN ACFT DOES NOT HAVE TIRE BURST SCREENS, THEN THAT LIGHT SHOULD BE REMOVED. IT NEVER OCCURRED TO US THAT THE LIGHT ON THIS ACFT HAD A DUAL SOURCE. EXTERIOR PREFLTS OF DOORS IS NOT THE FINAL CHK FOR A SECURE STATUS. SINCE DOORS ARE ROUTINELY OPENED AFTER PREFLTS, LIGHTS ARE THE COCKPITS FINAL CHK. WE SHOULD NOT HAVE LEFT THE RAMP WITH THE ANNUNCIATOR LIGHT ILLUMINATED W/O A LOG BOOK ENTRY AND MEL STATUS. IF WE HAD REQUESTED THIS, THEN A MECH MAY HAVE THOUGHT TO CHK THE E & E DOOR. SUPPLEMENTAL INFO FROM ACN 142756: CONTRIBUTING FACTORS: THIS PARTICULAR LENS COVER IS NEITHER STANDARD NOR REPRESENTED IN THE PLT ACFT MANUAL OR DIFFERENCES HANDOUT. THE FACT THAT THIS WARNING LIGHT INDICATES 2 INDEPENDENT, UNRELATED CONDITIONS WAS UNKNOWN TO ME.

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.