Narrative:

Performed an aircraft walk around preflight inspection. All areas including doors appeared normal and secure. I returned to cockpit, performed procedures for pre-departure duties. Prior to engine start a newark based mechanic came up to flight deck, looked at logbook and stated that he had also done preflight inspection and all appeared ok to him. Start, taxi was all normal. Checks for door lights out was made. Takeoff was normal, lift off and after takeoff procedures went west/O incidence until approximately 2500-3000' AGL when I observed caution light and a/C light and automatic-fail light. I placed a/C controller southwest to standby position and informed captain of pressurization problem. At 3500' climbing to 5000' we observed equipment door light intermittently flashing. At 5000' it was obvious that aircraft would not pressurize. Captain decision was made to return to ewr. Captain advised newark control, no emergency was being declared and they vectored aircraft to final approach to ILS on runway 22L. After shutdown several mechanics entered flight and stated that equipment door was open. They then checked door and fastener and placed mechanic inside compartment to close door from inside and reported door then securely shut. Flight was redispatched and flown to montego bay and back with no further problem. I suggest a close inspection of all medium large transport equipment. Door fasteners for any unusual wear or warping. Also have mechanics close equipment door from inside until a fix is found.

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Original NASA ASRS Text

Title: ACR MLG RETURN LAND WHEN EQUIPMENT DOOR WAS DISCOVERED OPEN AFTER TKOF.

Narrative: PERFORMED AN ACFT WALK AROUND PREFLT INSPECTION. ALL AREAS INCLUDING DOORS APPEARED NORMAL AND SECURE. I RETURNED TO COCKPIT, PERFORMED PROCS FOR PRE-DEP DUTIES. PRIOR TO ENG START A NEWARK BASED MECH CAME UP TO FLT DECK, LOOKED AT LOGBOOK AND STATED THAT HE HAD ALSO DONE PREFLT INSPECTION AND ALL APPEARED OK TO HIM. START, TAXI WAS ALL NORMAL. CHKS FOR DOOR LIGHTS OUT WAS MADE. TKOF WAS NORMAL, LIFT OFF AND AFTER TKOF PROCS WENT W/O INCIDENCE UNTIL APPROX 2500-3000' AGL WHEN I OBSERVED CAUTION LIGHT AND A/C LIGHT AND AUTO-FAIL LIGHT. I PLACED A/C CTLR SW TO STANDBY POS AND INFORMED CAPT OF PRESSURIZATION PROB. AT 3500' CLBING TO 5000' WE OBSERVED EQUIP DOOR LIGHT INTERMITTENTLY FLASHING. AT 5000' IT WAS OBVIOUS THAT ACFT WOULD NOT PRESSURIZE. CAPT DECISION WAS MADE TO RETURN TO EWR. CAPT ADVISED NEWARK CTL, NO EMER WAS BEING DECLARED AND THEY VECTORED ACFT TO FINAL APCH TO ILS ON RWY 22L. AFTER SHUTDOWN SEVERAL MECHS ENTERED FLT AND STATED THAT EQUIP DOOR WAS OPEN. THEY THEN CHKED DOOR AND FASTENER AND PLACED MECH INSIDE COMPARTMENT TO CLOSE DOOR FROM INSIDE AND RPTED DOOR THEN SECURELY SHUT. FLT WAS REDISPATCHED AND FLOWN TO MONTEGO BAY AND BACK WITH NO FURTHER PROB. I SUGGEST A CLOSE INSPECTION OF ALL MLG EQUIP. DOOR FASTENERS FOR ANY UNUSUAL WEAR OR WARPING. ALSO HAVE MECHS CLOSE EQUIP DOOR FROM INSIDE UNTIL A FIX IS FOUND.

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.