Narrative:

While cruising at FL350; we got 'automatic pressurization fail' EICAS message. The cabin quickly started to depressurize. An immediate call to ATC asked for a descent which was initiated by the PF. ATC cleared us for the descent within 5-10 seconds. An emergency was not declared. There is a chance that we might have left our altitude prior to the clearance. The manual procedure was completed while in the descent. The cabin quickly stabilized and returned to normal. The descent was continued to FL250 in case the issue would deteriorate. Upon leveling at FL250 and realizing that the cabin pressure would hold fine; I again referred to the manual to ensure that all steps in the manual had been complied with. The automatic pressurization controller should have been better marked; as we had problems identing which push button was the automatic/manual and which was the dump button. Due to our seated positions; the marking was shadowed -- covered by dirt and unable to be read. A quick call to maintenance control informed us which push button to push and the manual pressurization was used for the remainder of the flight. It was not initially clear if we had a rapid depressurization or only an automatic pressurization failure. The rapid change in cabin pressure first made me believe that there was a rapid depressurization. The aom procedure was complied with; but after a descent was initiated. A call to ATC was requested; and I contacted ATC after landing. The ATC manager had listened to our conversation and mentioned that if we needed an immediate descent we should have declared an emergency. I agreed but mentioned that I did not think that a descent was initiated prior to receiving the clearance from ATC. He confirmed that he had not reviewed this either. His comment was only made based on our statement that we would be initiating a descent prior to receiving the clearance. There were no other aircraft in our vicinity and no further action would be taken from ATC. The location of the automatic pressurization controller in this specific aircraft was located far aft on the console. The distance from the controller head to the panel rim in front of the controller was very small. This leaves a small gap between the 2 panels. This gap was full of dirt and made it hard to identify that there was anything written in this gap. Looking from our seated position in this small gap; we were unable to realize that there was anything written on the controller to identify the automatic/manual and dump push buttons. I referred to the manual to see if it had a picture of the pressurization controller to help us identify the buttons. I would suggest that small gaps be routinely cleaned by maintenance and that a pictorial of important items like this controller be included in the manual or MEL for reference by the flight crew. Looking back at the sequence of the event; the prudent thing to do would be to immediately treat it as a rapid depressurization; declare an emergency.

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Original NASA ASRS Text

Title: CRJ700 CAPTAIN REPORTS 'AUTO PRESSURIZATION FAIL' AT FL350 AND CLIMBING CABIN ALTITUDE. DESCENT IS INITIATED WITH ATC APPROVAL AND CONTROL OF THE CABIN IS REGAINED DURING THE DESCENT TO FL250. DIFFICULTIES WERE ENCOUNTERED READING THE LABELS ON THE PRESSURIZATION CONTROL PANEL DUE TO DIRT.

Narrative: WHILE CRUISING AT FL350; WE GOT 'AUTO PRESSURIZATION FAIL' EICAS MESSAGE. THE CABIN QUICKLY STARTED TO DEPRESSURIZE. AN IMMEDIATE CALL TO ATC ASKED FOR A DSCNT WHICH WAS INITIATED BY THE PF. ATC CLRED US FOR THE DSCNT WITHIN 5-10 SECONDS. AN EMER WAS NOT DECLARED. THERE IS A CHANCE THAT WE MIGHT HAVE LEFT OUR ALT PRIOR TO THE CLRNC. THE MANUAL PROC WAS COMPLETED WHILE IN THE DSCNT. THE CABIN QUICKLY STABILIZED AND RETURNED TO NORMAL. THE DSCNT WAS CONTINUED TO FL250 IN CASE THE ISSUE WOULD DETERIORATE. UPON LEVELING AT FL250 AND REALIZING THAT THE CABIN PRESSURE WOULD HOLD FINE; I AGAIN REFERRED TO THE MANUAL TO ENSURE THAT ALL STEPS IN THE MANUAL HAD BEEN COMPLIED WITH. THE AUTO PRESSURIZATION CONTROLLER SHOULD HAVE BEEN BETTER MARKED; AS WE HAD PROBS IDENTING WHICH PUSH BUTTON WAS THE AUTO/MANUAL AND WHICH WAS THE DUMP BUTTON. DUE TO OUR SEATED POSITIONS; THE MARKING WAS SHADOWED -- COVERED BY DIRT AND UNABLE TO BE READ. A QUICK CALL TO MAINT CTL INFORMED US WHICH PUSH BUTTON TO PUSH AND THE MANUAL PRESSURIZATION WAS USED FOR THE REMAINDER OF THE FLT. IT WAS NOT INITIALLY CLEAR IF WE HAD A RAPID DEPRESSURIZATION OR ONLY AN AUTO PRESSURIZATION FAILURE. THE RAPID CHANGE IN CABIN PRESSURE FIRST MADE ME BELIEVE THAT THERE WAS A RAPID DEPRESSURIZATION. THE AOM PROC WAS COMPLIED WITH; BUT AFTER A DSCNT WAS INITIATED. A CALL TO ATC WAS REQUESTED; AND I CONTACTED ATC AFTER LNDG. THE ATC MGR HAD LISTENED TO OUR CONVERSATION AND MENTIONED THAT IF WE NEEDED AN IMMEDIATE DSCNT WE SHOULD HAVE DECLARED AN EMER. I AGREED BUT MENTIONED THAT I DID NOT THINK THAT A DSCNT WAS INITIATED PRIOR TO RECEIVING THE CLRNC FROM ATC. HE CONFIRMED THAT HE HAD NOT REVIEWED THIS EITHER. HIS COMMENT WAS ONLY MADE BASED ON OUR STATEMENT THAT WE WOULD BE INITIATING A DSCNT PRIOR TO RECEIVING THE CLRNC. THERE WERE NO OTHER ACFT IN OUR VICINITY AND NO FURTHER ACTION WOULD BE TAKEN FROM ATC. THE LOCATION OF THE AUTO PRESSURIZATION CONTROLLER IN THIS SPECIFIC ACFT WAS LOCATED FAR AFT ON THE CONSOLE. THE DISTANCE FROM THE CONTROLLER HEAD TO THE PANEL RIM IN FRONT OF THE CONTROLLER WAS VERY SMALL. THIS LEAVES A SMALL GAP BTWN THE 2 PANELS. THIS GAP WAS FULL OF DIRT AND MADE IT HARD TO IDENT THAT THERE WAS ANYTHING WRITTEN IN THIS GAP. LOOKING FROM OUR SEATED POSITION IN THIS SMALL GAP; WE WERE UNABLE TO REALIZE THAT THERE WAS ANYTHING WRITTEN ON THE CONTROLLER TO IDENT THE AUTO/MANUAL AND DUMP PUSH BUTTONS. I REFERRED TO THE MANUAL TO SEE IF IT HAD A PICTURE OF THE PRESSURIZATION CONTROLLER TO HELP US IDENT THE BUTTONS. I WOULD SUGGEST THAT SMALL GAPS BE ROUTINELY CLEANED BY MAINT AND THAT A PICTORIAL OF IMPORTANT ITEMS LIKE THIS CONTROLLER BE INCLUDED IN THE MANUAL OR MEL FOR REF BY THE FLT CREW. LOOKING BACK AT THE SEQUENCE OF THE EVENT; THE PRUDENT THING TO DO WOULD BE TO IMMEDIATELY TREAT IT AS A RAPID DEPRESSURIZATION; DECLARE AN EMER.

Data retrieved from NASA's ASRS site as of May 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.