Narrative:

My captain and I climbed to 17000 ft MSL unpressurized. A visual check of the pressurization knob (3 position lever) falsely confirmed that 'pressurization was checked and set,' per our checklist. A physical manual check of the lever would have verified its position, which was 'dump.' also, more emphasis on a physical check of the lever's position during initial flight training would help prevent the problem in the future. We experienced mild hypoxia, and received a clearance to 9000 MSL. Factors that contributed to not noticing our cabin altitude include: preoccupation with communication with company in order to be re-released to lga after 2 missed approachs at elm. A very gradual climb out while waiting for our new release: we didn't notice the cabin pressure physically. An inoperative cabin altitude warning system. It didn't work! Supplemental information from acn 254834: factors involved, which though small, I feel they contributed to the unsafe situation. First, the aircraft, being an originator at a maintenance base, was late coming from the hangar. There was a problem with low idle on one of the engines. Because of the mechanics being pressured for time, I feel the pressurization switch, which caused our problem later in the morning, was not reset to its normal position. The mechanics do morning run-ups and this system, after testing, was probably not reset. In our haste, as a crew trying to make up for lost time, we obviously overlooked the switch. I started to feel uncomfortable physically as we climbed through 15000 ft. After leveling at 17000 ft, I still felt terrible. After looking the instruments over, I realized, along with the first officer, that we were unpressurized. The first officer immediately asked for lower altitude. We descended to 9000 ft and continued to lga without further incident.

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Original NASA ASRS Text

Title: COMMUTER FLC CLBS TO 17000 FT WITHOUT PRESSURIZATION.

Narrative: MY CAPT AND I CLBED TO 17000 FT MSL UNPRESSURIZED. A VISUAL CHK OF THE PRESSURIZATION KNOB (3 POS LEVER) FALSELY CONFIRMED THAT 'PRESSURIZATION WAS CHKED AND SET,' PER OUR CHKLIST. A PHYSICAL MANUAL CHK OF THE LEVER WOULD HAVE VERIFIED ITS POS, WHICH WAS 'DUMP.' ALSO, MORE EMPHASIS ON A PHYSICAL CHK OF THE LEVER'S POS DURING INITIAL FLT TRAINING WOULD HELP PREVENT THE PROB IN THE FUTURE. WE EXPERIENCED MILD HYPOXIA, AND RECEIVED A CLRNC TO 9000 MSL. FACTORS THAT CONTRIBUTED TO NOT NOTICING OUR CABIN ALT INCLUDE: PREOCCUPATION WITH COM WITH COMPANY IN ORDER TO BE RE-RELEASED TO LGA AFTER 2 MISSED APCHS AT ELM. A VERY GRADUAL CLBOUT WHILE WAITING FOR OUR NEW RELEASE: WE DIDN'T NOTICE THE CABIN PRESSURE PHYSICALLY. AN INOP CABIN ALT WARNING SYS. IT DIDN'T WORK! SUPPLEMENTAL INFO FROM ACN 254834: FACTORS INVOLVED, WHICH THOUGH SMALL, I FEEL THEY CONTRIBUTED TO THE UNSAFE SIT. FIRST, THE ACFT, BEING AN ORIGINATOR AT A MAINT BASE, WAS LATE COMING FROM THE HANGAR. THERE WAS A PROB WITH LOW IDLE ON ONE OF THE ENGS. BECAUSE OF THE MECHS BEING PRESSURED FOR TIME, I FEEL THE PRESSURIZATION SWITCH, WHICH CAUSED OUR PROB LATER IN THE MORNING, WAS NOT RESET TO ITS NORMAL POS. THE MECHS DO MORNING RUN-UPS AND THIS SYS, AFTER TESTING, WAS PROBABLY NOT RESET. IN OUR HASTE, AS A CREW TRYING TO MAKE UP FOR LOST TIME, WE OBVIOUSLY OVERLOOKED THE SWITCH. I STARTED TO FEEL UNCOMFORTABLE PHYSICALLY AS WE CLBED THROUGH 15000 FT. AFTER LEVELING AT 17000 FT, I STILL FELT TERRIBLE. AFTER LOOKING THE INSTS OVER, I REALIZED, ALONG WITH THE FO, THAT WE WERE UNPRESSURIZED. THE FO IMMEDIATELY ASKED FOR LOWER ALT. WE DSNDED TO 9000 FT AND CONTINUED TO LGA WITHOUT FURTHER INCIDENT.

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.