Narrative:

Departed saf to den. An IFR clearance was obtained in the air with ZAB and the flight was cleared to FL220. Climbing through 17500 ft I noticed the cabin had not pressurized and we did not get the cabin annunciator (cabin altitude high) in the cockpit. (Usually this annunciator would illuminate when cabin altitude goes above 12500 ft.) my copilot did not notice the aircraft was not pressurizing on the out of 10000 ft MSL checklist which states 'pressurization set and checked.' I was the PF and she was doing the checklists as PNF. I advised abq that I had a pressurization problem, I needed lower, I was VFR and I will cancel out the IFR and stay with him for VFR advisories to denver. I started my descent and abq declared an emergency for me. I stated we were not in an emergency situation. He stated that he declared an emergency because he had conflicting traffic and that he did not receive our IFR cancellation. He did say he had many other aircraft on frequency and that my transmission might have been blocked. We had a visual with other traffic and stated so 'traffic in sight.' I again stated that we were VFR, descending, cancel out instruments, VFR to denver request flight following. There is no emergency. My actions were quick and decisive. I needed to descend as quickly as possible. Contributing factors were frequency congestion on ZAB, communication problems between me and center. The flight continued on to denver at 9500 ft VFR. The aircraft was written up in denver for maintenance. Aircraft would not pressurize, cabin altitude high annunciator fails to illuminate in flight. Descent from 17500 ft to 9500 ft took less than 90 seconds. Supplemental information from acn 344533: told the controller we were descending to 14000 ft MSL. Controller said to maintain 17000 ft MSL. Originally we were on an IFR flight plan and clearance. Other xmissions were exchanged and we continued beyond 17000 ft to 14000 ft. I was the PNF and up until the problem, the radios were handled by myself. The captain was the PF and took over the radios and took over the whole situation.

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Original NASA ASRS Text

Title: LTT DSNDS WITHOUT CLRNC DUE TO PRESSURIZATION PROB.

Narrative: DEPARTED SAF TO DEN. AN IFR CLRNC WAS OBTAINED IN THE AIR WITH ZAB AND THE FLT WAS CLRED TO FL220. CLBING THROUGH 17500 FT I NOTICED THE CABIN HAD NOT PRESSURIZED AND WE DID NOT GET THE CABIN ANNUNCIATOR (CABIN ALT HIGH) IN THE COCKPIT. (USUALLY THIS ANNUNCIATOR WOULD ILLUMINATE WHEN CABIN ALT GOES ABOVE 12500 FT.) MY COPLT DID NOT NOTICE THE ACFT WAS NOT PRESSURIZING ON THE OUT OF 10000 FT MSL CHKLIST WHICH STATES 'PRESSURIZATION SET AND CHKED.' I WAS THE PF AND SHE WAS DOING THE CHKLISTS AS PNF. I ADVISED ABQ THAT I HAD A PRESSURIZATION PROB, I NEEDED LOWER, I WAS VFR AND I WILL CANCEL OUT THE IFR AND STAY WITH HIM FOR VFR ADVISORIES TO DENVER. I STARTED MY DSCNT AND ABQ DECLARED AN EMER FOR ME. I STATED WE WERE NOT IN AN EMER SIT. HE STATED THAT HE DECLARED AN EMER BECAUSE HE HAD CONFLICTING TFC AND THAT HE DID NOT RECEIVE OUR IFR CANCELLATION. HE DID SAY HE HAD MANY OTHER ACFT ON FREQ AND THAT MY XMISSION MIGHT HAVE BEEN BLOCKED. WE HAD A VISUAL WITH OTHER TFC AND STATED SO 'TFC IN SIGHT.' I AGAIN STATED THAT WE WERE VFR, DSNDING, CANCEL OUT INSTS, VFR TO DENVER REQUEST FLT FOLLOWING. THERE IS NO EMER. MY ACTIONS WERE QUICK AND DECISIVE. I NEEDED TO DSND AS QUICKLY AS POSSIBLE. CONTRIBUTING FACTORS WERE FREQ CONGESTION ON ZAB, COM PROBS BTWN ME AND CTR. THE FLT CONTINUED ON TO DENVER AT 9500 FT VFR. THE ACFT WAS WRITTEN UP IN DENVER FOR MAINT. ACFT WOULD NOT PRESSURIZE, CABIN ALT HIGH ANNUNCIATOR FAILS TO ILLUMINATE IN FLT. DSCNT FROM 17500 FT TO 9500 FT TOOK LESS THAN 90 SECONDS. SUPPLEMENTAL INFO FROM ACN 344533: TOLD THE CTLR WE WERE DSNDING TO 14000 FT MSL. CTLR SAID TO MAINTAIN 17000 FT MSL. ORIGINALLY WE WERE ON AN IFR FLT PLAN AND CLRNC. OTHER XMISSIONS WERE EXCHANGED AND WE CONTINUED BEYOND 17000 FT TO 14000 FT. I WAS THE PNF AND UP UNTIL THE PROB, THE RADIOS WERE HANDLED BY MYSELF. THE CAPT WAS THE PF AND TOOK OVER THE RADIOS AND TOOK OVER THE WHOLE SIT.

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.