Narrative:

I am writing about a pressurization problem on mar/xa/00 on the flight from day to iad. The aircraft was xyz and we began the flight with the right environmental control system bleed MEL'ed. As we were climbing through approximately FL180, we noticed a blue advisory message 'left and right pack inoperative' and that the cabin altitude was climbing at a greater rate than normal. We stopped our climb and pulled up the environmental control system page which indicated that our only bleed had closed. I informed ATC of the problem and requested a lower altitude, in which they gave us 11000 ft. Shortly thereafter, we got an amber 'left pack fail' cas message and an overheat condition was on the environmental control system page. Although the QRH didn't directly address this problem while operating on 1 bleed source, we followed it as closely as possible and the environmental control system began working again. Even though the pressurization problem was resolved, we called maintenance and dispatch to inform them. Dispatch confirmed that our fuel was sufficient to continue to iad at 11000 ft. In addition, maintenance wanted us to recycle the left hx fan on the ground in iad. Upon arrival in iad, I called maintenance on the telephone to touch base and to let them know that everything was operating normally. After the initial problem, we never experienced anymore abnormalities with the environmental control system. We flew the aircraft 3 more legs with no further problems.

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Original NASA ASRS Text

Title: A DORNIER 328 CLBING THROUGH FL180 HAD THE L AIR CONDITIONING PACK FAIL, R PACK PREVIOUSLY DEFERRED AS INOP, DSNDED TO 11000 FT DUE TO CABIN CLBING.

Narrative: I AM WRITING ABOUT A PRESSURIZATION PROB ON MAR/XA/00 ON THE FLT FROM DAY TO IAD. THE ACFT WAS XYZ AND WE BEGAN THE FLT WITH THE R ENVIRONMENTAL CTL SYS BLEED MEL'ED. AS WE WERE CLBING THROUGH APPROX FL180, WE NOTICED A BLUE ADVISORY MESSAGE 'L AND R PACK INOP' AND THAT THE CABIN ALT WAS CLBING AT A GREATER RATE THAN NORMAL. WE STOPPED OUR CLB AND PULLED UP THE ENVIRONMENTAL CTL SYS PAGE WHICH INDICATED THAT OUR ONLY BLEED HAD CLOSED. I INFORMED ATC OF THE PROB AND REQUESTED A LOWER ALT, IN WHICH THEY GAVE US 11000 FT. SHORTLY THEREAFTER, WE GOT AN AMBER 'L PACK FAIL' CAS MESSAGE AND AN OVERHEAT CONDITION WAS ON THE ENVIRONMENTAL CTL SYS PAGE. ALTHOUGH THE QRH DIDN'T DIRECTLY ADDRESS THIS PROB WHILE OPERATING ON 1 BLEED SOURCE, WE FOLLOWED IT AS CLOSELY AS POSSIBLE AND THE ENVIRONMENTAL CTL SYS BEGAN WORKING AGAIN. EVEN THOUGH THE PRESSURIZATION PROB WAS RESOLVED, WE CALLED MAINT AND DISPATCH TO INFORM THEM. DISPATCH CONFIRMED THAT OUR FUEL WAS SUFFICIENT TO CONTINUE TO IAD AT 11000 FT. IN ADDITION, MAINT WANTED US TO RECYCLE THE L HX FAN ON THE GND IN IAD. UPON ARR IN IAD, I CALLED MAINT ON THE TELEPHONE TO TOUCH BASE AND TO LET THEM KNOW THAT EVERYTHING WAS OPERATING NORMALLY. AFTER THE INITIAL PROB, WE NEVER EXPERIENCED ANYMORE ABNORMALITIES WITH THE ENVIRONMENTAL CTL SYS. WE FLEW THE ACFT 3 MORE LEGS WITH NO FURTHER PROBS.

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.