Narrative:

On taxi out of cle, left pack duct overheated and pack tripped. Reset by SOP. Came back again. Reset by SOP, contacted maintenance dispatch, redispatched single pack operation (left pack off). Normal takeoff and climb. Cabin altitude seemed to work ok. Passing 18000 ft, noticed excessive cabin altitude, immediately followed by cabin altitude warning horn. Captain shallowed climb and asked if I could control cabin, my response, 'standby, manual AC and dc outflow valve closed. No!' asked for and received a descent to 10000 ft. Masks deployed during descent, cabin continued to climb. Flight attendants said passenger complained of not receiving oxygen. Captain told me to pull oxygen handle, I complied. Flight attendants reported 1 passenger with a history of respiratory problems, having difficulties. A medical doctor was on board attended to her needs. Still difficulty maintaining cabin altitude. Captain requested descent to 8000 ft. Cabin rate still not right, minimal airflow, captain directs left pack on, cabin stabilized, pack operations normal. We tried to contact dispatch, they can hear us but can't hear them. They want us to communicate with them via ACARS, workload doesn't permit. We ask ATC for priority handling and to relay message to company, they complied. Had ambulance meet aircraft at ord. Approach and landing to ord uneventful. Corrective actions and causal factors: pay more attention to cabin pressurization, particularly with single pack operation. My focus first 10000 ft is outside the cockpit, altitude and engine instruments. Another factor, maintenance discovered pressure leak around cargo door. This leak wouldn't be a factor with 2 pack operations, but with single pack operations that's an altogether different story. Human factors: a XC30 departure out of cle equates to a XA30 departure for a den base crew. Callback conversation with reporter revealed the following information: the reporter flies the B727-200. This aircraft has only 2 packs and air sources. The APU is unavailable in-flight. The aircraft was properly dispatched with one pack inoperative. On the ground, the air carrier found that the aircraft could pressurize to no more than 2.5 pounds per square inch vice the normal 8 pounds per square inch. This was caused by one or more door leaks. Had both air sources been operating, the reporter believes that there would have been enough airflow to overcome the door leaks. Paramedics met the aircraft at the gate. The reporter does not know the extent of the injury/discomfort to the passenger. The door leaks and pressurization have been fixed and the aircraft is back in service.

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Original NASA ASRS Text

Title: AN ACR B727-200 HAD A PRESSURIZATION PROB THAT REQUIRED OXYGEN TO BE DELIVERED TO THE PAX. THERE WAS A PAX INJURY, 1 PAX SUFFERED RESPIRATORY PROBS REQUIRING MEDICAL AID. ACFT EQUIP PROB CARGO DOOR LEAK OR LEAKS, OXYGEN MASKS WERE PRESENTED BUT THERE WAS NO FLOW, L PACK DUCT OVERHEAT WITH PACK TRIP.

Narrative: ON TAXI OUT OF CLE, L PACK DUCT OVERHEATED AND PACK TRIPPED. RESET BY SOP. CAME BACK AGAIN. RESET BY SOP, CONTACTED MAINT DISPATCH, REDISPATCHED SINGLE PACK OP (L PACK OFF). NORMAL TKOF AND CLB. CABIN ALT SEEMED TO WORK OK. PASSING 18000 FT, NOTICED EXCESSIVE CABIN ALT, IMMEDIATELY FOLLOWED BY CABIN ALT WARNING HORN. CAPT SHALLOWED CLB AND ASKED IF I COULD CTL CABIN, MY RESPONSE, 'STANDBY, MANUAL AC AND DC OUTFLOW VALVE CLOSED. NO!' ASKED FOR AND RECEIVED A DSCNT TO 10000 FT. MASKS DEPLOYED DURING DSCNT, CABIN CONTINUED TO CLB. FLT ATTENDANTS SAID PAX COMPLAINED OF NOT RECEIVING OXYGEN. CAPT TOLD ME TO PULL OXYGEN HANDLE, I COMPLIED. FLT ATTENDANTS RPTED 1 PAX WITH A HISTORY OF RESPIRATORY PROBS, HAVING DIFFICULTIES. A MEDICAL DOCTOR WAS ON BOARD ATTENDED TO HER NEEDS. STILL DIFFICULTY MAINTAINING CABIN ALT. CAPT REQUESTED DSCNT TO 8000 FT. CABIN RATE STILL NOT RIGHT, MINIMAL AIRFLOW, CAPT DIRECTS L PACK ON, CABIN STABILIZED, PACK OPS NORMAL. WE TRIED TO CONTACT DISPATCH, THEY CAN HEAR US BUT CAN'T HEAR THEM. THEY WANT US TO COMMUNICATE WITH THEM VIA ACARS, WORKLOAD DOESN'T PERMIT. WE ASK ATC FOR PRIORITY HANDLING AND TO RELAY MESSAGE TO COMPANY, THEY COMPLIED. HAD AMBULANCE MEET ACFT AT ORD. APCH AND LNDG TO ORD UNEVENTFUL. CORRECTIVE ACTIONS AND CAUSAL FACTORS: PAY MORE ATTN TO CABIN PRESSURIZATION, PARTICULARLY WITH SINGLE PACK OP. MY FOCUS FIRST 10000 FT IS OUTSIDE THE COCKPIT, ALT AND ENG INSTS. ANOTHER FACTOR, MAINT DISCOVERED PRESSURE LEAK AROUND CARGO DOOR. THIS LEAK WOULDN'T BE A FACTOR WITH 2 PACK OPS, BUT WITH SINGLE PACK OPS THAT'S AN ALTOGETHER DIFFERENT STORY. HUMAN FACTORS: A XC30 DEP OUT OF CLE EQUATES TO A XA30 DEP FOR A DEN BASE CREW. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES THE B727-200. THIS ACFT HAS ONLY 2 PACKS AND AIR SOURCES. THE APU IS UNAVAILABLE INFLT. THE ACFT WAS PROPERLY DISPATCHED WITH ONE PACK INOP. ON THE GND, THE ACR FOUND THAT THE ACFT COULD PRESSURIZE TO NO MORE THAN 2.5 LBS PER SQUARE INCH VICE THE NORMAL 8 LBS PER SQUARE INCH. THIS WAS CAUSED BY ONE OR MORE DOOR LEAKS. HAD BOTH AIR SOURCES BEEN OPERATING, THE RPTR BELIEVES THAT THERE WOULD HAVE BEEN ENOUGH AIRFLOW TO OVERCOME THE DOOR LEAKS. PARAMEDICS MET THE ACFT AT THE GATE. THE RPTR DOES NOT KNOW THE EXTENT OF THE INJURY/DISCOMFORT TO THE PAX. THE DOOR LEAKS AND PRESSURIZATION HAVE BEEN FIXED AND THE ACFT IS BACK IN SVC.

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.