Narrative:

I picked up aircraft for flight in stl. Maintenance was working on a pressurization problem that had been written up on the incoming flight. Following is the write up in the logbook: 'outflow valve indication/manual pressure control wheel rotates back and forth continuously 2-3 inches. Pressurization indicates normal.' a standby controller was placard inoperative and the aircraft was released by maintenance with one automatic controller. After referring to the MEL we continued preparing for departure. Passenger load was 74 and 1 jump seat rider. The jump seat rider was mr X of the FAA. Mr X requested our certificates. I asked mr X about his familiarity with the MD80 flight deck oxygen, interphone and jump seat procedures. Mr X responded that he was familiar with the aircraft. The flight departed stl on schedule. Before leaving the gate, I mentioned to the first officer the need to watch pressurization during initial climb out. During initial climb out, pressurization was working normally. Climbing through 10000 ft, the cabin pressure checked normal. During our climb to 27000 ft, the manual control wheel started to continuously rotate back and forth a couple of inches. Cabin altitude was climbing at a normal rate. We leveled off at 27000 ft, the cabin was stabilized. To stop the manual control wheel from rotating back and forth, I had the first officer refer to the manual pressurization checklist in the QRH. After moving the pressurization control lever to manual, the cabin altitude started to climb immediately, so the first officer manually tried to close the outflow valve. The cabin altitude continued to climb, so we donned our oxygen masks and requested a lower altitude from ATC. We began our descent to 24000 ft. The first officer referred to the QRH for cabin pressure loss procedures. I flew the aircraft and the first officer addressed the pressurization problem. Before reaching 24000 ft, we were cleared to 17000 ft. With the throttles closed, the cabin altitude started to climb at a greater rate than before. The vmo clacker sounded a few seconds during our descent. The cabin altitude light came on at 10000 ft, and before the aircraft had leveled off, the oxygen masks had dropped in the cabin. At 10000 ft, the automatic controller was back in automatic, the cabin pressure was under control, and by all indications was working normally. I talked to the purser and made a PA announcement to the crew and passenger informing them of what had occurred and that the cabin pressure was stabilized. I informed the flight attendants that oxygen was no longer needed and released them to check the passenger. I then contacted dispatch and told him about our situation, position and altitude. I asked about diverting to pit. I also requested a new flight plan to lga at 17000 ft. I again talked with the flight attendant about the situation in the cabin and was told that everyone seemed fine. I made a second PA announcement to the passenger assuring them that the situation was under control. Very shortly thereafter, I received a new flight plan from dispatch to lga. This plan showed fuel remaining at lga to be 4500 pounds. With this new information regarding remaining fuel quantity and with regard to our passenger safety, I told ATC and dispatch that we wanted to divert to pit. Crew and passenger were informed of the decision to divert to pit. All checklists were completed and a normal approach and landing was made at pit. Passenger were deplaned and reprotected on another flight to new york. Pressurization automatic controller, cabin oxygen masks, and flight deck oxygen were written up in the aircraft logbook. I remained with the aircraft for 2 1/2 hours and was then released to return to domicile. Supplemental information from acn 522209: at approximately 15000 ft the pressure control wheel began to oscillate back and forth, though the pressure remained normal. The captain said we would level at 15000 ft and see if the controller would stabilize. I asked the captain if he wanted me to control the pressurization manually, and that I had done this before on the DC9. The captain said that since the pressure was normal, we would stay in automatic. After a few mins at 15000 ft the pressure control wheel stopped oscillating and the pressure schedule remained normal. As we continued our climb with the pressurization schedule progressing normally, the pressure control wheel began to oscillate again. After moving the pressure control lever down to the manual position the cabin started to climb. I immediately rolled the control wheel forward to close the outflow valve. While the valve indicator was moving forward the cabin continued to climb. I then positioned the control lever back to the automatic position in an attempt to stop the cabin from climbing. This had no effect and the captain said to request a lower altitude. I placed the pressure controller back to manual and rolled the control wheel full forward to close the outflow valve. As we were descending the cabin climbed through 10000 ft. The air traffic controller asked if we were declaring an emergency and I said affirmative we are unable to hold cabin pressure.

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Original NASA ASRS Text

Title: MD82 CREW LOST CABIN PRESSURIZATION IN ZID CLASS A.

Narrative: I PICKED UP ACFT FOR FLT IN STL. MAINT WAS WORKING ON A PRESSURIZATION PROB THAT HAD BEEN WRITTEN UP ON THE INCOMING FLT. FOLLOWING IS THE WRITE UP IN THE LOGBOOK: 'OUTFLOW VALVE INDICATION/MANUAL PRESSURE CTL WHEEL ROTATES BACK AND FORTH CONTINUOUSLY 2-3 INCHES. PRESSURIZATION INDICATES NORMAL.' A STANDBY CTLR WAS PLACARD INOP AND THE ACFT WAS RELEASED BY MAINT WITH ONE AUTO CTLR. AFTER REFERRING TO THE MEL WE CONTINUED PREPARING FOR DEP. PAX LOAD WAS 74 AND 1 JUMP SEAT RIDER. THE JUMP SEAT RIDER WAS MR X OF THE FAA. MR X REQUESTED OUR CERTIFICATES. I ASKED MR X ABOUT HIS FAMILIARITY WITH THE MD80 FLT DECK OXYGEN, INTERPHONE AND JUMP SEAT PROCS. MR X RESPONDED THAT HE WAS FAMILIAR WITH THE ACFT. THE FLT DEPARTED STL ON SCHEDULE. BEFORE LEAVING THE GATE, I MENTIONED TO THE FO THE NEED TO WATCH PRESSURIZATION DURING INITIAL CLBOUT. DURING INITIAL CLBOUT, PRESSURIZATION WAS WORKING NORMALLY. CLBING THROUGH 10000 FT, THE CABIN PRESSURE CHKED NORMAL. DURING OUR CLB TO 27000 FT, THE MANUAL CTL WHEEL STARTED TO CONTINUOUSLY ROTATE BACK AND FORTH A COUPLE OF INCHES. CABIN ALT WAS CLBING AT A NORMAL RATE. WE LEVELED OFF AT 27000 FT, THE CABIN WAS STABILIZED. TO STOP THE MANUAL CTL WHEEL FROM ROTATING BACK AND FORTH, I HAD THE FO REFER TO THE MANUAL PRESSURIZATION CHKLIST IN THE QRH. AFTER MOVING THE PRESSURIZATION CTL LEVER TO MANUAL, THE CABIN ALT STARTED TO CLB IMMEDIATELY, SO THE FO MANUALLY TRIED TO CLOSE THE OUTFLOW VALVE. THE CABIN ALT CONTINUED TO CLB, SO WE DONNED OUR OXYGEN MASKS AND REQUESTED A LOWER ALT FROM ATC. WE BEGAN OUR DSCNT TO 24000 FT. THE FO REFERRED TO THE QRH FOR CABIN PRESSURE LOSS PROCS. I FLEW THE ACFT AND THE FO ADDRESSED THE PRESSURIZATION PROB. BEFORE REACHING 24000 FT, WE WERE CLRED TO 17000 FT. WITH THE THROTTLES CLOSED, THE CABIN ALT STARTED TO CLB AT A GREATER RATE THAN BEFORE. THE VMO CLACKER SOUNDED A FEW SECONDS DURING OUR DSCNT. THE CABIN ALT LIGHT CAME ON AT 10000 FT, AND BEFORE THE ACFT HAD LEVELED OFF, THE OXYGEN MASKS HAD DROPPED IN THE CABIN. AT 10000 FT, THE AUTO CTLR WAS BACK IN AUTO, THE CABIN PRESSURE WAS UNDER CTL, AND BY ALL INDICATIONS WAS WORKING NORMALLY. I TALKED TO THE PURSER AND MADE A PA ANNOUNCEMENT TO THE CREW AND PAX INFORMING THEM OF WHAT HAD OCCURRED AND THAT THE CABIN PRESSURE WAS STABILIZED. I INFORMED THE FLT ATTENDANTS THAT OXYGEN WAS NO LONGER NEEDED AND RELEASED THEM TO CHK THE PAX. I THEN CONTACTED DISPATCH AND TOLD HIM ABOUT OUR SIT, POS AND ALT. I ASKED ABOUT DIVERTING TO PIT. I ALSO REQUESTED A NEW FLT PLAN TO LGA AT 17000 FT. I AGAIN TALKED WITH THE FLT ATTENDANT ABOUT THE SIT IN THE CABIN AND WAS TOLD THAT EVERYONE SEEMED FINE. I MADE A SECOND PA ANNOUNCEMENT TO THE PAX ASSURING THEM THAT THE SIT WAS UNDER CTL. VERY SHORTLY THEREAFTER, I RECEIVED A NEW FLT PLAN FROM DISPATCH TO LGA. THIS PLAN SHOWED FUEL REMAINING AT LGA TO BE 4500 LBS. WITH THIS NEW INFO REGARDING REMAINING FUEL QUANTITY AND WITH REGARD TO OUR PAX SAFETY, I TOLD ATC AND DISPATCH THAT WE WANTED TO DIVERT TO PIT. CREW AND PAX WERE INFORMED OF THE DECISION TO DIVERT TO PIT. ALL CHKLISTS WERE COMPLETED AND A NORMAL APCH AND LNDG WAS MADE AT PIT. PAX WERE DEPLANED AND REPROTECTED ON ANOTHER FLT TO NEW YORK. PRESSURIZATION AUTO CTLR, CABIN OXYGEN MASKS, AND FLT DECK OXYGEN WERE WRITTEN UP IN THE ACFT LOGBOOK. I REMAINED WITH THE ACFT FOR 2 1/2 HRS AND WAS THEN RELEASED TO RETURN TO DOMICILE. SUPPLEMENTAL INFO FROM ACN 522209: AT APPROX 15000 FT THE PRESSURE CTL WHEEL BEGAN TO OSCILLATE BACK AND FORTH, THOUGH THE PRESSURE REMAINED NORMAL. THE CAPT SAID WE WOULD LEVEL AT 15000 FT AND SEE IF THE CTLR WOULD STABILIZE. I ASKED THE CAPT IF HE WANTED ME TO CTL THE PRESSURIZATION MANUALLY, AND THAT I HAD DONE THIS BEFORE ON THE DC9. THE CAPT SAID THAT SINCE THE PRESSURE WAS NORMAL, WE WOULD STAY IN AUTO. AFTER A FEW MINS AT 15000 FT THE PRESSURE CTL WHEEL STOPPED OSCILLATING AND THE PRESSURE SCHEDULE REMAINED NORMAL. AS WE CONTINUED OUR CLB WITH THE PRESSURIZATION SCHEDULE PROGRESSING NORMALLY, THE PRESSURE CTL WHEEL BEGAN TO OSCILLATE AGAIN. AFTER MOVING THE PRESSURE CTL LEVER DOWN TO THE MANUAL POS THE CABIN STARTED TO CLB. I IMMEDIATELY ROLLED THE CTL WHEEL FORWARD TO CLOSE THE OUTFLOW VALVE. WHILE THE VALVE INDICATOR WAS MOVING FORWARD THE CABIN CONTINUED TO CLB. I THEN POSITIONED THE CTL LEVER BACK TO THE AUTO POS IN AN ATTEMPT TO STOP THE CABIN FROM CLBING. THIS HAD NO EFFECT AND THE CAPT SAID TO REQUEST A LOWER ALT. I PLACED THE PRESSURE CTLR BACK TO MANUAL AND ROLLED THE CTL WHEEL FULL FORWARD TO CLOSE THE OUTFLOW VALVE. AS WE WERE DSNDING THE CABIN CLBED THROUGH 10000 FT. THE AIR TFC CTLR ASKED IF WE WERE DECLARING AN EMER AND I SAID AFFIRMATIVE WE ARE UNABLE TO HOLD CABIN PRESSURE.

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.