MD-80 Series (DC-9-80) Undifferentiated or Other Model
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Aircraft
After departing observed 2 blue lights on pressurization controller. Controller was successfully reset by Captain. Flow gauges and position of outflow valve were normal. Climbing through approximately 18;000 observed 'cabin altitude warning'. Cabin Altitude warning/rapid depressurization red box was followed; cabin had climbed to 11;000 and started down with accomplishment of red box. First Officer flew aircraft to 8;000 and entered holding to burn off fuel. Captain declared emergency and landed aircraft at [diversion airport]. Maintenance determined both primary and secondary controllers had failed.
After accomplishing a normal takeoff; the automatic pressurization system STDBY ON and TRANSFER LOCKOUT lights illuminated approaching 5;000 FT MSL. I leveled the aircraft at 5;000 FT while the Captain investigated the anomaly. The Captain cycled the system selector switch to PRIMARY and the STDBY ON light extinguished; indicating the PRIMARY system was again operational. He then switched it back to STDBY. He then pressed the TRANSFER LOCKOUT light to reset the automatic transfer. The light extinguished. Departure Control gave a clearance to climb and handed us over to Center who gave us a climb to FL230. Passing FL180 during the climb the MASTER WARNING and CABIN ALT lights illuminated. We donned oxygen masks and the Captain immediately followed the memory items for Cabin Altitude Warning/Rapid Depressurization (CABIN ALT CONTROL LEVER-MANUAL (DOWN) and OUTFLOW VALVE-FULL FORWARD and MANUALLY LOCKED). I smoothly initiated an immediate Emergency Descent while coordinating with Center for a lower altitude. During the descent we accomplished the rest of the QRH procedures and decided to divert. By using manual pressurization the cabin did not get above 10;500 FT. Once we leveled at 6;000 FT we coordinated to hold to burn off fuel down to maximum landing weight. That took about 30 minutes and gave us ample time to stabilize cabin pressure and differential pressure. The Captain made an uneventful approach and landing while I controlled pressurization manually. Once we arrived at the gate maintenance troubleshot the automatic pressurization system. They found it completely inoperative. They deferred it and we coordinated with Dispatch to continue to destination at FL240 using Manual Pressurization Control procedures in accordance with MEL 21-23b and the QRH. During this flight the Captain flew and I controlled pressurization manually. The flight was uneventful safely bringing most of our original passengers with us.
MD82 flight crew experienced pressurization anomalies during initial climb which were corrected then total failure passing through FL180. Oxygen masks are donned and an emergency descent initiated with manual control of pressurization established during descent. The crew diverts and Maintenance defers the pressurization system and the flight is dispatched to the original destination with the First Officer controlling the manual pressurization.