A FOKKER 100 IN CRUISE AT FL350 MADE AN EMER DSCNT DUE TO LOSS OF CABIN PRESSURE IN AUTO AND MANUAL MODES CAUSED BY PRESSURE CTLR AND OUTFLOW VALVE FAILURE.

Narrative

ON APR/ZA/98 WHILE ENRTE MDT TO CLT (FLT XYZ); WE HAD BEGUN A DSCNT FROM FL350 TO FL310; WHEN A LEVEL 3 ALERT SOUNDED; FOLLOWED BY A CABIN ALT WARNING. A CHK OF THE CABIN ALT VERIFIED THAT THE CABIN ALT WAS RISING. OXYGEN MASKS WERE DONNED; CREW COMS WERE ESTABLISHED; AND A DSCNT WAS BEGUN. MANUAL WAS SELECTED ON THE PRESSURE CTLR BUT THE CABIN CONTINUED TO RISE. ATC WAS NOTIFIED AND A DSCNT TO 10000 FT WAS COORDINATED. FLT ATTENDANTS WERE CALLED AND TOLD TO REMAIN SEATED. THE SEAT BELT SIGN WAS ALREADY ILLUMINATED DUE TO PRIOR TURB. FLT ATTENDANTS RPTED NO OBVIOUS EVIDENCE OF DAMAGE. DURING DSCNT; THE CABIN REACHED AN ALT OF 14000 FT; THEREFORE; THE OXYGEN MASKS DID NOT DEPLOY. AFTER REACHING 10000 FT; AS THE ENGS SPOOLED UP; THERE WAS A NOTICEABLE PRESSURE 'BUMP.' PLT OXYGEN MASKS WERE REMOVED. FLT ATTENDANTS RPTED PAX AND CABIN WERE STABLE; AND THAT APPARENTLY THE PAX HAD NOT REALIZED A PROB HAD OCCURRED. AT THIS POINT; WE WERE HANDED OFF FROM ZDC TO GSO APCH DUE TO THE 10000 FT ALT. WE CONTINUED TO CLT WITH A STRAIGHT-IN LNDG ON RWY 23. AS WE TOUCHED DOWN; THERE WAS ANOTHER PRESSURE BUMP. FLT ATTENDANTS CONVEYED SOME PAX REACTION TO THIS PRESSURE BUMP ON LNDG. A PA WAS MADE TO INFORM THE PAX THAT WE HAD HAD A PRESSURIZATION PROB THAT WOULD HAVE TO BE CHKED BY MAINT BEFORE THIS ACFT CONTINUED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A FOKKER 100 AND THE RPT FROM MAINT ON THE CORRECTIVE ACTION WAS REPLACEMENT OF THE CABIN PRESSURE CTLR AND THE L AND R OUTFLOW VALVES.