PAX OXYGEN MASKS ARE DEPLOYED AS THE CABIN PRESSURE OF A DC9-30 RISES TO 12000 FT AFTER A PARTIAL LOSS OF PRESSURE AT FL350 ON FREQ WITH ZKC; KC.

Narrative

CREW WAS ENRTE TO MCI AT FL350 FT DEVIATING AROUND TSTM ACTIVITY. APPROX 45 MINS FROM LNDG AT MCI; THE CREW OBSERVED A RED MASTER WARNING LIGHT ILLUMINATE; ALONG WITH A CORRESPONDING RED CABIN PRESSURE ANNUNCIATOR LIGHT. THE CREW THEN CHKED THE CABIN PRESSURE CONTROLLER AND NOTED AN AMBER FLOW LIGHT AND THAT THE CABIN WAS AT 10000 FT AND SLOWLY CLBING. THE CREW ALSO NOTED THAT THE BLUE STANDBY ON AND XFER LOCKOUT LIGHTS WERE ILLUMINATED. THE CREW THEN PERFORMED THE MEMORY ITEMS FOR A CABIN PRESSURE LOSS; REQUESTED A DSCNT FROM ATC FOR OPERATIONAL PURPOSES; AND CONSULTED THE QRH FOR ADDITIONAL GUIDANCE. ATC COMPLIED WITH OUR REQUEST FOR A DSCNT; GAVE US A TURN; AND STARTED US DOWN. AT THIS POINT; THE #1 FLT ATTENDANT INFORMED US THAT THE MASKS HAD 'DROPPED' IN THE CABIN. WHEN TIME PERMITTED; I MADE A PA TO THE PAX EXPLAINING THE SIT AND INSTRUCTING THEM TO REMOVE THEIR OXYGEN MASKS. AT NO TIME DID THE CABIN ALT EXCEED 12000 FT. THE UTILIZATION OF CRM TECHNIQUES DURING THIS SIT AIDED THE CREW IN ACHIEVING THE SUCCESSFUL OUTCOME. SUPPLEMENTAL INFO FROM ACN 587586: AS THE CABIN WAS CLBING SLOWLY APPROX 500 FPM; WE DID A RAPID DSCNT; BUT NOT AN EMER DSCNT. AS WE DSNDED; WE REGAINED PRESSURIZATION AND LEVELED OFF AT 10000 FT. CABIN ALT REACHED A MAX OF 12000 FT. FLT CONTINUED TO MCI AT 10000 FT.