DC9-50 CREW WAS NOT ABLE TO CTL CABIN ALT AND MADE A RAPID DSCNT TO 10000 FT.

Narrative

UNEVENTFUL CLB TO FL330. PRESSURIZATION SYS SEEMED TO BE OPERATING NORMALLY. NOTICED R AIR CONDITIONING TEMP HIGHER THAN NORMAL. MADE ADJUSTMENTS TO 'BAL' TEMP WITH L AIR CONDITIONING SYS. SHORT TIME LATER; CABIN PRESSURE ANNUNCIATOR LIGHT ILLUMINATED. CONFIRMED CABIN PRESSURE INDICATING 10000 FT. BEGAN IMMEDIATE DSCNT WITH IMMEDIATE COORD WITH ATC WHILE FO ACCOMPLISHED CABIN PRESSURE LOSS/RAPID DSCNT CHKLIST. NOTED PRESSURIZATION OUTFLOW VALVE ALREADY INDICATED FULL CLOSED. CABIN OXYGEN MASKS DEPLOYED AUTOMATICALLY AT BEGINNING OF DSCNT. AFTER LEVELOFF AT 10000 FT; COMMUNICATED WITH FLT ATTENDANT TO CONFIRM STATUS OF CABIN. NO FURTHER PROBS INDICATED. CONTACTED DISPATCH. CONFIRMED ADEQUATE FUEL TO CONTINUE TO DEST AT 10000 FT WITH APPLICABLE RESERVES. AT 10000 FT; R AIR CONDITIONING WAS NORMALLY FUNCTIONAL. SUSPECT HIGHER THAN NORMAL TEMP AT FL330 INDICATED MOMENTARY LOSS OF R PACK; ALLOWING SLOW CABIN CLB. NO EXPLANATION FOR MORE PRONOUNCED INDICATIONS; IE; RAPID CABIN CLB; EARS POPPING; ETC.