A B757 IN CRUISE DECLARED AN EMER AND DIVERTED DUE TO LOSS OF CABIN PRESSURE CAUSED BY A CABIN PRESSURE CTLR LOOSE IN THE EQUIP RACK.

Narrative

ACCOMPLISHED A PACKS OFF/BLEEDS OFF TKOF. DURING CLBOUT ATTEMPTED TO TURN ON THE L BLEED. L BLEED OFF LIGHT REMAINED ON AND WE HAD L ENG BLEED EICAS MESSAGE ACCOMPLISHED OPS MANUAL PROC AND STARTED APU TO RUN L AIR-CONDITIONING PACK IN CLB. PRESSURIZATION WAS NORMAL. A FEW MINS LATER AT ABOUT 17000 FT MSL WE GOT A L HI- STAGE LIGHT AND L HI-STAGE EICAS MESSAGE. ACCOMPLISHED OPS MANUAL PROC. L DUCT PRESSURE WAS LOW; BUT R DUCT PRESSURE AND SYS WAS NORMAL. PRESSURIZATION WAS NORMAL. LEVELED OFF AT FL290; CHKED PRESSURIZATION AND AIR- CONDITIONING; ALL NORMAL. WE WERE FLT PLANNED AT FL370. ELECTED TO CRUISE AT FL330 TO WATCH PRESSURIZATION. LEVELED AT FL330; ALL NORMAL. ABOUT 3-5 MINS AFTER LEVELOFF; CABIN ALT WARNING HORN SOUNDED AND CABIN ALT WARNING LIGHT ILLUMINATED. R DUCT PRESSURE AND AIR- CONDITIONING SYS WERE NORMAL; OUTFLOW VALVE WAS CLOSED; CABIN RATE OF CLB WAS 400-500 FPM. INITIATED EMER DSCNT; DECLARED AN EMER; ACCOMPLISHED EXPLOSIVE DECOMPRESSION/EMER DSCNT CHKLISTS. LEVELED OFF AT 14000 FT AND DIVERTED TO SLC. CABIN ALT AT 14000 FT STABILIZED AT 9500 FT BUT WOULD NOT GO LOWER. ENRTE TO SLC NOTICED L ENG N3 INDICATION WAS READING ZERO ON BOTH THE EICAS DISPLAY AND THE STANDBY ENG INDICATOR. ENG WAS OPERATING NORMALLY. LANDED AT SLC WITH CFR/EMER EQUIP STANDING BY. NO INJURIES TO PAX OR CREW. 1 FEMALE PAX TREATED FOR HYPERVENTILATION AND TRANSPORTED TO LCL HOSPITAL. NO ACFT DAMAGE. PRESSURIZATION HAD BEEN SELECTED TO AUTO #2. AT SLC MAINT; RAN A BITE CHK ON THE PRESSURIZATION SYS. THE #2 CTLR DISPLAYED FAULT PROBS. VISUAL INSPECTION FOUND THE CTLR LOOSE IN THE E&E RACK. IT HAD SLID FORWARD FROM NORMAL POS AND DISCONNECTED ITSELF. NO COCKPIT INDICATIONS OF CTLR MALFUNCTION OR SWITCH OVER WERE EVER DISPLAYED. BELIEVE LOSS OF PRESSURIZATION DUE TO MALFUNCTIONING/DISCONNECTED #2 PRESSURIZATION CTLR.