AN ACR DC9 FLC; THE R GENERATOR FAILS WITH AN AC LOCKOUT AND AN AUTO PRESSURIZATION FAILURE. THEY MAKE AN AUTH EMER DSCNT WITHOUT INJURY OR MASK DEPLOYMENT AND RETURN TO THEIR DEP ARPT.

Narrative

SHORTLY AFTER REACHING FL290; THE R GENERATOR AND AC XTIE LOCKOUT LIGHT ILLUMINATED. THE AUTOPLT DISENGAGED AND THE AUTO PRESSURIZATION FAILED. ATTEMPTS TO CTL THE CABIN WERE UNSUCCESSFUL. ATC WAS ADVISED; AN EMER WAS DECLARED; AND AN EMER DSCNT WAS BEGUN. THE MOST IMPORTANT PRIORITY WAS THE UNSATISFACTORY PRESSURIZATION AND PAX SAFETY. DURING THE EMER DSCNT THE R ENG OIL QUANTITY AND PRESSURE INDICATED ZERO. THE R ENG WAS SECURED AND THE CHKLISTS WERE COMPLETED. IT WAS DETERMINED THAT THE R OIL PRESSURE AND QUANTITY WERE IN FACT OPERATING NORMALLY; THEREFORE; THE R ENG WAS RESTARTED. A ROUTINE APCH AND LNDG AT PIT FOLLOWED. UPON ARR AT THE GATE A LOG ENTRY WAS MADE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR IS A FO ON AN ACR DC9-30. HE SAID THAT THE ONSET OF THE PROB WAS SUDDEN. THE GENERATOR JUMPED OFF THE LINE AND WHEN THE FLC CHKED THE CAUTION LIGHTS THEY NOTED THAT IN ADDITION TO THE NORMAL GENERATOR AND BUS OFF LIGHTS THE AC XTIE LIGHT WAS ALSO ILLUMINATED INDICATING THAT NO OTHER SOURCE WOULD BE ACCEPTED FOR THE R BUS. HE SAID THAT AS THEY WERE GOING THROUGH THEIR ABNORMAL CHKLISTS THEY REALIZED THAT THE CABIN ALT WAS INCREASING. HE SAID THAT HE WAS UNABLE TO USE THE AUTO CTL FUNCTION OF THE PRESSURIZATION SYS AND THE ALTERNATE AND STANDBY SYS COULD NOT STOP THE RISING CABIN ALT. THE FLC DECLARED AN EMER AND WERE CLRED DOWN BY THE ARTCC CTLR. THE DSCNT WAS MADE TO BELOW 10000 FT BEFORE THE MASKS DROPPED. THEY RETURNED TO PIT. THE RPTR SAID THAT HE HAS NOT LEARNED OF THE CAUSE OF THE ELECTRICAL PROBS; BUT THE ACFT WAS REPAIRED AND FLYING THE NEXT DAY.