B747-200 PITCHES UP AND ROLLS R WITH LOSS OF INS. SUDDEN ROLL INJURES FLT ATTENDANT AND FLC DIVERTS INTO ANC.

Narrative

WE WERE IN CRUISE AT FL310 ON A FLT FROM SEATTLE TO HONG KONG WITH THE CAPT FLYING AND THE ACFT (B747-200) ON THE 'A' AUTOPLT AND PMS AND NAVING VIA 3 ABC INS UNITS (#1 INS TIED TO 'A' AUTOPLT) WHEN WE EXPERIENCED A COMPLETE LOSS OF THE #1 INS. THE LOSS WAS SUDDEN; IMMEDIATE AND COMPLETELY UNEXPECTED. THE LOSS OF THE INS CAUSED A VIOLENT UPSET OF THE 'A' AUTOPLT RESULTING IN A PITCH UP AND ROLL R. THE CAPT LOST HIS PRIMARY INSTS (HIS ATTITUDE GYRO WAS UPSIDE DOWN). HE TOOK CTL OF THE AIRPLANE IMMEDIATELY BUT WE HAD ALREADY CLBED TO FL318. THE CAPT PASSED CTL OF THE ACFT TO ME AND I THEN LEVELED IT BACK AT FL310 AND PUT THE ACFT ON THE 'B' AUTOPLT. A RPT WAS MADE TO VANCOUVER CTR CONCERNING THE LOSS OF THE INS AND THE RESULTING ALT TRANSGRESSION. AN UNFORTUNATE RESULT OF THE VIOLENT PITCH AND ROLL OF THE ACFT WAS AN INJURY SUSTAINED BY ONE OF OUR FLT ATTENDANTS WHO WAS THROWN BACKWARDS AGAINST THE CORNER OF A GALLEY WALL. SHE WAS IN SEVERE PAIN FROM THE BACK INJURY. AFTER AN EXAMINATION BY A DOCTOR AND AN EMT WHO WERE ONBOARD; THE DECISION WAS MADE TO DIVERT TO ANCHORAGE; SO SHE COULD BE REMOVED FROM THE FLT AND SENT TO A HOSPITAL. WE NOTIFIED VANCOUVER CTR OF THE DIVERSION; WERE CLRED DIRECT TO ANCHORAGE; DUMPED APPROX 90000 LBS OF FUEL; AND LANDED WITHOUT INCIDENT. THE #1 INS WAS REPLACED IN ANCHORAGE. WE SUBSEQUENTLY PROCEEDED TO HONG KING WITHOUT FURTHER INCIDENT.