An air carrier flight crew has their B747-200 suddenly pitch up and roll to the right when the #1 IN...

Attributes
ACN	341442
Time
Date	199607
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ann
State Reference	AK
Altitude	msl bound lower : 31000 msl bound upper : 31800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : czvr
Operator	common carrier : air carrier
Make Model Name	B747-100
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 150 flight time total : 20000 flight time type : 5000
ASRS Report	341442
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : returned to intended course or assigned course
Consequence	other Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Level flight at FL310 on #1 autoplt coupled to #1 INS. Smooth WX. #1 INS sent a spurious signal to the autoplt causing the aircraft to pitch up violently, then roll to the right. Aircraft was recovered at FL318. 1 flight attendant was injured and a diversion was required for medical help. 90000 pounds of fuel was dumped. Vancouver ARTCC was advised of altitude excursion of 800 ft and the reason why. Callback conversation with reporter revealed the following information: the reporter was flying a B747-200 that was equipped with delco carousel INS units. The captain said that the #1 INS malfunctioned and caused the aircraft to pitch up violently and roll sharply to the right. The captain also said that when he looked at his instruments as an aid during the recovery he saw that they had failed. Also, the captain's ADI attitude indication showed a roll that was exactly opposite the actual roll position. The first officer's instruments were accurate and he made the recovery. The aircraft had climbed 800 ft, turned away from its course during the INS malfunction, but the return was quick and smooth according to the reporter and the deviation was not noted by the controller. A cabin attendant in the aft section of the main cabin was injured when she struck the ceiling and then part of the galley with her back. She has now recovered. There were no other injuries. The #1 INS showed 11 fault codes on the delco carousel INS after the event. The reporter said that he had had no feedback from maintenance technicians yet. He had talked to the flight department safety personnel and they were going to publish the results of their findings when the cause was found.

Original NASA ASRS Text

Title: AN ACR FLC HAS THEIR B747-200 SUDDENLY PITCH UP AND ROLL TO THE R WHEN THE #1 INS MALFUNCTIONS. 1 CABIN ATTENDANT WAS INJURED AND THE FLT WAS DIVERTED TO ANC FOR MEDICAL TREATMENT.

Narrative: LEVEL FLT AT FL310 ON #1 AUTOPLT COUPLED TO #1 INS. SMOOTH WX. #1 INS SENT A SPURIOUS SIGNAL TO THE AUTOPLT CAUSING THE ACFT TO PITCH UP VIOLENTLY, THEN ROLL TO THE R. ACFT WAS RECOVERED AT FL318. 1 FLT ATTENDANT WAS INJURED AND A DIVERSION WAS REQUIRED FOR MEDICAL HELP. 90000 LBS OF FUEL WAS DUMPED. VANCOUVER ARTCC WAS ADVISED OF ALT EXCURSION OF 800 FT AND THE REASON WHY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING A B747-200 THAT WAS EQUIPPED WITH DELCO CAROUSEL INS UNITS. THE CAPT SAID THAT THE #1 INS MALFUNCTIONED AND CAUSED THE ACFT TO PITCH UP VIOLENTLY AND ROLL SHARPLY TO THE R. THE CAPT ALSO SAID THAT WHEN HE LOOKED AT HIS INSTS AS AN AID DURING THE RECOVERY HE SAW THAT THEY HAD FAILED. ALSO, THE CAPT'S ADI ATTITUDE INDICATION SHOWED A ROLL THAT WAS EXACTLY OPPOSITE THE ACTUAL ROLL POS. THE FO'S INSTS WERE ACCURATE AND HE MADE THE RECOVERY. THE ACFT HAD CLBED 800 FT, TURNED AWAY FROM ITS COURSE DURING THE INS MALFUNCTION, BUT THE RETURN WAS QUICK AND SMOOTH ACCORDING TO THE RPTR AND THE DEV WAS NOT NOTED BY THE CTLR. A CABIN ATTENDANT IN THE AFT SECTION OF THE MAIN CABIN WAS INJURED WHEN SHE STRUCK THE CEILING AND THEN PART OF THE GALLEY WITH HER BACK. SHE HAS NOW RECOVERED. THERE WERE NO OTHER INJURIES. THE #1 INS SHOWED 11 FAULT CODES ON THE DELCO CAROUSEL INS AFTER THE EVENT. THE RPTR SAID THAT HE HAD HAD NO FEEDBACK FROM MAINT TECHNICIANS YET. HE HAD TALKED TO THE FLT DEPT SAFETY PERSONNEL AND THEY WERE GOING TO PUBLISH THE RESULTS OF THEIR FINDINGS WHEN THE CAUSE WAS FOUND.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

An air carrier flight crew has their B747-200 suddenly pitch up and roll to the right when the #1 INS malfunctions. 1 cabin attendant was injured and the flight was diverted to anc for medical treatment.