A B767-400 in cruise FL330 experienced loss of captain's, first officer's and center electronic navi...

Attributes
ACN	495539
Time
Date	200012
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : phx.airport
State Reference	AZ
Altitude	msl single value : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zab.artcc
Operator	common carrier : air carrier
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute airway : j10.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	495539
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : flt instrument blank other flight crewa other flight crewb
Resolutory Action	aircraft : equipment problem dissipated flight crew : overcame equipment problem
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Company Chart Or Publication Aircraft
Primary Problem	Aircraft

Narrative:

During cruise flight, experienced failure of 4 out of 6 instrument display screens. All 4 inboard screens failed simultaneously including upper and lower EICAS displays and captain and first officer navigation displays. An electronic flight crew bulletin had been issued on the day before which was viewed and a copy printed and retained by crew. This bulletin was issued as a result of incidents experienced at another carrier on this type aircraft. It contained procedures and guidance to correct the problem. Company flight control and maintenance was contacted and in concert guidelines followed to restore displays. Procedures involved removing power to one 'display processing computer' at a time by pulling the appropriate circuit breaker. There are 3 display processing computers: left, center, right. Unpwring the right display processing computer first was no help, therefore, repwred. Upon repwring the center display processing computer, all 4 inoperative displays were restored. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a B768-400 which had the electronic instruments for navigation and engine displays that conform to the B777. The reporter said after the incident a conference call was made to boeing, electronic instrument manufacturers and the carrier's engineering department where it was revealed the problem was a software fault in the display processing computer's fault mode.

Original NASA ASRS Text

Title: A B767-400 IN CRUISE FL330 EXPERIENCED LOSS OF CAPT'S, FO'S AND CTR ELECTRONIC NAV AND ENG INST DISPLAYS DUE TO A KNOWN SOFTWARE FAULT.

Narrative: DURING CRUISE FLT, EXPERIENCED FAILURE OF 4 OUT OF 6 INST DISPLAY SCREENS. ALL 4 INBOARD SCREENS FAILED SIMULTANEOUSLY INCLUDING UPPER AND LOWER EICAS DISPLAYS AND CAPT AND FO NAV DISPLAYS. AN ELECTRONIC FLC BULLETIN HAD BEEN ISSUED ON THE DAY BEFORE WHICH WAS VIEWED AND A COPY PRINTED AND RETAINED BY CREW. THIS BULLETIN WAS ISSUED AS A RESULT OF INCIDENTS EXPERIENCED AT ANOTHER CARRIER ON THIS TYPE ACFT. IT CONTAINED PROCS AND GUIDANCE TO CORRECT THE PROB. COMPANY FLT CTL AND MAINT WAS CONTACTED AND IN CONCERT GUIDELINES FOLLOWED TO RESTORE DISPLAYS. PROCS INVOLVED REMOVING PWR TO ONE 'DISPLAY PROCESSING COMPUTER' AT A TIME BY PULLING THE APPROPRIATE CIRCUIT BREAKER. THERE ARE 3 DISPLAY PROCESSING COMPUTERS: L, CTR, R. UNPWRING THE R DISPLAY PROCESSING COMPUTER FIRST WAS NO HELP, THEREFORE, REPWRED. UPON REPWRING THE CTR DISPLAY PROCESSING COMPUTER, ALL 4 INOP DISPLAYS WERE RESTORED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A B768-400 WHICH HAD THE ELECTRONIC INSTS FOR NAV AND ENG DISPLAYS THAT CONFORM TO THE B777. THE RPTR SAID AFTER THE INCIDENT A CONFERENCE CALL WAS MADE TO BOEING, ELECTRONIC INST MANUFACTURERS AND THE CARRIER'S ENGINEERING DEPT WHERE IT WAS REVEALED THE PROB WAS A SOFTWARE FAULT IN THE DISPLAY PROCESSING COMPUTER'S FAULT MODE.

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.

A B767-400 in cruise FL330 experienced loss of captain's, first officer's and center electronic navigation and engine instrument displays due to a known software fault.