Narrative:

[We were] in cruise conditions at FL370; approximately 1 hour after takeoff; discovered integrated standby instrument system (isis) instrument blank with a displayed message on its face: 'do not use'. No other malfunctions present: electrical; adr's (air data reference) or pitot/static. Reset breakers all ok; no circuit breakers ECAM displayed open; no ECAM; memos or messages present. No abnormal guidance was available or known to us on the flight deck to rectify this in-flight loss of the isis. [We] could not find any applicable QRH procedure [and] could not locate in MEL for reference information either. The isis was positively operational climbing through FL180; because I observed both pilot not flying and pilot flying perform the 18;000 ft flow requiring setting standard. I feel the isis had just failed when we noticed it because all 3 flight crew members discovered it inoperative simultaneously. The captain established satcom voice with dispatch and maintenance. Maintenance was at a loss for cause and indicated no receipt of datalink messages regarding isis failure. There was little or no guidance from dispatch or maintenance on options for dealing with this situation pertaining to continuing operations; turn back and landing or ETOPS capability. The flight crew felt it was required equipment since it was not in the MEL and also most likely required in-flight for continuing operations and entering ETOPS/long range navigation conditions. Reluctant to continue long range operations with this degraded condition; we considered the prospects of a turn back/diversion and landing. This would most likely itself involve more than one hour of flight time and/or hours of fuel burn-off to maximum landing weight in this degraded condition. If we diverted/returned to field we wanted to have the isis back. If we continued; we had to have the isis back. Flight conditions were black night; on top; perhaps higher cirrus; no visible horizon. Due to our training; we considered an operable isis fundamental in the recovery of any potential unreliable airspeed abnormal. The only method maintenance was aware to regain the isis was by an electronic and equipment compartment (ee) circuit breaker (C/B) reset. We consulted and received dispatch and maintenance direction and authorization via satcom voice and ACARS to attempt a C/B reset in the ee compartment. 'Per mx okay to attempt reset panel H5 742VU D64 also K66 dispatch xa:59 end.' with the captain's permission; I as the relief pilot gained access to the ee area. The three approved C/B's were found in the 'in' position. Per maintenance direction I pulled all 3 C/B's and left them open for approximately 30 seconds. I then reset all 3 in the same order to the 'in' position. Upon returning to the flight deck; the isis was observed doing a self test; and then it regained full complete operation/display. We advised maintenance and dispatch and maintained our progress to the oceanic entry point. We monitored the isis; continued normal operation and felt it was now prudent to continue with no further problem. Maintenance and dispatch concurred. We experienced no further isis difficulty on the flight. An early alert 'info only item' describing the isis failure; C/B reset and recovery was entered in the logbook. Engineer meeting the flight was briefed by the captain regarding the write up.

Google
 

Original NASA ASRS Text

Title: An A330 ISIS displayed the message DO NOT USE with the attitude; airspeed; altitude; magnetic heading; and glide slope missing. The crew reset the applicable circuit breakers in the EE compartment to successfully restore the ISIS.

Narrative: [We were] in cruise conditions at FL370; approximately 1 hour after takeoff; discovered Integrated Standby Instrument System (ISIS) instrument blank with a displayed message on its face: 'DO NOT USE'. No other malfunctions present: electrical; ADR's (Air Data Reference) or pitot/static. Reset Breakers all OK; no Circuit Breakers ECAM displayed open; no ECAM; memos or messages present. No abnormal guidance was available or known to us on the flight deck to rectify this in-flight loss of the ISIS. [We] could not find any applicable QRH procedure [and] could not locate in MEL for reference information either. The ISIS was positively operational climbing through FL180; because I observed both pilot not flying and pilot flying perform the 18;000 FT flow requiring setting STD. I feel the ISIS had just failed when we noticed it because all 3 flight crew members discovered it inoperative simultaneously. The Captain established SATCOM voice with Dispatch and Maintenance. Maintenance was at a loss for cause and indicated no receipt of datalink messages regarding ISIS failure. There was little or no guidance from Dispatch or Maintenance on options for dealing with this situation pertaining to continuing operations; turn back and landing or ETOPS capability. The flight crew felt it was required equipment since it was not in the MEL and also most likely required in-flight for continuing operations and entering ETOPS/Long Range Navigation conditions. Reluctant to continue long range operations with this degraded condition; we considered the prospects of a turn back/diversion and landing. This would most likely itself involve more than one hour of flight time and/or hours of fuel burn-off to maximum landing weight in this degraded condition. If we diverted/returned to field we wanted to have the ISIS back. If we continued; we had to have the ISIS back. Flight conditions were black night; on top; perhaps higher cirrus; no visible horizon. Due to our training; we considered an operable ISIS fundamental in the recovery of any potential unreliable airspeed abnormal. The only method Maintenance was aware to regain the ISIS was by an Electronic and Equipment Compartment (EE) Circuit Breaker (C/B) reset. We consulted and received Dispatch and Maintenance direction and authorization via SATCOM voice and ACARS to attempt a C/B reset in the EE compartment. 'PER MX OKAY TO ATTEMPT RESET PANEL H5 742VU D64 ALSO K66 DISPATCH XA:59 END.' With the Captain's permission; I as the Relief Pilot gained access to the EE area. The three approved C/B's were found in the 'IN' position. Per Maintenance direction I pulled all 3 C/B's and left them open for approximately 30 seconds. I then reset all 3 in the same order to the 'IN' position. Upon returning to the flight deck; the ISIS was observed doing a self test; and then it regained full complete operation/display. We advised Maintenance and Dispatch and maintained our progress to the Oceanic Entry Point. We monitored the ISIS; continued normal operation and felt it was now prudent to continue with no further problem. Maintenance and Dispatch concurred. We experienced no further ISIS difficulty on the flight. An early alert 'Info only Item' describing the ISIS failure; C/B reset and recovery was entered in the logbook. Engineer meeting the flight was briefed by the Captain regarding the write up.

Data retrieved from NASA's ASRS site as of April 2012 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.