Narrative:

During cruise the ifsd completely failed and its circuit breaker tripped. We referred to the QRH and found no guidance there for this failure. As we were in VMC at the time; the relief first officer and I agreed that landing enroute in VFR conditions would be the safer alternative to continuing on night IMC with no standby instruments available. The relief first officer - who was the pilot flying -coordinated with center for a turn toward an enroute foreign destination while I called dispatch via satcom. The dispatcher agreed with our assessment providing coordination for the diversion and also put me in touch with maintenance control. I was surprised when they asked if I was comfortable with resetting the tripped circuit breaker; which I was not. Even if the ifsd had started working; I would have had no idea of the condition of the internal battery. It should be noted that there were two prior write-ups on the ifsd; one in which nothing was done and the other where the battery pack was changed. We landed at the foreign airport in visual conditions with no further problems; and a mechanic flew in to replace the ifsd. After landing I checked the MEL and found that dispatch without ifsd is limited to day VMC only.

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Original NASA ASRS Text

Title: B767 experienced a standby instrument failure (IFSD) in cruise during international flight and elected to divert to a foreign airport for maintenance. Aircraft had a history of standby instrument (IFSD) failures.

Narrative: During cruise the IFSD completely failed and its circuit breaker tripped. We referred to the QRH and found no guidance there for this failure. As we were in VMC at the time; the Relief First Officer and I agreed that landing enroute in VFR conditions would be the safer alternative to continuing on night IMC with no standby instruments available. The Relief First Officer - who was the pilot flying -coordinated with Center for a turn toward an enroute foreign destination while I called dispatch via SATCOM. The Dispatcher agreed with our assessment providing coordination for the diversion and also put me in touch with Maintenance Control. I was surprised when they asked if I was comfortable with resetting the tripped circuit breaker; which I was NOT. Even if the IFSD had started working; I would have had no idea of the condition of the internal battery. It should be noted that there were two prior write-ups on the IFSD; one in which nothing was done and the other where the battery pack was changed. We landed at the foreign airport in visual conditions with no further problems; and a mechanic flew in to replace the IFSD. After landing I checked the MEL and found that dispatch without IFSD is limited to Day VMC only.

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.