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.
Synopsis
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.
Second reporter narrative
In cruise; in the clear; with distant thunderstorms and lightning; over the Amazon on a moonless night we lost the ISFD. The Captain SATCOM'ed dispatch and was connected to maintenance as well. We concurred that it was not prudent to continue the flight into our planned destination under those circumstances. I flew the airplane and coordinated with Center for a VFR diversion into an enroute airport. The First Officer was called back from his break and continued the flight and landing without further incidents. The QRH offered NO GUIDANCE for a loss of the ISFD instruments. The Dispatcher was very helpful throughout the entire process including coordinating gate and ramp service in at the foreign airport through another airlines and our own departure station personal. Maintenance asked the Captain if he was willing and comfortable in reseting the popped ISFD circuit breaker which we both refused as it is not a procedure we are allowed to perform. The ISFD was twice written in the logbook within the past 2 weeks. The first write up resulted in NO action required as it could not be duplicated once maintenance reseted the tripped CB; the other resulted in a battery pack change for the ISFD.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.