Narrative:

Climbing out we experienced a fwd equipment ovht EICAS message. I instructed international relief officer to be ready with QRH after we finished after takeoff clean up duties. First officer was PF and international relief officer and I worked the QRH to fix the issue; which resulted in us having to go to stby position on equipment cooling. Then a few minutes later the EICAS message returned and we ran the QRH again (please leave the hard copy qrhs in the cockpits; far superior product to use when things are getting busy!). This resulted in us going to ovrd on the equipment cooling selector.we continued our route of flight; and I began to think through the possible implications of operating in ovrd; using pressure differential to keep my displays and navigation and communication 'alive'; should we lose cabin pressure over a hostile environment; such as the oceanic airspace at night; with no airport within a couple of hours around our mid-point. My ETOPS flights are planned with a fuel contingency to ensure I can make it to a suitable ETOPS alternate in the event of both an engine failure and depressurization; so we are always prepared and equipped to handle that worst case scenario. But what if I have lost my cockpit displays - EFIS (electronic flight instrument system)/CDU etc? I might not be able to communicate and navigate the plane to an airport for a safe landing. I also lost all satcom communication facilities during this event by the way. VHF ACARS datalink continued to work for my immediate purposes; but I would lose that over the ocean. I instructed dispatch to contact me through arinc for a phone patch with maintenance control to determine best course of action.maintenance control did not seem to appreciate how easy it might be to end up with a loss of cabin pressure; saying I would need 'multiple system failures' to end up depressurized. I pointed out that I only needed an uncontained engine failure to end up depressurized and how long would I have my suite of flight; navigation and communication instruments and tools at my disposal. Maintenance control said I would have these for at least 90 minutes after loss of pressure; but the non-normals; fwd eqpt cooling checklist; suggests that any avionics; and electronics; to include displays; not powered by the standby busses; are subject to imminent failure - my capitalized emphasis. If that were indeed to happen; the aircraft and all aboard could quickly be in peril. Clearly we were not having a meeting of the minds. After further discussion; I indicated that in my opinion we were not going to be able to safely continue the flight and that I intended to divert to a safe landing while still able; prior to oceanic airspace entry and the potential threats associated with it. Dispatch instructed me to take the aircraft to an enroute airport where maintenance could assist. (There is a history of equipment cooling problems with this particular aircraft by the way) ATC facilitated our routing to an enroute alternate but we experienced extensive vectoring delays at low level going into the divert airport. The cloud base was lowering; and then at about 1.0 pressure diff; we experienced (and had expected at some point) a total loss of equipment cooling. I then elected to use my captain's emergency authority to return the eqpt cooling switch to the norm position; which recovered some cooling. We were able to complete the ILS to a normal landing at the divert airport. The aircraft was worked on by maintenance and we took off for our filed destination; having waived the far 117 by the allowable 2 hours. No further issues were noted on the flight. Kudos to the divert airport's maintenance for their diligence in fixing the aircraft.

Related reports:

Google
 

Original NASA ASRS Text

Title: B767 Captain reported after takeoff an EICAS alerted FWD EQUIP OVHT. The QRH was completed which extinguished the alert. A short time later the EICAS alerted again so the Captain diverted to a nearby airport rather than enter oceanic airspace at night.

Narrative: Climbing out we experienced a FWD EQUIP OVHT EICAS message. I instructed IRO to be ready with QRH after we finished after takeoff clean up duties. FO was PF and IRO and I worked the QRH to fix the issue; which resulted in us having to go to STBY position on equipment cooling. Then a few minutes later the EICAS message returned and we ran the QRH again (please leave the hard copy QRHs in the cockpits; far superior product to use when things are getting busy!). This resulted in us going to OVRD on the equipment cooling selector.We continued our route of flight; and I began to think through the possible implications of operating in OVRD; using pressure differential to keep my displays and navigation and communication 'alive'; should we lose cabin pressure over a hostile environment; such as the oceanic airspace at night; with no airport within a couple of hours around our mid-point. My ETOPS flights are planned with a fuel contingency to ensure I can make it to a suitable ETOPS alternate in the event of both an engine failure and depressurization; so we are always prepared and equipped to handle that worst case scenario. But what if I have lost my cockpit displays - EFIS (Electronic Flight Instrument System)/CDU etc? I might not be able to communicate and navigate the plane to an airport for a safe landing. I also lost all SATCOM communication facilities during this event by the way. VHF ACARS datalink continued to work for my immediate purposes; but I would lose that over the ocean. I instructed Dispatch to contact me through ARINC for a phone patch with Maintenance Control to determine best course of action.Maintenance Control did not seem to appreciate how easy it might be to end up with a loss of cabin pressure; saying I would need 'multiple system failures' to end up depressurized. I pointed out that I only needed an uncontained engine failure to end up depressurized and how long would I have my suite of flight; navigation and communication instruments and tools at my disposal. Maintenance Control said I would have these for at least 90 minutes after loss of pressure; but the non-normals; FWD EQPT COOLING checklist; suggests that any avionics; and electronics; to include displays; not powered by the standby busses; ARE SUBJECT TO IMMINENT FAILURE - my capitalized emphasis. If that were indeed to happen; the aircraft and all aboard could quickly be in peril. Clearly we were not having a meeting of the minds. After further discussion; I indicated that in my opinion we were not going to be able to safely continue the flight and that I intended to divert to a safe landing while still able; prior to oceanic airspace entry and the potential threats associated with it. Dispatch instructed me to take the aircraft to an enroute airport where maintenance could assist. (There is a history of equipment cooling problems with this particular aircraft by the way) ATC facilitated our routing to an enroute alternate but we experienced extensive vectoring delays at low level going into the divert airport. The cloud base was lowering; and then at about 1.0 pressure diff; we experienced (and had expected at some point) a total loss of equipment cooling. I then elected to use my Captain's Emergency Authority to return the EQPT COOLING switch to the NORM position; which recovered some cooling. We were able to complete the ILS to a normal landing at the divert airport. The aircraft was worked on by maintenance and we took off for our filed destination; having waived the FAR 117 by the allowable 2 hours. No further issues were noted on the flight. Kudos to the divert airport's maintenance for their diligence in fixing the aircraft.

Data retrieved from NASA's ASRS site 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.