B757 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Troubleshooting; Distraction
Aircraft Equipment Problem Less Severe
Flight Crew FLC complied w / Automation / Advisory
Aircraft
While at cruise altitude (FL380) midway through flight; R IRS DC FAIL EICAS displayed along with DC FAIL light for approximately 10-20 seconds then extinguished. QRH checklist completed and we decided to continue to [our destination]. Around the same time; we began hearing a clicking sound coming from the area right of the First Officer's seat near the right Circuit Breaker (CB) panel; printer and AC power outlet. All CBs checked in and clicking stopped for a while. Approximately 10 to 15 minutes later; the clicking sound returned. This stopped after a few minutes and at this point we were near our top of descent. Shortly thereafter; we lost the Captain's displays; FMC and the top EICAS display; as well as losing all autopilots and auto throttles. EICAS messages were plentiful...upwards of 30. Captain asked for lower altitude below RVSM airspace and asked for clearance direct to [destination] while breaking out the QRH. First Officer flew the airplane. Captain determined that the L AC BUS OFF EICAS message was the source of our problems. He then ran the QRH checklist for L AC BUS OFF. L AC BUS would not reset. Captain selected Right Instrument Source Select Panel to receive displays and managed flight from right FMS. We initially were on vectors to intercept ILS; but due to Flap indicator being inoperative; we chose to back up flap operation with ALTN flaps. Requested delay vectors to configure properly and discuss flap indications. We decided to use flaps 20 for approach and use [a different runway] for longer landing rollout. In addition; received EQPT OVHT message and Captain ran appropriate checklist. Approach and landing conducted uneventfully. Maintenance debriefed and AML entry input by Captain. Duty officer called and debriefed by Captain.
[Report narrative contained no additional information.]
B757 flight crew reported experiencing an electrical issue resulting in several system rendered inoperative or degraded. Flight landed normally.