EMB-170 flight crew reported an electrical system failure in cruise affecting multiple aircraft systems. Flight crew diverted and landed safely.
Synopsis
EMB-170 flight crew reported an electrical system failure in cruise affecting multiple aircraft systems. Flight crew diverted and landed safely.
Narrative
First officer was PF and after reaching cruise altitude FL350 for approximately 15 minutes; we had multiple IECAS messages including A-I ENG 1 FAIL; AC BUS 1 OFF; DC BUS 1 OFF; ICE DETECTOR 1 FAIL; IDG 1 OFF BUS; VHF 3 FAIL; ADS 1 FAIL; AVNX MAU 1B FAIL; AP FAIL; SPOILER FAULT; EMER LT ON; SLAT LO RATE; TAT 1 FAIL; CCD 2 FAULT. Additionally the following items were effected: ADS3 Reversion; EFIS SCREEN DU 1 and 4 fail; Autopilot fail; auto-throttle fail; MCDU 1 fail; CCD 2 fail; A-I MODE NOT AUTO. We had approximately 18 irregular conditions. After assessing that our remaining reliable flight instruments including the IESS were on my (Captain) side; I announced my flight controls and took the flight controls. As I continued to hand fly the aircraft the FO initiated QRH procedures for AC BUS 1 OFF; DC BUS 1 OFF. After that we told ZZZ center that we had an electrical failure and we were [requesting priority handling]. It appeared that we were experiencing conditions similar to an electrical emergency; but IDG 2 was working; the RAT had not deployed; and DU panel 5 was working. Wanting to start the APU; we requested FL 300. Reaching FL 300 we successfully started the APU; and continued to asses our multiple irregular conditions. We were unable to view the electrical synoptic page. The FO also completed QRH procedure for AVNX MAU 1B FAIL. Assessment included that with IDG 2 operating; normal electrical transfer of power to restore AC BUS 1 and DC BUS 1 should have occurred but this had not happened. This lead me to believe there was a fault in system 1. We notified the flight attendants and passengers that because of an electrical problem; we would likely be diverting to an alternate airport. The QRH warned us that flight in icing conditions required selecting ice protection mode selector to on which we did; and this also made staying clear of icing conditions or remaining in VMC a priority as we determined a suitable diversion airport. Most airports behind us had been experiencing IFR; rain and freezing rain. ATC assisted in finding a diversion airport. Initially ATC said that ZZZ was VFR so we requested diversion to ZZZ. We communicated to the FA's and Passengers that due to an electrical issue; we would be diverting to ZZZ but then several minutes later ATC said ZZZ was marginal and reporting icing conditions. We asked about ZZZ1 and ATC said ZZZ1 was VFR and negative icing reports. We confirmed with ATC that we were [requesting priority handling] and requested CFR (crash fire rescue) for ZZZ1. We were cleared direct to ZZZ1 which the FO loaded into his and the only operable MCDU. The FO did all communications with #2 MCDU including trying to ACARS dispatch but that was inoperative. I concentrated on hand flying the aircraft in IMC conditions the entire descent. Finding a nearest suitable alternate was difficult since neither Nav Display worked and #1 MCDU was inoperative; so I used my tablet map for situational awareness. Via the intercom I told the FA's that because of poor weather in ZZZ we would now be diverting to ZZZ1; landing in 20 minutes; they did not need to brace. I also made another announcement to the passengers that due to poor weather in ZZZ we would now be landing in ZZZ1 and please pay attention to the FA's as they prepare the cabin for landing. An attempt was made to communicate to dispatch through different means but that was unsuccessful. We advised ATC to communicate to dispatch of our situation and diversion to ZZZ1. 10 minutes prior to landing we notified the FA's that we would be landing in 10 minutes. We completed our primary QRH procedures setting up for full flap landing on runway XX at ZZZ1. After an uneventful landing we stopped on the runway and confirmed that we could safely taxi clear of the runway. After stopping on the taxiway we confirmed that we could safely taxi to the gate. We taxied to gate and deplaned our passengers. CFR confirmed that everything was OK. I contacted dispatch; Maintenance control; and Chief Pilot. I also wanted to take a moment to mention what a great job my supporting crewmembers did. First Officer is still a low time First Officer; but he did an extraordinary job in this [priority] situation. Flight attendants; with their many; many years of experience helped keep the passengers safe and calm in the [priority handling] diversion.
Second reporter narrative
[Report narrative contained no additional information]
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.