Date: 201903
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B757 Undifferentiated or Other Model
Operator: Air Taxi
Operating under: Part 121
Flight plan: IFR
Flight phase: Takeoff / Launch
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Electrical Distribution Busbar
Component problem: Malfunctioning
Reporter organization: Air Taxi
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Aircraft; Human Factors
Primary problem: Ambiguous

Narrative: On rotation from Runway XXC at ZZZ; we experienced a RIGHT AC BUS EICAS; LEFT ENG EEC EICAS; RIGHT ENG EEC EICAS; CARGO DET AIR status message; and AFT EQT EXH FAN 1 status message. We accomplished the Right AC Bus checklist and restored power to the right AC bus; by resetting the right engine generator control and the right AC bus tie. Next; we accomplished the L/R ENG EEC QRH.The Captain had a conference call with Maintenance and Dispatch to deal with the two remaining status messages. Maintenance advised us that both cargo detector fans were inoperative in the cargo fire detection system; and possibly making the system inoperative. He was basing this on the MEL for CARGO DET AIR. As a result; with Maintenance's knowledge; the Captain elected to reset the circuit breaker S35 Fire Det Cargo Fan Control using his emergency authority. The cycled circuit breaker cleared the CARGO DET AIR status message. We continued to our planned destination.


Second narrative: During rotation on takeoff from ZZZ; EICAS displayed AC BUS OFF R; with all associated messages. Overhead panel confirmed R GEN CONT Switch (amber) 'OFF' light illuminated; R BUS (amber) 'BUS OFF' light illuminated; BUS TIE (amber) 'ISLN' light illuminated.Followed QRH checklist. R GEN on; R AC Bus re-powered; and Auto Bus tie re-established. Utility bus switches cycled restoring utility busses. All EICAS messages cleared; except: Advisory: R ENG EEC; L ENG EEC; Status: CARGO DET AIR and AFT EQ EXH FAN 1; Completed ENG EEC L (R).Next; competed VHF conference call with Dispatch and [Maintenance] to make sure we did not miss anything. All agree able to continue.Now; with time to investigate Status messages; decide to re-conference with [Maintenance]. There is no reference in the QRH to either status message. [Maintenance] comments that CARGO DET AIR means we have no cargo smoke detection. I elect to switch EICAS computer to R-L-Auto; no change. I elect to attempt the ECS-AUTO-ERASE procedure on the EICAS MAINT Panel; that clears the AFT EQ EXH FAN 1. I elect to cycle circuit breaker S-35; Fan Control circuit breaker; - status message cleared. All steps discussed with [Maintenance].Proceeded to destination; with EECs inoperative; uneventful.


Synopsis: B757 flight crew reported several aircraft system malfunctions associated with an electrical bus failure and the loss of cargo smoke detection.