Date: 201512
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: B757-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Aircraft component: AC Generation
Component problem: Failed; Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Confusion
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Rejected Takeoff; Flight Crew Returned To Gate; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During the takeoff roll; after calling 'Standard Power set' and before the '80 Knots call' our aircraft experienced a sudden and simultaneous complete electrical failure except for the emergency/standby battery bus. All we heard in the cockpit was a 'clunk' followed by complete dark cockpit except for the standby ADI and left radio and one IRU. The Pilot Flying immediately performed a Rejected Takeoff (RTO) as I called the problems. Using the remaining radio I called tower and informed them we were aborting and asked if they could see us. They informed us we were completely 'dark'. As we came to a stop on the runway the Captain and I analyzed the situation and determined we should start the APU to get some taxi lights and outside visibility for safety. We accomplished this; got the utility bus back on line; and with the towers permission taxied back to the ramp area.This event was caused by the simultaneous coming off line by both generators leaving battery power only. I have heard that there was a catastrophic failure of one Integrated Drive Generator (IDG) which caused a surge knocking the other generator off line.Speaking to our fleet experts after the event I was informed that what we experienced was 'impossible' but yet it happened. If it had happened 10 seconds later we would have been airborne with no checklist procedures to follow. Prior to turning the APU on we confirmed we had no indication of fire with the tower and could not smell any smoke/fumes. However the maintenance personnel said there was indication of 'burning' electrical parts. Again; our experts have told us the chances of having a simultaneous dual gen failure with no warnings is 'impossible' but I would think exploring the art of the possible is perhaps needed.

Callback: The First Officer expressed his concerns about the lack of a checklist procedure for a dual generator failure and the response that 'it can't happen.'

Second narrative: During the Takeoff roll on above 40 KIAS and below 80 KIAS we lost all electrical power simultaneously except for battery power. We were able to exit the runway safely after the Rejected Takeoff (RTO). We started the APU and performed the applicable QRH procedures to include referencing the Brake Cooling Chart.


Synopsis: A B757 flight crew experienced a dual generator failure during the takeoff roll and rejected the takeoff.