Date: 201701
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Takeoff / Launch
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Distraction
Second reporter function: First Officer; Pilot Flying
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Rejected Takeoff
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We departed the gate and were cleared to taxi. I called for the taxi check. I assumed my First Officer (FO) had started both engines since my attention and focus was outside taxiing the airplane. We did run the checklist; but I never focused on the engine instruments.As we approached the end of the runway we were cleared for takeoff; completed the before takeoff checklist and I aligned the airplane with the centerline and gave control to the FO. He advanced the thrust levers I'm guessing about 1/4 of the way towards the thrust set position when the nose immediately yawed to the right. He immediately retarded the thrust levers. We rolled less than 100 feet. Simultaneously we lost intercom between us. I took control of the airplane and told the tower we had a problem and needed to taxi clear. The tower cancelled our takeoff clearance; and we exited the runway. We sorted out our com problem; started the number 2 engine; re-ran the checklists and departed normally.I incorrectly assumed that the number 2 engine was running when I called for the taxi checklist.Add both engines running to the before takeoff checklist; as it is on the EMB 145. I now know why it's there.


Second narrative: Due to being near min takeoff fuel and a relatively low arrival fuel we agree to start engine 2 on the taxi. We ran the taxi checklist but I was focusing on the EICAS messages area instead of the engines.We approached [the runway] and were cleared for takeoff; the before takeoff checklist was completed; and the Captain (CA) aligned the aircraft. The CA gave me control of the aircraft and I began to move the thrust levers forward and called 'check thrust'. The aircraft began to yaw and I immediately retarded the thrust levers and eased the aircraft back to a full stop. At nearly the same time we lost intercom between us. The CA told the tower we had a problem and needed to taxi clear and took control. Tower cancelled our takeoff clearance; and we then exited on the taxiway. The Audio Control Panel (ACP) problem was fixed; started the number 2 engine; allowed for appropriate warm up; and re ran our checklists; and then departed normally.Neither myself nor the CA realized we forgot to start the number 2 engine. Task saturation. High workload. Demand for on time performance. Last leg of a 4 day trip. Relatively low arrival fuel dispatched and effort to save as much fuel as possible before Takeoff; for the flight.[Suggestions:] takeoff config button does not verify both engines are actually running. 'Engine number 2 start complete' on taxi checklist. SOP of starting both engines after pushback. Enough fuel on release that you really can start both engines at the gate.


Synopsis: EMB-175 flight crew reported that due to distractions and fatigue they began the takeoff roll with only one engine running.