Date: 201712
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Rain; Icing
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Situational Awareness; Communication Breakdown
Second reporter function: Pilot Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Gate; Flight Crew Rejected Takeoff
Contributing factors: Weather; Human Factors
Primary problem: Human Factors

Narrative: We had completed deice/anti-icing and began taxiing for departure. During this time we waited to configure the flaps for takeoff because we were in icing conditions with active precipitation. We planned to wait until we reached the hold short line to set the flaps for takeoff and complete the before takeoff checklist. We were anticipating a brief wait before departure for a wheels up time but upon approaching the end we were cleared for takeoff with traffic on approximately a six mile final. We then completed the before takeoff checklist. Next; we took the runway for a static takeoff. Earlier; we briefed [the takeoff]; flaps 18; static takeoff. When the first officer applied power for the takeoff and we just began the roll; I had remembered it was a flaps 18 takeoff and the flaps were set to 9. At this time I vocalized that the flaps were supposed to be 18 to the First Officer and he instinctively called for flaps 18. As a reaction to his callout; I set the flaps to 18 and immediately called 'Abort; Abort; Abort'. The First Officer then accomplished the rejected takeoff procedure. After safely exiting the runway we accomplished the after landing checklist; received an amended release from dispatch; and got deiced again before departing and completing the flight as originally planned.


Second narrative: While we were deicing/anti-icing we briefed we would place the flaps to 18 before the take-off checklist was run because we anti-iced in the flaps up position per the 'pre-deicing/anti-icing check' and did not want to have the unsprayed flaps down in the active precipitation in freezing conditions. We believed we would have several minutes at the end of the runway before our wheels up time would allow us to take off. Upon approaching the end of the runway tower cleared us for takeoff with traffic about 6 mile final. On the before takeoff check I read 'flaps 9'. Very shortly after beginning the take-off roll the captain said 'flaps should be at 18' and my knee jerk reaction was a call out for 'flaps 18'. Immediately I heard his 'abort; abort; abort' call out and I initiated the rejected take off. Everything was normal after rejecting the take-off. After exiting the runway and running the after landing checklist; we called dispatch for an amended release; returned for an additional de-ice/anti-ice; and performed all required checklists before departing again. Managing threats and errors is an integral part of completing a safe flight. Threats on this flight were the unusual take off configuration of flaps 18; my first time doing a very high trust setting for takeoff; deicing/anti-icing procedures; and a self induced perceived need to complete the before takeoff checklist before the traffic could land. I had briefed a flaps 18 departure; we discussed the profile before taxi; but when I read the data card under the self imposed pressure I had said 'flaps 9' which may have lead the captain into seeing flaps 9 matching my call out and not triggering in his brain the incorrect setting. When the captain said 'the flaps should be at 18' the first thought in my brain was 'flaps 18' which turned into my call out. This was incorrect and the correct response was to abort which we immediately accomplished once we both realized what we were doing. In the future; I will use this experience to remind myself 'slow down; breathe; nothing ever has to be rushed' we had adequate fuel and hold over time to wait for another wheels up time after the traffic landed.


Synopsis: ERJ-145 flight crew reported a rejected takeoff due to an incorrect flap setting.