Date: 201809
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: Marginal
Weather elements / visibility: Thunderstorm
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Tower ZZZ
Aircraft component: Gust Lock
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Distraction; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Human Factors

Narrative: While on the taxi up to runway XXR at ZZZ; I as the FO (First Officer) conducted the before takeoff briefing. We were waiting behind a number of jets and a single engine turbo prop and the briefing lead to a discussion about the approaching storm front in from the south and moving towards the end of the runway. Observing what the previous departing aircraft were doing and also observing a gust front our extended brief lead to a discussion of wind shear escape and what we as a crew would do to mitigate that threat. No other departing aircraft reported wind shear on their departure and we were then called to line up and wait. Subsequently we were given a heading and cleared for takeoff. As Pilot Flying (PF) I then went to set takeoff thrust and noticed that the gust lock was still engaged and both the captain and I immediately realized we hadn't completed the before takeoff checklist. We hadn't increased thrust or commenced the takeoff roll at all so the Captain requested a short delay on the threshold and we completed the flow and checklist. On completion of the before takeoff checklist we were given another vector and cleared for takeoff. We departed and the remainder of the flight was uneventful. Later; we decided it was worthwhile to complete the [safety report]; in order for the event to be properly analyzed by a third party. In our subsequent discussion we felt in mitigating the perceived threat of wind shear we became fixated which became the new threat and error of not ending the brief and moving onto the flow and before takeoff checklist. The result was the undesired aircraft state; lining up on the runway for takeoff with the gust lock still in and not properly configured for takeoff.Threat: fixation on other threats affecting the flightError: failed to complete before takeoff checklist[Result]: lining up on the runway incorrectly configuredIn this specific case; [I would suggest making] a clear ending of the before takeoff brief which would lead into the before takeoff checklist.Fixation; avoid fixation on tasks or conversations as it can lead to non-identification of other threats or tasks.




Synopsis: ERJ-145 First Officer reported the before takeoff checklist was not completed prior to taxi into position for takeoff.