Date: 202106
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Dusk
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Second reporter function: Captain; Pilot Not Flying
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: The incident happened during our descent on the ZZZZZ arrival into ZZZ. As far as I remember; we had been cleared by the previous Controller and told to do the XXL transition. I had already programmed the FMS for that specific arrival and pre-loaded the ILS XXL. The weather was not an issue with a clear sky and great visibility. I briefed a visual approach for XXL; backed up with the routing of the ILS for that same runway; and made sure we had the discontinuity between the last point on the arrival - ZZZZZ1 and the first point on the approach - ZZZZZ1. We were then told to contact the next Controller and assigned different altitudes on the arrival while maintaining the routing. For some reason; at one point; I thought/assumed we were cleared for the visual and got rid of the discontinuity by linking the first point on the approach with the last point on the arrival - ZZZZZ1. I turned to the Captain to ask him to 'confirm' and proceeded by removing the discontinuity. Because we were not cleared for the approach yet; the aircraft proceeded past ZZZZZ1 on a XXX as expected; but because it was now programmed to fly the approach it started turning at ZZZZZ2. The Controller asked us if we were flying the RNAV; we responded that we were doing the XXL transition and as the Captain said these words we realized we had made a mistake by leaving the XXX. The Controller kindly reminded us what we were expected to do and gave us a heading to intercept the localizer for the visual XXL. What led to this mistake is mostly my fault. I was fixated on flying the visual; and I forgot to actually make sure we had been given the clearance before getting off the arrival. My mind was too focused on the preconceived idea of what was expected rather than what we had actually been cleared for that I failed to properly communicate with my Captain. I was complacent; and this led to confusion in the cockpit and with the Controller.


Second narrative: During our descent on ZZZZZ arrival into ZZZ; we were cleared to descend via ZZZZZ ; XXL transition. We programmed the FMS for that particular arrival and transition and preloaded the ILS XXL. The weather was good with clear sky and great visibility. Pilot Flying; briefed the visual approach XXL back it up by ILS. We made sure the discontinuity between the last point on the arrival ZZZZZ1 and the first point on the approach ZZZZZ1. We were told to contact the next Controller and assigned us different altitude on the arrival while maintaining the routing. I contacted the next Controller and for some reason we thought; we were cleared for visual via ZZZZZ1 transition. As we past ZZZZZ1; we continue to fly heading XXX as we approached ZZZZZ2 the plane was about to transition to the new fix. At this point ATC assigned us a heading 350 and asked us if we are flying the RNV transition? Which responded yes and I realized the error. At this point he assigned us 310 heading to intercept the localizer and cleared us for visual to XXL.We were both fixated and our mind was set on the preconceived idea of what was expected rather than what we had actually been cleared for; especially when the proceeding traffic receives that clearance. I (we) failed to confirm and communicate with each other and ATC. I got complacent and side tracked; the combination of these two led to the confusion in the cockpit and with the Controller.As a (Captain/Pilot Monitoring) I should have communicated and confirmed that we are both on the same page and understood the clearance and when in doubt ask the ATC for clarification. I want to make sure and get the confirmation before removing the discontinuity and not to rush. Do not assume if previous aircraft receives particular clearance we will get the same and avoid complacency. I will emphasize this on my future arrival briefings to ensure this doesn't happen again; FOOLISH ASSUMPTION/MISTAKE.


Synopsis: ERJ175 flight crew reported a clearance deviation due to flight crew communication breakdown during approach.