Date: 201907
Local time of day: 0601-1200
Location: ZBW.ARTCC, NH
Flight conditions: VMC
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZBW
ATC / advisory: Center ZBW
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Confusion
Second reporter function: Pilot Not Flying; Captain
Anomaly: Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was PF [Pilot Flying] about to join the FLOSI3 STAR into EWR. I recall verifying the clearance to cross 30NM North of ALB at FL240. I recall checking the FMC as the CA [Captain] set the fix into the FMC for me and I recall pointing my finger at FL240 in the FMC. Passing through about FL255 on VNAV was when ATC told us about crossing traffic below and ahead. I saw this traffic on TCAS as -12 in white and around 10 o'clock position. I then commenced scanning the area where I thought the traffic would be. It was hazy so I never did see the traffic. Beyond that I saw no impending threat from the traffic. Then I heard the CA state he had control and there was the brief sound of the automation being turned off and the plane went into the climb up to around FL265 and I saw the airspeed decreasing. I wasn't sure what was going on because there was no sound of a TA/RA. For a brief moment I thought the CA saw something like dramatic like a near mid-air or extreme proximity to traffic. In reality that wasn't the case. Once I settled into the situation that was occurring around me; I queried the CA about what he was acting on. He expressed concern we had busted our altitude limit of FL260 and we had an impending conflict with the aircraft in TCAS. Then I called BOS Center to verify our last clearance to last clearance to cross 30N of ALB at F240. Boston Center confirmed that was still the case and then they asked us if we would still the make the clearance. We said unable and BOS Center said that okay. At this point the CA handed me over the aircraft as PF and to regain better SA I just went with FLCH [Flight Level Change] to do our best to try to go with the crossing restriction. After matters slowed down; the CA explained he acted in haste based on his concern the traffic was exceptionally close to us. This he pointed out was due to his ND [NAV Director] being on the expanded range and thus the target even though it never moved to TA status appeared artificially quite close. He also stated he intervened on taking over as PF because he started to doubt our clearance altitude thinking we had been cleared merely to FL260. We discussed the course of events that transpired and he apologized for taking over controls abruptly and he stated the events as he saw it. I kept flying the arrival to EWR. On the gate the three of us debriefed the event and lessons we took away from it.


Second narrative: I was Pilot Monitoring. We were filed and expected the FLOSI3 Arrival. We had been given initial clearance to cross HANAA at and maintain FL240. Boston Center then came back and changed clearance to descend and maintain FL260 but expect to cross HANAA at FL240. Shortly after cleared direct to ALB maintain FL260. Shortly after; then cleared to cross 30nm North of ALB at FL240. As monitoring pilot I set 24000 in window and it was verified by PF [Pilot Flying] and IRO. As we descended through FL260; BOS Center called out traffic at 10 O'clock and I heard 'he is at FL250 and you will pass overhead'. I immediately looked at NAV display and thought I was in lowest 10 mi setting. TCAS showed traffic at 10 O'clock and what I thought was about 4 miles and nearly co-altitude. I then immediately said I had the aircraft; disconnected A/P and stopped descent and actually climbed about 400' to FL264. FO [First Officer] then queried Center to verify descent to FL240. Center confirmed; we declared we wouldn't make 30nm north of ALB; but continued descent and reached FL240 as soon as possible. There was no conflict with traffic and flight continued without incident. The miscommunication was solely on my part as PM [Pilot Monitoring]. With all clearance changes and then momentarily confusing what I saw on NAV display; I reacted to what I deemed as a threat. After discussion after taking control of aircraft; both my FO and IRO confirmed they heard controller call out traffic as 'traffic 10 O'clock at FL250 and he will pass overhead'. I also misread my display. Traffic was actually about 15 no away not about 5 like I thought. I transferred control of aircraft back to FO and we put aircraft back on autopilot and continued descent. We landed normally and thoroughly debriefed flight to include full discussion of descent north of ALB.


Synopsis: Air Carrier flight crew reported miscommunication among themselves/ATC resulting in the Captain (PM) mistakenly taking control of the aircraft.