Date: 202009
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B787 Dreamliner Undifferentiated or Other Model
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: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Communication Breakdown; Training / Qualification; Confusion
Second reporter function: Relief Pilot; First Officer
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Flight Crew
When detected: Other Takeoff Roll
Result: Flight Crew Returned To Gate; Flight Crew Rejected Takeoff; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: All pilot crew members were present at scheduled report time; and pre-flight planning was accomplished as a crew. We arrived at the aircraft together approximately one hour before scheduled push time. Flight deck preparation duties were accomplished uneventfully in accordance with SOP. During flight deck preparation; I was designated by the Captain as the Pilot Monitoring for the first leg. The Captain accomplished the departure briefing; and I do not recall any deviations from the standard briefing. We pushed one minute early and proceeded uneventfully to Runway XXC. There were no aircraft anomalies during start and taxi. When cleared by ATC and after accomplishing runway verification; we initiated the takeoff roll. Another heavy aircraft had just departed on the same runway. The Captain made the 'check thrust' callout; and I replied with the 'thrust set' callout. After verifying all three airspeed indicators were matched and increasing; I focused my attention on the engine instruments while periodically cross-checking the airspeed indicator. All aircraft systems appeared to be performing normally; and I noticed normal aircraft acceleration. I glanced down the runway once prior to making the '100 knots' callout to verify that we were tracking centerline; then remained inside the cockpit until the Captain initiated the reject. I don't recall any significant yaw during the takeoff roll other than normal motion associated with the tracking of runway centerline. Approaching V1 (Takeoff Decision Speed); the Captain pulled the throttles to idle; initiating a rejected takeoff. I was surprised by this action; as I had not sensed a condition requiring a rejected takeoff. I did not hear a 'reject' callout. I noticed the speedbrake handle deploy and felt the RTO (Rejected Takeoff) brakes engage; but I do not remember looking to verify that the thrust reversers were in reverse. I heard the 'V1' callout shortly after the reject was initiated. I did not make the '80 knots' callout. When we were almost stopped; I made a 'remain seated; remain seated' PA announcement. I reported to ATC that we had rejected on runway XXC and that we were stopped on the runway between the five and six boards. I was confused about why the Captain had rejected the takeoff. I assumed he had seen something that I hadn't; and I was searching the instrument panel for the reason. The Captain said he felt a pronounced right swerve that felt like an engine failure; which prompted him to reject the takeoff. The IRO suggested looking at the wheels synoptic to check for a blown tire; but there was no indication of one. At the IRO's recommendation; we completed the rejected takeoff non-normal checklist. We did not request emergency vehicle response. We taxied clear of the runway and held position for a few minutes with the parking brake released while monitoring brake temperatures. I recall the hottest brake being number 7 with a value of 7.7. With brake temperatures no longer increasing; we elected to taxi to the gate; and coordinated with ATC; Operations and [Maintenance Control] for a gate return. We accomplished the BRAKE TEMP non-normal during the taxi back to the gate. Upon blocking in; we debriefed Maintenance in the cockpit and then departed the aircraft with the parking brake released after accomplishing all post-flight duties and a flight crew debrief. I spoke with [Operations] and completed a human factors questionnaire with her. While accomplishing flight deck preparation after plane swap and re-release; I was released from the trip.I recall V1 being 137 knots. I estimate the reject was initiated at approximately 130 knots; because I heard the automated 'V1' callout occur just after the reject was initiated. The 'V1' callout definitely occurred after the reject was initiated; because I remember being confused by sensing the deceleration at the same time as hearing the 'V1' callout. I suspect there was some residual acceleration after the throttles were pulled to idle which triggered the 'V1' callout; but by the time I heard the callout we were already decelerating.


Second narrative: I was in the Jumpseat. It was the Captains takeoff runway XXC. At 120 to 130 knots; the Captain rejected the takeoff without announcing the Reject.The airplane came to a complete stop on the runway. A few seconds passed; I said; who's gonna say remain seated? The FO (First Officer) said; I will; and made the remain seated call over the PA.I said; we need to tell ATC we rejected. The FO then let ATC know.I realize that the ATC call comes before the remain seated call. My biggest concern at that moment was the possibility of an un-commanded passenger evacuation. And since no one in the cockpit was saying or doing anything yet; I strongly suggested that someone say; REMAIN SEATED.A few seconds went by. I said; should we do the Rejected takeoff checklist? The CA (Captain) agreed and called for it.The FO began to read the checklist; then the Cabin call message displayed. I asked the Captain; do you want me to get that? He said yes.The FA (Flight Attendant) on the phone asked if things were ok; then asked if we were going to make an announcement. I asked the Captain if he wanted to make a PA; he directed me to make an announcement. I said; ladies and gentlemen; we have rejected the takeoff due to an abnormality; we are running a checklist; please remain seated with your seatbelts fastened and follow your flight attendants instructions. As I finished the announcement; the FO was on step 5 of the rejected takeoff checklist.The CA announced that he wanted to taxi clear of the runway and he released the brakes. I said; should we make sure that the tires are ok first? The FO selected the gear synoptic page. All tire pressures were normal; but brake temperatures were 3.5 and rising. The FO then continued with the Rejected takeoff Checklist.I began to smell hot brakes in the cockpit; a hot rubber smell. Just then the cabin call light illuminated; I answered and the FA said that there was a hot rubber smell near door 3. I told her it was the brakes and that we would make an announcement. The Captain then directed me to make another announcement.I said; ladies and gentleman; what you are smelling is the elevated temperature of the brakes; the indications are within limits; please remain seated and follow the flight attendants instructions while we finish our checklists. The FO asked if we should call the fire trucks. The Captain said no I think we're ok.Tower then asked us what the reason was for the rejected takeoff. The Captain told the FO that the airplane had an un-commanded yaw to the right. The FO relayed that information to Tower.As we taxied clear of the runway the Captain said that he felt a yaw and thought that an engine had failed; that's why he rejected.The Captain said let's go back to the gate; and directed the FO to call [Operations]. I interjected and said do you think we should call maintenance first? He said yes.I called maintenance; explained the situation; I gave them the brake temps and asked their opinion on returning to the gate. Local maintenance said it would be fine to go to the gate. In hind sight; I should have called [Maintenance Control]; but at the time it was more efficient to call local maintenance on the radio.As we taxied to the gate I asked the Captain not to pull into the gate until I reviewed the rejected takeoff; and performance sections of the FM (Flight Manual). Even though I just asked maintenance; I wanted to be sure there were no restrictions on bringing an airplane with hot brakes to the gate.I pulled up and reviewed [the FM sections] with the CA and FO. A BRAKE TEMP advisory message was now displayed.We parked the airplane at the gate and maintenance came to the cockpit. One of the mechanics had a laptop. He asked the Captain what happened and typed the Captains response into his laptop. The Captain said he felt a severe yaw to the right; he thought it was an engine failure and he rejected the takeoff. [Maintenance] asked the FO if he felt the yaw; the FO said; not really. [Maintenance] asked me if I felt the yaw; I told him that I felt a yaw to the left after the CA began the rejected takeoff maneuver.[Maintenance] then said that he downloaded the data from the airplane and that no anomalies were found. The Captain said then maybe it was a gust of wind that yawed the airplane to the right. I told [Maintenance] that the Quick Turnaround Landing Weight Limit was not exceeded and I referenced the FM performance section with him. In hind sight; I should have advised the CA and FO to include the information outlined in FO in their rejected takeoff maintenance write up.The mechanics left; the Captain then debriefed. He said that he felt a significant yaw to the right; he said that he did not announce 'REJECT' and that he should have. He thanked us for backing him up.We went to the new airplane. I did the exterior preflight. I got a call from the [Flight Ops Manager] who asked me a list of HF (Human Factors) questions to gauge my stress level. I answered her questions.15 minutes later the Captain's phone rang; it was the chief pilot who advised us that a safety investigation is underway on the event and that we were being pulled off line with pay.


Synopsis: B787 flight crew reported high speed RTO.