Date: 201901
Local time of day: 0601-1200
Location: ZZZZ.ARTCC, FO
Flight conditions: VMC
Aircraft: B787-900
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: Center ZZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Workload
Second reporter function: Relief Pilot; Pilot Not Flying
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: Upon returning from break; the Relief Pilot briefed us that ZZZZ just turned the airport around and that they were now landing to the south. We were then cleared for the ZZZZZ 9A RWY 16L. I pulled up the runway information for [RWY] 16L. A new ATIS reported WET and a tailwind. We discussed this amongst ourselves and decided that I would let ATC know that with the Wet runway and tailwind we would be unable to accept Runway 16L and REQUIRED runway 16R. ATC then re-cleared us to ZZZZ; ZZZZZ 9A; RWY 16R. I programmed the FMC with this new clearance.ATC then cleared us direct to ZZZZZ1; then ZZZZZ2 and prepare to copy holding instructions at ZZZZZ2. The clearance was to hold at ZZZZZ2; our landing time was to be 54 (some 40 minutes into the future). I programmed the FMC with this hold and used the 54 as the EFC time and it showed our landing fuel of 6.0. We all agreed that this was unacceptable and I changed the EFC time to 40; less conservative but more accurate to flow into and landing time of 54. This gave a marginal improvement of 7.2 I believe. We were still not comfortable with this a landing fuel at our destination. (In the meanwhile; the Relief Pilot was on SATCOM with Dispatch. Their advice was that if we were not comfortable with using PAN PAN; they would rather us divert to ZZZZ1 vs ZZZZ2 but that it was up to us.) We discussed this and I informed ATC that we only had 2 mins of hold fuel; we were working with Company Dispatch to see if they preferred a divert to ZZZZ3 or ZZZZ4; unless they had a glimmer of hope for us. ATC paused and responded that they could only give us direct ZZZZ with a PAN; PAN call. We decided to request a clearance to ZZZZ1. ATC gave us a vector out of the hold and an altitude. I programmed the FMC with ZZZZ1 as our new destination. Our clearance was direct ZZZZZ3 then H185 to ZZZZ1. Our new landing fuel at ZZZZ1 now showed 7.1. We were still not cleared to altitude and with the overburn situation; we did not trust going all the way to ZZZZ1. The second Relief Pilot commented that he was not comfortable and that we should declare PAN PAN and go back. We all quickly agreed. I initially declared PAN PAN and requested clearance to ZZZZ2; ATC then reminded me that with the PAN PAN call she could clear us directly to ZZZZ. I thanked her and said that we would rather ZZZZ. We received clearance to ZZZZ; ZZZZZ 9A; GLS to 16R. We conducted a normal approach and landing without further incident.Upon reflection; if I were to do this flight over; here is what I would do differently. We had an unexplained overburn. I am looking forward to finding out the reason for this. We flew our flight plan and there was no wind bust of significance noted and our times were spot on. The airplane acted as if it were heavier than what was loaded into the FMC; since this was a slow steady underscore of fuel burn at every waypoint. We all later commented that from a human factors point of view; if it wasn't for the recent ZZZ/ZZZZ flight that was rumored to land in ZZZZ; [advising ATC] and they got to the gate 'with so much gas'; we would not have been so hesitant to declare PAN PAN; right when ATC explained that we could only get direct ZZZZ with a PAN PAN call. We had all heard about what a big international event this caused with the ZZZZ government that day. Instead; I believe we went overboard the other way; trying to prove that we were reasonable and would work with them and if we had two viable alternates; it would be our first choice. We could have avoided the entire discomfort with trying for ZZZZ1 only to then decide that we were not comfortable and then declared PAN PAN.I do believe that we ran a safe cockpit; everyone's input was triaged and accepted. We landed safely and with gas to go around in the unlikely event we needed to; with safety or urgent condition we declared using PAN PAN.


Second narrative: ATC assigned us a runway change into ZZZZ. We were told to expect landing Runway 16L. Runway 16L performance data showed Runway 16L would be unusable due to wet conditions with a tailwind. We requested [Runway] 16R. They assigned us holding with a touchdown time. We asked for EFC [Expect Further Clearance] time but they could only give us a rough estimate. We asked if they could get us in sooner due to the fact that the time required in holding would possibly cause us to divert. They replied that ZZZZ was only available via a Pan Pan Pan call. We did our calculations for holding as well as calculations for diverting to ZZZZ1 (8.7 landing fuel) and ZZZZ2 (9.2 landing fuel). As we held in our holding pattern; we discussed our options and calculated our safest course of action. At this point; our anticipated fuel at ZZZZ1 was dwindling and was nearing 7.1. We decided that the safest course of action would be to fly to ZZZZ2 (9.0 estimated arrival fuel). With ZZZZ still unavailable; we declared Pan Pan Pan and requested direct ZZZZ2. At that moment; ATC offered us an expedited arrival into ZZZZ. We agreed that we would prefer ZZZZ due to safety and proximity. We landed on Runway 16R with approximately 9.1 in fuel. Flight was completed with no incident.


Synopsis: B787 flight crew reported fuel over burn condition and unable to land on runway in use resulted in crew requesting expedited handling.