Date: 202110
Local time of day: 1801-2400
Location: ZZZ.Tower, US
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: GPWS
Component problem: Malfunctioning
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: Workload; Distraction
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning; Person Flight Crew
When detected: In-flight
Result: Aircraft Equipment Problem Dissipated; Flight Crew Took Evasive Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I was First Officer and Pilot Flying on this flight. The Captain was Pilot Monitoring; and the other First Officer was in the third seat. We were in actual instrument conditions; and fully set up and stabilized on the ILS to Runway XX at ZZZ. Somewhere between the GS intercept; ZZZZZ; and Runway XX; we received a GPWS 'Too Low; Terrain' aural alert and light. We all checked and saw that we were on localizer; glideslope; and airspeed. We were fully configured and stable. As soon as we determined this; the 'Too Low; Terrain' aural alert sounded again. Since we were still in actual instrument conditions at night and could not see if there was an obstacle on the approach; I called 'Go-Around; Flaps 20'. We executed the missed approach instructions given to us by ATC. We then requested vectors for the ILS to Runway XY at ZZZ. While setting up for and briefing this approach; we decided that if we got another GPWS message; or anything else seemed unsafe; we would divert to ZZZ1; where the weather conditions were better. We flew the ILS to [Runway] XY without any GPWS alert; and safely landed on Runway XY at ZZZ. We made a report to ZZZ tower about what had happened with our GPWS. A government aircraft made the same approach and successful landing using the ILS to Runway XX after we had done the missed approach. They had no issues with their GPWS. It is possible that our GPWS alert was triggered by an equipment malfunction; however; it was the safe choice to go missed in these conditions. We flew the profile like we train in the simulator. We had to go missed; set up for an approach in the opposite direction; and landed in a direct crosswind. I would suggest adding this scenario at ZZZ with the GPWS alert to one of our simulator lessons.


Second narrative: We were on the ILS Runway XX into ZZZ. We were fully configured flaps 25; on localizer and glide path; and stable through 1;000 ft. The winds were a direct crosswind and gusty. At approximately 800 ft. we received the GPWS aural alert Too Low Terrain. We were still in the clouds at this time. We called Go Around and we executed the go around. The go around went smoothly. ATC asked why we went around and our intentions. We asked to be vectored back around for the ILS Runway XY. Because it was a direct crosswind and we were not sure why we received the GPWS we all agreed it would be a good idea to try the other approach to the opposite runway. We got vectors and set up for the approach. The approach to ILS Runway XY went smoothly without any problems and we landed Runway XY.I'm not sure why we received the GPWS alert. We were on localizer; glide path; speed; and fully configured.


Synopsis: B767 flight crew reported a GPWS 'Too Low; Terrain'  alert during IFR approach in a stabilized condition. Flight crew executed a 'Go Around'. Flight crew then requested another approach which was completed safely with no further issues.