E175 flight crew reported a GPWS Too Low Terrain Warning on approach to a non-towered airport after cancelling IFR and recommended more training to be given for special airports such as this one.

Date: 2022-01 · Aircraft: EMB ERJ 170/175 ER/LR · Phase: approach

Anomalies: deviation-altitude-crossing-restriction-not-met|deviation-discrepancy-procedural-far|deviation-discrepancy-procedural-clearance|deviation-discrepancy-procedural-published-material-policy|inflight-event-encounter-cftt-cfit

Synopsis

E175 flight crew reported a GPWS Too Low Terrain Warning on approach to a non-towered airport after cancelling IFR and recommended more training to be given for special airports such as this one.

Narrative

Flight from ZZZ to ZZZZ; routine through the departure and enroute phases of flight. Planning on landing on Runway XX visually; using the RNAV approach as reference. It was my first time flying into ZZZZ and the Captain had briefed me that this would be different than most operations I was used to. Descending as we approached ZZZZ; Captain asked me to cancel our IFR as we were able to maintain VFR. I complied and we were handed off from Approach to the field's UNICOM. As we began our approach; we noticed a small rain shower over where the field is located. We briefed the possibility of abandoning our approach if the rain affected our ability to see the runway. Around this time an aircraft landing in front of us called us over UNICOM to inform us that they had no issues on their approach to land and they reported improved conditions from what we previously expected.The Captain; who was flying; began a descent and I noticed he was starting to descend below the 2;300 ft. altitude at ZZZZZ." I spoke up and reminded him of the altitude at that waypoint and he took corrective action. Passing ZZZZZ on final for the runway; he began another descent; this time down to an altitude of around 600 ft. roughly 4 miles from the runway; and it was at this time that I was able to clearly see the runway and called it in sight. However; the Captain had seen it before me since I was not familiar with this airport. Although we were still maintaining VFR; this descent put us about 600 ft. above the water still roughly 4 miles from the runway. Passing the FAF; the Captain continued down to the published minimums for the approach; rounded up to 400 ft. It was at this altitude over the land that we received a GPWS alert. This surprised us both as we were above published minimums and had visual of the runway and all land and obstacle between us and the runway in sight. The alert disappeared as I looked and noticed my RA showed 400 ft.; still above published minimums. With the alert gone [and] runway and all terrain in sight; we continued our approach to land and the remainder of the flight was uneventful.This was my first time flying into ZZZZ2; including ZZZZ; and at the time only had 60 hours in the aircraft as a First Officer. The Captain previously elected earlier in the trip to fly both legs into and out of ZZZZ since it presents unique challenges being an uncontrolled; short runway; island airport in ZZZZ2 with unique weather requirements for dispatch. During the flight the Captain explained how different this flight would be compared to what I was used to in my short time at the airline. This prepared me to expect some differences; especially in the approach to landing phase of flight. The Captain briefed me his plans for the approach; including approaching the field VFR. Starting the descent early to 600 ft. was something that I rationalized to myself as being part of the differences to be expected as the Captain previously explained why he was doing so. This resulted in us flying lower to the ocean further out from the runway than we should have been and likely the reason for the GPWS alert upon reaching our rounded minimums after the FAF being referenced.Looking back; even though it was my first time flying into this unique operating environment with an experienced Captain; I should have been more aware of how low we were compared to how far we were from the runway and queried the Captain further on this and call for the approach to be abandoned. During our post-flight debrief I brought up the GPWS alert and asked if this was something we should report and the Captain assured me it was not necessary and dismissed this as saying he could just explain what he was doing to whoever might ask. Going forward I know this should not be the case and reports should be filed if there is any question of their need or warrant.I would welcome additional training for operations into international airports such as ZZZZ which have unique operationalchallenges and potential hazards; especially for relatively inexperienced new first officers like myself."

Second reporter narrative

Arrival into ZZZZ is VFR only for our company aircraft. Island in sight and IFR cancelled at 5000 ft. in the descent. Pilot report from aircraft landing 5 minutes before us was visual with runway on the approach above 1000 ft. Since we were VFR; we needed to remain VMC; so we used the lateral guidance of the RNAV approach and configured for approach and landing early. I had the field in sight and descended for cloud clearance along the approach path. Once inside the final approach fix inbound; I descended to 400 ft. as that was the MDA. In visual conditions the GWPS alert too low; terrain" sounded. Both pilots had visual contact with terrain with no obstacles along our path. I clicked off the autopilot to react if a go-around or maneuvering would be necessary. We continued inbound and landed Runway XX with no further incident.Numerous scattered layers of clouds in the area; but visual with the area and the pilot report gave us the impression that the weather would be adequate. I request further training in company procedures in ZZZZ2. VMC arrivals in a regional jet are problematic but required by company policy."

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.