Commercial Fixed Wing
Flight Crew Last 90 Days 114; Flight Crew Total 9700; Flight Crew Type 7700
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew FLC complied w / Automation / Advisory
Aircraft; Airspace Structure; Procedure; Human Factors; Chart Or Publication
We were on a left downwind at 3;000 ft. Heading 090 approximately 5 miles offset to the south. Shortly after passing abeam the threshold; we were cleared for a Visual Approach. The First Officer put 1;600 ft. in the MCP altitude window (FAF altitude); and after we both verified the altitude; began a descent in FLCH. He bugged clean maneuvering speed and extended the speedbrakes. Around 1 to 2 miles past abeam the Final Approach fix he started a base turn to the left. Descending through 1;900 ft. at 220 kts. we received a CAUTION TERRAIN warning. I quickly glanced outside but did not see any terrain or obstacles. A second later the GPWS started a TERRAIN TERRAIN warning. We immediately initiated the CFIT recovery maneuver. Even though we were VMC; we could not immediately or unequivocally determine that there was not a terrain issue. The moment our descent rate was arrested; the warning stopped. We reached an altitude of 2;900 ft. before discontinuing the CFIT maneuver. We continued the base turn and Visual Approach. The rest of the approach and landing was uneventful. After landing; we remembered seeing hills depicted on the approach chart almost directly south of the final Approach Fix. The day prior we flew the exact approach with no issues. Today; approach control vectored us further to the south before clearing us for a Visual Approach. I typically never set an MCP altitude below 2;000 ft. until on final. This time I believed we had enough altitude and airspeed to lose that setting 1;600 ft. in the MCP window would be ok. That was my mistake. Had we set 2;500 ft. in the MCP window until after turning base; we most likely would not have received a GPWS warning.
Approach's vectoring placed us approximately 5 miles south of the field close to midfield at 3;000 ft. We had just leveled from a descent of 5;000 ft. I had used FLCH as the descent mode from 10;000 ft. I realized we had excessive energy to manage in the descent and approach and I decided to hold airspeed at 245 kts. in an effort to reach 3;000 ft. more efficently. After reaching 3;000 ft. I bugged clean maneuvering speed. The speed brake had been extended the duration of the descent. At a little beyond mid field we were cleared for a Visual Approach. I put 1;600 ft. in the alt window and continued descending in FLCH. Almost simultaneously as the turn to base was begun the warning caution TERRAIN TERRAIN occurred followed by PULL UP PULL UP. Neither of us could unequivocally determine if terrain was in our path. For me the sun and green sun shade was obscuring my vision forward. I don't recall seeing anything other than green on my terrain display. Both pilots had terrain selected. I immediately started the CFIT maneuver. The turn to base was continued and as soon as the descend changed to climb the GPWS warning stopped. The approach and landing continued on profile. I will in the future put more emphasis on terrain features listed on the approach chart during briefings. This will allow me to tailor approach configurations accordingly.
Flight Crew reported receiving a GPWS alert due to their configuration settings.