ERJ 170 flight crew reported an aircraft generated CAUTION OBSTACLE message; due to too low on a visual approach. Flight crew leveled off; then continued approach.
Synopsis
ERJ 170 flight crew reported an aircraft generated CAUTION OBSTACLE message; due to too low on a visual approach. Flight crew leveled off; then continued approach.
Narrative
We were direct ZZZZZ (FAF) and subsequently cleared for the visual XXL in ZZZ. I configured the aircraft early as the smart turn would have us on a very short final to XXL. 3000 ft. was set for ZZZZZ but after realizing that the intercept angle would be greater than 90 degrees; I decided to commence the descent early setting 2000 ft. as the bottom altitude as we would be well past ZZZZZ by the time we were on the straight in and would thus be high and unstable on the approach if we remained at 3000 ft. Upon turning final; we received an obstacle caution and I disconnected autopilot; leveled off at 2000 ft. and subsequently initiated a climb. At 2100 ft.; we were clear of the obstacle before I was able to get the TOGA button engaged so we leveled off intercepted the glide slope and landed uneventfully. Suggestions: ATC could send us direct to a fix outside the final approach fix to allow more time for a stabilized approach to be achieved when coming in for an approach with a large intercept angle. Additional training could be conducted for flying visual approaches at night in the simulator. Abnormal surprise situations could be practiced in the simulator.
Second reporter narrative
On our descent to ZZZ we were transferred to ZZZ Approach; we were at 6000 ft. ZZZ Approach had us descend to 4000 ft. and direct to ZZZZZ which is the final approach fix to Runway XXL at ZZZ. We proceeded and entered direct to ZZZZZ in the FMS. This of course would draw out a smart turn from ZZZZZ without actually flying to/over the fix. As we got closer to the airport; we were asked if we had the field in sight which we had for awhile. We were then cleared for the visual approach into XXL. We set 3000 ft. for the final altitude over ZZZZZ. As we got closer we realized that we had too much of an angle going into ZZZZZ and that would have created a dive when the aircraft would capture the approach so the decision was made to descend below the published altitude of 3000 ft. in order to get a normal descent into the approach and landing. I believe the altitude set was 2000 ft . We were already configured for landing prior to reaching the final approach fix and totally in visual conditions. We started to descend below 3000 ft. just prior to ZZZZZ and as we were in the turn toward the runway we received a CAUTION OBSTACLE message. The message was heard once. We immediately leveled off momentarily just as we were getting lined up. I immediately looked down at our altitude and found ourselves reading 700 ft. on the RA. After our momentary level off we recaptured the PAPI and landed without any other further issues.After reaching the gate we looked further into the approach and where we went wrong here. Our decision to continue to fly direct to ZZZZZ was our first error. After being given the visual; we should have just flown out somewhere outside of the final approach fix and then intercept the course further out to give us ample time to be in a proper position to intercept the final approach course at a good altitude. The other major error was the decision to descend below 3000 ft. This put us closer to the ground and to obstacles (towers) that were in the area. And finally; by getting ourselves in this un-established approach; we should have gone around.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.