Flight crew arriving SLLP and cleared for the ILS Z Runway 10 approach reports TCAS RA and NMAC with aircraft climbing under them on the PAZ 305 radial. A maximum rate climb and maneuvering eventually results in a clear of conflict TCAS announcement.
Synopsis
Flight crew arriving SLLP and cleared for the ILS Z Runway 10 approach reports TCAS RA and NMAC with aircraft climbing under them on the PAZ 305 radial. A maximum rate climb and maneuvering eventually results in a clear of conflict TCAS announcement.
Narrative
We were cleared for the ILS Z approach to Runway 10; as we passed the PAZ VOR outbound we began our descent from the initial approach altitude of 18;000 FT to 15;000 FT. At approximately 4 miles from the VOR; on the outbound leg; traffic popped up and was observed on TCAS by the First Officer. We weren't able to get a visual since the aircraft was almost directly below us. We were descending at approximately 800 to 1;000 FT per minute. I started to level our aircraft at approximately 15;500 FT. At this point the other aircraft started a rapid climb in our direction. Within a couple of seconds we got an R/A from our TCAS commanding a climb. I immediately disconnected the auto pilot and auto throttles and pitched up so as to keep the aircraft in the green on the vertical speed indicator. There were 2 green dots at the top of the indicator; the rest was red. I used max power and had to peg the VSI (6;000 FPM) to out climb the threat. The aircraft was still converging at [such] a rate that we all were anticipating contact. The aircraft came within 200 FT of our underbelly. Once we determined the aircraft was no longer a threat I leveled our aircraft at approximately 19;500 FT; performed a descending 360 degree turn to get back to the initial approach altitude; and then completed the ILS approach. We never saw the other aircraft.
Second reporter narrative
On initial approach we received a TCAS resolution advisory to climb for conflicting traffic. We were cleared the ILS Z Runway 10 approach. We received advisory on outbound leg passing PAX VOR while descending from 18;000 FT to 15;000 FT at approximately 16;000 FT. Autopilot/auto throttles were both disengaged and we performed a max angle/power climb to green VVI indicator range to clear the threat. We climbed to approximately 19;500 FT to clear the conflict aircraft. We were in VMC conditions and the conflict aircraft came within 200 FT of our aircraft; however; it was never spotted. We were never advised of any other aircraft in the area. Additionally; ATC communications was intermittent. Approach was re-initiated and completed successfully without any further conflicts.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.