Narrative:

Flying a 727 we were level at 3000 ft 15 mi from the airport. They cleared us down to 1700 ft in preparation for the 'lagoon visual approach.' which we have always thought was a 'protected altitude over the smaller airport 6 mi to the west of the sju airport. They are restr to 1200 ft. As we were almost 10-11 mi out on a 'dog-leg' to final, we advised we had the airport in sight. He advised us to 'maintain 1700 ft until intercepting the lagoon visual approach. Cleared for the lagoon visual, contact the tower 118.3,' while we did. Continuing down through 300 ft, I happened to look at the TCASII and noticed an aircraft 11:30 to 12 O'clock 3 mi at 200 ft which at the same time the TCASII said 'traffic, traffic.' I advised the first officer I had the aircraft (we were at 2100 ft at this time). I received a RA 'monitor vertical speed through climb,' which I had already cleared. We were at 2400 ft when a comanche went under us at about 2000 ft. We were in the process of switching to tower when this happened, and advised the tower we were in climb because of a TCASII advisory. He advised us to call the tower on the ground, which we did. They had apparently cleared the aircraft on a departure and was cleared to 2000 ft on the departure. However, I found out later that the aircraft was normally limited to 1200 ft at that satellite airport. Close call. TCASII did a good job.

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Original NASA ASRS Text

Title: ACR HAS NMAC WITH SMA.

Narrative: FLYING A 727 WE WERE LEVEL AT 3000 FT 15 MI FROM THE ARPT. THEY CLRED US DOWN TO 1700 FT IN PREPARATION FOR THE 'LAGOON VISUAL APCH.' WHICH WE HAVE ALWAYS THOUGHT WAS A 'PROTECTED ALT OVER THE SMALLER ARPT 6 MI TO THE W OF THE SJU ARPT. THEY ARE RESTR TO 1200 FT. AS WE WERE ALMOST 10-11 MI OUT ON A 'DOG-LEG' TO FINAL, WE ADVISED WE HAD THE ARPT IN SIGHT. HE ADVISED US TO 'MAINTAIN 1700 FT UNTIL INTERCEPTING THE LAGOON VISUAL APCH. CLRED FOR THE LAGOON VISUAL, CONTACT THE TWR 118.3,' WHILE WE DID. CONTINUING DOWN THROUGH 300 FT, I HAPPENED TO LOOK AT THE TCASII AND NOTICED AN ACFT 11:30 TO 12 O'CLOCK 3 MI AT 200 FT WHICH AT THE SAME TIME THE TCASII SAID 'TFC, TFC.' I ADVISED THE FO I HAD THE ACFT (WE WERE AT 2100 FT AT THIS TIME). I RECEIVED A RA 'MONITOR VERT SPD THROUGH CLB,' WHICH I HAD ALREADY CLRED. WE WERE AT 2400 FT WHEN A COMANCHE WENT UNDER US AT ABOUT 2000 FT. WE WERE IN THE PROCESS OF SWITCHING TO TWR WHEN THIS HAPPENED, AND ADVISED THE TWR WE WERE IN CLB BECAUSE OF A TCASII ADVISORY. HE ADVISED US TO CALL THE TWR ON THE GND, WHICH WE DID. THEY HAD APPARENTLY CLRED THE ACFT ON A DEP AND WAS CLRED TO 2000 FT ON THE DEP. HOWEVER, I FOUND OUT LATER THAT THE ACFT WAS NORMALLY LIMITED TO 1200 FT AT THAT SATELLITE ARPT. CLOSE CALL. TCASII DID A GOOD JOB.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.