Narrative:

We were on the runway 9L localizer and GS at mia. A twin turboprop high wing commuter plane on a visual approach to runway 9R at mia overshot final from a right base and passed through our localizer, then returned through the localizer to runway 9R. The other aircraft was, at the closest point, about 50-100 ft in front of us and 100-200 ft above us. Our altitude at the time was about 1000-1500 ft AGL. Later contact with tower personnel revealed that the flight was an air carrier light transport. The captain stated that he was attempting a coupled approach from a 90 degree right base. I would like to note that TCASII sounded an alert, but due to our altitude, our normal response was to reach over and turn off the RA portion as per company policy. However, we are used to getting alerts on approach and have learned to ignore them. This practice, of assuming all alerts to be of no consequence at low altitude on final, appears to be a very bad habit.

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Original NASA ASRS Text

Title: AN ACR MLG HAD AN NMAC WITH AN ACR LTT THAT FLEW THROUGH THE LOC FOR THE PARALLEL RWY.

Narrative: WE WERE ON THE RWY 9L LOC AND GS AT MIA. A TWIN TURBOPROP HIGH WING COMMUTER PLANE ON A VISUAL APCH TO RWY 9R AT MIA OVERSHOT FINAL FROM A R BASE AND PASSED THROUGH OUR LOC, THEN RETURNED THROUGH THE LOC TO RWY 9R. THE OTHER ACFT WAS, AT THE CLOSEST POINT, ABOUT 50-100 FT IN FRONT OF US AND 100-200 FT ABOVE US. OUR ALT AT THE TIME WAS ABOUT 1000-1500 FT AGL. LATER CONTACT WITH TWR PERSONNEL REVEALED THAT THE FLT WAS AN ACR LTT. THE CAPT STATED THAT HE WAS ATTEMPTING A COUPLED APCH FROM A 90 DEG R BASE. I WOULD LIKE TO NOTE THAT TCASII SOUNDED AN ALERT, BUT DUE TO OUR ALT, OUR NORMAL RESPONSE WAS TO REACH OVER AND TURN OFF THE RA PORTION AS PER COMPANY POLICY. HOWEVER, WE ARE USED TO GETTING ALERTS ON APCH AND HAVE LEARNED TO IGNORE THEM. THIS PRACTICE, OF ASSUMING ALL ALERTS TO BE OF NO CONSEQUENCE AT LOW ALT ON FINAL, APPEARS TO BE A VERY BAD HABIT.

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.