Narrative:

Event: a near miss with light transport at msy. We were on a heading of 220 degree at 3000 MSL in moderate rain, in an area of small cumulus buildups. Our in-flight visibility was 1 1/2 mi and we were in and out of the clouds. Our approach controller said 'turn right 320 now for traffic'. We immediately turned and were in the first few degrees of a 25 degree bank turn when we saw the small transport pass under and to our right side. He appeared to be within 100' vertical and almost directly under the cockpit area of our medium large transport. The light transport appeared to be in a nose down, descending attitude. Shortly after, we were cleared for the approach. After landing several passenger commented on the near miss. I phoned approach from operations. They thought the light transport had misunderstood his ATC clearance from new orleans lake front, and busted his altitude. Suggestion: dispense with the practice of just reading back the transponder code as acknowledgement for ATC clearance. Return to a readback of the initial altitude on your ATC clearance!

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Original NASA ASRS Text

Title: ACR MLG ON ARR INTO MSY HAS NMAC WITH CORP LTT ON ARR INTO MSY.

Narrative: EVENT: A NEAR MISS WITH LTT AT MSY. WE WERE ON A HDG OF 220 DEG AT 3000 MSL IN MODERATE RAIN, IN AN AREA OF SMALL CUMULUS BUILDUPS. OUR INFLT VISIBILITY WAS 1 1/2 MI AND WE WERE IN AND OUT OF THE CLOUDS. OUR APCH CTLR SAID 'TURN RIGHT 320 NOW FOR TFC'. WE IMMEDIATELY TURNED AND WERE IN THE FIRST FEW DEGREES OF A 25 DEG BANK TURN WHEN WE SAW THE SMT PASS UNDER AND TO OUR RIGHT SIDE. HE APPEARED TO BE WITHIN 100' VERTICAL AND ALMOST DIRECTLY UNDER THE COCKPIT AREA OF OUR MLG. THE LTT APPEARED TO BE IN A NOSE DOWN, DESCENDING ATTITUDE. SHORTLY AFTER, WE WERE CLRED FOR THE APCH. AFTER LNDG SEVERAL PAX COMMENTED ON THE NEAR MISS. I PHONED APCH FROM OPERATIONS. THEY THOUGHT THE LTT HAD MISUNDERSTOOD HIS ATC CLRNC FROM NEW ORLEANS LAKE FRONT, AND BUSTED HIS ALT. SUGGESTION: DISPENSE WITH THE PRACTICE OF JUST READING BACK THE XPONDER CODE AS ACKNOWLEDGEMENT FOR ATC CLRNC. RETURN TO A READBACK OF THE INITIAL ALT ON YOUR ATC CLRNC!

Data retrieved from NASA's ASRS site as of August 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.