Narrative:

Takeoff mia runway 9L, assigned heading 120 degrees and climb to 5000 ft. Passing through approximately 4000 ft MSL, we visually acquired air carrier Y who had taken off on runway 12 just prior to us. As we were monitoring him visually and on TCASII, he began a l-hand turn that appeared to take him in the close vicinity of our projected flight path. We began a transition from our climb to a descent to 3000 ft MSL while simultaneously receiving an aural TA of traffic. We advised mia tower of our deviation and they said they thought they had already sent us to mia departure. Upon contact with departure control and clear of the air carrier Y traffic, we were directed to resume our normal climb profile. Supplemental information from acn 413784: as we climbed out we noticed an S80 had departed runway 12 ahead of us and was at 2 O'clock and 2.5 mi, 400 ft above. At about 3800 ft, I noticed the S80 start a left turn. I elected to deviate from the clearance prior to the receipt of the RA due to the obvious geometry of the situation -- the S80 was turning across our flight path. We had a greater climb rate and we both were about to enter the clouds.

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Original NASA ASRS Text

Title: ACR A300 FLC INITIATES EVASIVE MANEUVER ON DEP WHEN PREVIOUS DEP IS OBSERVED TURNING IN FRONT OF THEM. A300 FLC DSNDS TO MANEUVER CLR OF XING, CLBING TFC. A300 FLC REQUESTS FURTHER CLRNC FROM TWR CTLR, WHO THOUGHT THEY HAD CHANGED ACFT TO TRACON DEP CTL. CLRING TFC, THE A300 RESUMED NORMAL CLB.

Narrative: TKOF MIA RWY 9L, ASSIGNED HDG 120 DEGS AND CLB TO 5000 FT. PASSING THROUGH APPROX 4000 FT MSL, WE VISUALLY ACQUIRED ACR Y WHO HAD TAKEN OFF ON RWY 12 JUST PRIOR TO US. AS WE WERE MONITORING HIM VISUALLY AND ON TCASII, HE BEGAN A L-HAND TURN THAT APPEARED TO TAKE HIM IN THE CLOSE VICINITY OF OUR PROJECTED FLT PATH. WE BEGAN A TRANSITION FROM OUR CLB TO A DSCNT TO 3000 FT MSL WHILE SIMULTANEOUSLY RECEIVING AN AURAL TA OF TFC. WE ADVISED MIA TWR OF OUR DEV AND THEY SAID THEY THOUGHT THEY HAD ALREADY SENT US TO MIA DEP. UPON CONTACT WITH DEP CTL AND CLR OF THE ACR Y TFC, WE WERE DIRECTED TO RESUME OUR NORMAL CLB PROFILE. SUPPLEMENTAL INFO FROM ACN 413784: AS WE CLBED OUT WE NOTICED AN S80 HAD DEPARTED RWY 12 AHEAD OF US AND WAS AT 2 O'CLOCK AND 2.5 MI, 400 FT ABOVE. AT ABOUT 3800 FT, I NOTICED THE S80 START A L TURN. I ELECTED TO DEVIATE FROM THE CLRNC PRIOR TO THE RECEIPT OF THE RA DUE TO THE OBVIOUS GEOMETRY OF THE SIT -- THE S80 WAS TURNING ACROSS OUR FLT PATH. WE HAD A GREATER CLB RATE AND WE BOTH WERE ABOUT TO ENTER THE CLOUDS.

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.