Narrative:

I was working departure east at mco. Air carrier X departed the airport, was radar idented and climbed to 8000 ft. Air carrier X read back 8000 ft. Air carrier Y was on the downwind at 9000 ft. Air carrier X climbed through his assigned altitude to 8600 ft and was directly under air carrier Y, who received a TCASII alert and climbed to avoid the air carrier X aircraft.

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Original NASA ASRS Text

Title: ACR X CLB THROUGH ASSIGNED ALT HAD NMAC LTSS FROM ACR Y TCASII RA CLB. EVASIVE ACTION TAKEN. PLTDEV.

Narrative: I WAS WORKING DEP E AT MCO. ACR X DEPARTED THE ARPT, WAS RADAR IDENTED AND CLBED TO 8000 FT. ACR X READ BACK 8000 FT. ACR Y WAS ON THE DOWNWIND AT 9000 FT. ACR X CLBED THROUGH HIS ASSIGNED ALT TO 8600 FT AND WAS DIRECTLY UNDER ACR Y, WHO RECEIVED A TCASII ALERT AND CLBED TO AVOID THE ACR X ACFT.

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.