Narrative:

After being vectored to a visual approach to mlb; we were cleared for the visual and cleared to land runway 27L and were on a right downwind. First officer was the pilot flying and continued downwind leg past the numbers and was intending to turn base just inside the OM. We were at pattern altitude of 1500 ft. About 2-3 miles past the upwind numbers mlb tower called helicopter traffic 11 o'clock and less than a half mile. While searching controller called again; same traffic at 1/4 mile; then less than a quarter mile. Just at this time the very small helicopter came into view probably no more than 500 ft away same altitude on a perpendicular converging course as if he was on a right base to 27L. GPWS gave a TA; it had not seen traffic until this time. Then almost immediately as I had first officer disconnect autopilot and turn right; the GPWS gave a descending RA. First officer executed the turn complied with RA and this allowed us to avoid the traffic and continue into a right base and normal landing. Following arrival at gate; I called approach and spoke with the supervisor. The supervisor indicated there was a coordinated procedure between patrick AFB and mlb tower to depart helicopters from patrick across the mlb airspace and apparently someone had dropped the ball in this particular instance. I was compelled to agree and told him about our descending RA from 1500 ft while in the traffic pattern and extreme close proximity to the helicopter. I also informed him we considered the incident a near mid-air. He told me an investigation would be initiated as they did with all RA's in their airspace. Response; right turn away from traffic and complied with descending RA.

Related reports:

Google
 

Original NASA ASRS Text

Title: Air carrier on a visual approach to MLB received a TCAS/RA from helicopter over flight traffic that was issued by ATC; the reporter indicating the ATC procedure utilized needed review and improved over sight.

Narrative: After being vectored to a visual approach to MLB; we were cleared for the visual and cleared to land Runway 27L and were on a right downwind. First Officer was the pilot flying and continued downwind leg past the numbers and was intending to turn base just inside the OM. We were at pattern altitude of 1500 FT. About 2-3 miles past the upwind numbers MLB Tower called helicopter traffic 11 o'clock and less than a half mile. While searching Controller called again; same traffic at 1/4 mile; then less than a quarter mile. Just at this time the very small helicopter came into view probably no more than 500 FT away same altitude on a perpendicular converging course as if he was on a right base to 27L. GPWS gave a TA; it had not seen traffic until this time. Then almost immediately as I had First Officer disconnect autopilot and turn right; the GPWS gave a descending RA. First Officer executed the turn complied with RA and this allowed us to avoid the traffic and continue into a right base and normal landing. Following arrival at gate; I called Approach and spoke with the Supervisor. The Supervisor indicated there was a coordinated procedure between Patrick AFB and MLB Tower to depart helicopters from Patrick across the MLB airspace and apparently someone had dropped the ball in this particular instance. I was compelled to agree and told him about our descending RA from 1500 FT while in the traffic pattern and extreme close proximity to the helicopter. I also informed him we considered the incident a near mid-air. He told me an investigation would be initiated as they did with all RA's in their airspace. Response; right turn away from traffic and complied with descending RA.

Data retrieved from NASA's ASRS site as of April 2012 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.