Narrative:

Being vectored into the medium large transport airport area, we were on base for runway 27L and cleared for the visual approach. On turning final, I used the localizer back course for backup and the ground lighting system for the descent. I was hand flying a normal descent and heard a traffic alert on the TCASII. Upon referencing the TCASII screen, we saw the traffic was 300 ft below us and directly off the nose. I looked out and the airplane came into view. It was hard to see because the river was below us and the plane blended in. I arrested my descent immediately and the piper cadet maintained his altitude and we passed over him and he flew underneath us to the north. I don't know if he ever saw us because we were at his 5 O'clock position. He may have seen us after he turned on final for runway 27R which was where he was going. It was pretty scary! If I had continued in my descent on final we would have collided for sure. After listening to the conversation between the cadet and the controller, we found out this: the controller said he instructed the cadet to turn a 360 degree heading (I believe to the south side of the airport). The cadet said he could hear every other controller frequency but he was having trouble hearing the tower frequency. The tower and he discussed it further, tower telling him to get his radio fixed. The situation resulted in no incident -- thankfully. Thanks for the NASA reporting system.

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Original NASA ASRS Text

Title: CRJ ENCOUNTERS TCASII ALERT WITH INTRUDER PIPER CADET ON VISUAL APCH TO MLB.

Narrative: BEING VECTORED INTO THE MLG ARPT AREA, WE WERE ON BASE FOR RWY 27L AND CLRED FOR THE VISUAL APCH. ON TURNING FINAL, I USED THE LOC BACK COURSE FOR BACKUP AND THE GND LIGHTING SYS FOR THE DSCNT. I WAS HAND FLYING A NORMAL DSCNT AND HEARD A TFC ALERT ON THE TCASII. UPON REFING THE TCASII SCREEN, WE SAW THE TFC WAS 300 FT BELOW US AND DIRECTLY OFF THE NOSE. I LOOKED OUT AND THE AIRPLANE CAME INTO VIEW. IT WAS HARD TO SEE BECAUSE THE RIVER WAS BELOW US AND THE PLANE BLENDED IN. I ARRESTED MY DSCNT IMMEDIATELY AND THE PIPER CADET MAINTAINED HIS ALT AND WE PASSED OVER HIM AND HE FLEW UNDERNEATH US TO THE N. I DON'T KNOW IF HE EVER SAW US BECAUSE WE WERE AT HIS 5 O'CLOCK POS. HE MAY HAVE SEEN US AFTER HE TURNED ON FINAL FOR RWY 27R WHICH WAS WHERE HE WAS GOING. IT WAS PRETTY SCARY! IF I HAD CONTINUED IN MY DSCNT ON FINAL WE WOULD HAVE COLLIDED FOR SURE. AFTER LISTENING TO THE CONVERSATION BTWN THE CADET AND THE CTLR, WE FOUND OUT THIS: THE CTLR SAID HE INSTRUCTED THE CADET TO TURN A 360 DEG HDG (I BELIEVE TO THE S SIDE OF THE ARPT). THE CADET SAID HE COULD HEAR EVERY OTHER CTLR FREQ BUT HE WAS HAVING TROUBLE HEARING THE TWR FREQ. THE TWR AND HE DISCUSSED IT FURTHER, TWR TELLING HIM TO GET HIS RADIO FIXED. THE SIT RESULTED IN NO INCIDENT -- THANKFULLY. THANKS FOR THE NASA RPTING SYS.

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.