Date: 201406
Local time of day: 1201-1800
Location: SGJ.Airport, FL
Flight conditions: VMC
Weather elements / visibility: Haze / Smoke; 7
Light: Daylight
Aircraft: Light Transport; Low Wing; 2 Turbojet Eng
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class D SGJ
ATC / advisory: Tower SGJ
Second aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Reporter organization: Air Taxi
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude
Detector: Automation Aircraft RA; Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Airport; Procedure
Primary problem: Procedure

Narrative: Arriving in the SGJ area we were kept high by approach. We were advised to expect the visual to 31. The PF briefed the approach and I loaded the ILS 31 into the FMS to back up the visual for situational awareness. Nav radios were appropriately set and checklists completed up to Before Landing. When we were given our descent; the use of spoilers was necessary to be at an altitude for a normal approach reaching the terminal area. We were approaching from the north and there was plenty of room to get down and set up for Runway 31. This was done; as has been necessary at other times in the past; without any abnormality. Just outside the Class D we were cleared for the visual [Runway] 31 and issued a frequency change to Tower. Upon checking in with the Tower we were advised the wind had shifted to the southeast; giving us a tailwind component on landing of around 7 KTS. The Tower offered Runway 13 as an alternative. After a very brief discussion of the situation; we accepted [Runway] 13 and were cleared to land as we turned downwind. I quickly changed the approach to the GPS 13 in the FMS. The pilot flying was slowing the aircraft and calling for the appropriate configurations; which I accomplished. He then called for Before Landing Checklist which I began. As I was doing this I noticed a target on the TCAS northwest of our position by several miles within several hundred feet of our altitude and appearing not to move much. I pointed it out to the pilot flying as we continued downwind. We couldn't visually pick out the aircraft; but monitored the TCAS. As we began turning base; it appeared as though the target was now quickly converging from our 12 o'clock position moving south to southwest at our altitude. He was roughly 2 miles away and we still could not see him. As this was happening the Tower was issuing a traffic advisory to a Cirrus about us in the downwind. Taking into account the rapid closure rate; the appearance that completing the base turn would cause a converging traffic conflict; the proximity of our altitudes; and no visual contact; we agreed the best course of action would be to climb and turn right to avoid the Cirrus. As we maneuvered; the Tower was finishing his communication with the small aircraft and queried if we had turned base. I explained we were turning to avoid the other aircraft. This was the first advisory we had received regarding the other aircraft. The pilot flying saw the aircraft as we were climbing; which I saw a second later at our 1-2 o'clock position. We then received a climb RA. The other aircraft passed below us by about 400 FT and both aircraft had visual contact at this point. We were re-sequenced as number two behind the small aircraft and told to slow to approach speed. The pilot flying slowed to approach speed as I completed the Before Landing Checklist. While we were on final it became evident to the Controller that the spacing wouldn't work. He advised the small aircraft to break off the approach and reenter behind us; and we were cleared to land as number one once more. We landed and taxied in without abnormalities. Post-flight the pilot flying and I discussed the event and couldn't recall a single time we were given and advisory about the traffic until there was a conflict and we took action. It is possible that we didn't hear the other aircraft on frequency because we were busy setting up for the runway change. However; we never received any direct information from the Tower.This event served as an effective reminder that a TCAS display is not very accurate regarding azimuth of traffic and should not be relied upon when searching visually. It was probably 45 degrees in error as to where the traffic actually was. The TCAS tested normally before and after the flight. If I had been a second earlier in attempting to communicate with the Tower when the conflict was discovered; perhaps we would have had a better idea of where the traffic was exactly. This would've aidedin acquiring it visually. By the time I tried to call the Tower he had already begun transmitting to the Cirrus. If there is ever a doubt about traffic or anything else; don't hesitate to ask. I would add that on a visual approach; scanning for traffic is more critical than backing it up with an instrument approach. In the future we will prioritize to bring the workload down. With advances in technology; we have to ensure they don't become hindrances to basic airmanship. I wonder if I would have seen the traffic sooner if I hadn't been reprogramming the FMS. Fly the airplane first.




Synopsis: An air taxi Captain on a SGJ Runway 13 visual approach had an airborne conflict and took evasive action from an aircraft ATC was talking with. TCAS issued a RA about the traffic but ATC never issued that aircraft as traffic.