Date: 201412
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Citation Excel (C560XL)
Operator: Fractional
Operating under: Part 91
Flight phase: Initial Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Fractional
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Fatigue
Anomaly: Conflict NMAC
Detector: Automation Aircraft RA; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Flight Crew Executed Go Around / Missed Approach; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: At approximately 700 feet MSL while on final approach to runway 36 and after being cleared to land by the local controller; we both recognized at about the same time that there was a target on our TCAS display. It seemed to appear suddenly. Initially; we did not receive a Traffic Advisory (TA) or a Resolution Advisory (RA) associated with the target aircraft. I slowly arrested the descent as we both were trying to determine if the target was above us or below us. Because the target on the TCAS display was close to our aircraft icon symbol on the TCAS display; we could not determine if there was a plus or minus sign next to the vertical distance of the target. I gradually began a shallow climb while adding power. At approximately 900 feet MSL; we received an aural 'monitor vertical speed' TCAS alert. The VSI showed red below and a green arc above 0 VSI. At about the same time that we recognized the target on TCAS display; the controller asked the target aircraft what his position was and the pilot said that he was on final. So much concentration was being made by us to avoid collision that neither of us remember the exact dialog that the local controller was having with the target aircraft pilot. I think that I heard the local controller instruct the target aircraft pilot to turn to the east immediately and that he was told earlier to make a position report 4 miles from the airport. We executed a normal and uneventful landing after the second visual approach. Fatigue may have been a factor in my alertness and not recognizing this aircraft earlier on the TCAS display. I felt rested; but cumulative days of waking up at 2 and 3am body clock time; may have contributed to my alertness level. I think that management should factor in the time zones of the crew members when scheduling early flights especially for West Coast crews. Scheduled later starts/trips should be assigned at least every other or second day to avoid cumulative fatigue. Additionally; avionics manufactures that provide TCAS equipment that incorporate TA's and RA's; should be required to program this equipment to provide aural warnings all the way to the ground. We operate a lot in high impact traffic areas at smaller and often non-towered airports where this feature would be useful and could save lives.




Synopsis: CE560 Captain experiences a NMAC on short final during a day visual approach. An aircraft symbol was detected on TCAS in close proximity with no aural alert and a shallow climb is initiated. At 900 feet a TCAS RA is generated with any descent depicted as red and a go-around is initiated. A VFR aircraft that was told to report four miles; did not and was forgotten by the Tower.