B737-700 captain experiences a TCAS TA on final approach to sna and goes around. On the second appro...

Narrative:

While on final to sna (less than 5 miles from airport) and in the landing configuration we received a TCAS TA at our 12 o'clock and 300 ft below. We quickly searched the area and could not see the intruder. We opted to perform a go-around to avoid getting an RA in close and low. Upon return to the airport; I notified the tower of the reason for the go-around. He said that there was no observed traffic between us and the airport at the time of our go-around. He said that other aircraft had also reported getting TA's on final (no times or dates given). He referred to this as a 'phantom' TA or 'ghost' TA or something of the sort. I have never experienced the phenomenon of a 'ghost' TCAS signal at any other airport. I wonder if there could be a TCAS signal being generated by something other than an aircraft somewhere close to the airport; perhaps by a tech company; test/manufacturing facility or drone. If so; this should be corrected or made known to aircrews. Apparently more than one aircraft has experienced this during a critical landing phase of flight in a high density traffic area.

Original NASA ASRS Text

Title: B737-700 Captain experiences a TCAS TA on final approach to SNA and goes around. On the second approach; ATC advises that there was no traffic at the time of the go-around; but other aircraft have reported phantom TA's in the same location.

Narrative: While on final to SNA (less than 5 miles from airport) and in the landing configuration we received a TCAS TA at our 12 o'clock and 300 FT below. We quickly searched the area and could not see the intruder. We opted to perform a go-around to avoid getting an RA in close and low. Upon return to the airport; I notified the Tower of the reason for the go-around. He said that there was no observed traffic between us and the airport at the time of our go-around. He said that other aircraft had also reported getting TA's on final (no times or dates given). He referred to this as a 'phantom' TA or 'ghost' TA or something of the sort. I have never experienced the phenomenon of a 'ghost' TCAS signal at any other airport. I wonder if there could be a TCAS signal being generated by something other than an aircraft somewhere close to the airport; perhaps by a tech company; test/manufacturing facility or drone. If so; this should be corrected or made known to aircrews. Apparently more than one aircraft has experienced this during a critical landing phase of flight in a high density traffic area.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1189141
Time
Date	201407
Local Time Of Day	1201-1800
Place
Locale Reference	SNA.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Component
Aircraft Component	Traffic Collision Avoidance System (TCAS)
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 192
Events
Anomaly	Inflight Event / Encounter Other / Unknown

B737-700 captain experiences a TCAS TA on final approach to sna and goes around. On the second approach; ATC advises that there was no traffic at the time of the go-around; but other aircraft have reported phantom TA's in the same location.