Small Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 3500; Flight Crew Type 1000
Confusion; Distraction
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Environment - Non Weather Related; Procedure
While on a visual approach for Runway 20R and after being cleared to land; with the autopilot engaged and flying the ILS; a primary target appeared to be under me and crossing from my right to left. The target quickly changed from yellow to red and the aural TCAS alert to 'Climb; Climb' annunciated. I turned off the autopilot and initiated a pitch attitude to bring the rate of climb to the green area of resolution on the VSI. Then; as quickly as it appeared; the target was gone. Being single pilot and on short final; I didn't have the presence of mind to report to ATC the RA. Once on the ground; I asked ground control for a number to the tower. Upon my call to tower; I explained what had happened. They said there is 'an avionics shop about in the vicinity' of where I received the RA. They said it has been an issue in the past; but they are unable to predict when to caution pilots of this anomaly as it is sporadic and infrequent. The controller confirmed the active controller recalled my clearance to land and confirmed (through the individual I was on the phone with) that there was no traffic under me during my final approach.
A corporate pilot reported receiving a TCAS climb RA at 1;000 feet on the SNA Runway 20 visual approach. After landing he learned an avionics shop in the vicinity of his alert causes occasional false TCAS alerts.