A320 captain reported a near midair collision encounter on final approach.

Attributes
ACN	1580313
Time
Date	201809
Local Time Of Day	1201-1800
Place
Locale Reference	SJC.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Bonanza 33
Operating Under FAR Part	Part 91
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 240 Flight Crew Total 1286 Flight Crew Type 1286
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 500 Vertical 300

Narrative:

On the Razzr4 arrival and cleared for the ILS 30L; as we were nearly turning onto final a bonanza aircraft passed about 200-300 feet below and about 500 feet laterally under our left wing. There was no TCAS warning and I asked norcal approach about the bonanza; he replied that there was no transponder information but that there was only primary painted information.

Original NASA ASRS Text

Title: A320 Captain reported a near midair collision encounter on final approach.

Narrative: On the Razzr4 arrival and cleared for the ILS 30L; as we were nearly turning onto final a Bonanza aircraft passed about 200-300 feet below and about 500 feet laterally under our left wing. There was no TCAS warning and I asked NorCal approach about the Bonanza; he replied that there was no transponder information but that there was only primary painted information.

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.