A320 first officer reported an near midair collision with another aircraft on approach to land.

Attributes
ACN	1697639
Time
Date	201910
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Person 1
Function	First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 11500 Flight Crew Type 3137
Events
Anomaly	Conflict NMAC

Narrative:

On approach to 16L [company X] on 16R appeared to overshoot the localizer (localizer) twice the second time causing the resolution advisory. We responded immediately and re-acquired the [company X] jet (it appeared to very nearly end up underneath us). The auto pilot was off and we were in VMC. After we were clear of the conflict; I descended and reacquired the glide slope and flew a stabilized approach to the runway.

Original NASA ASRS Text

Title: A320 First Officer reported an NMAC with another aircraft on approach to land.

Narrative: On approach to 16L [Company X] on 16R appeared to overshoot the LOC (Localizer) twice the second time causing the Resolution Advisory. We responded immediately and re-acquired the [Company X] jet (it appeared to very nearly end up underneath us). The auto pilot was off and we were in VMC. After we were clear of the conflict; I descended and reacquired the glide slope and flew a stabilized approach to the runway.

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.