B787 Dreamliner Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 118; Flight Crew Total 16865; Flight Crew Type 118
Communication Breakdown; Confusion; Situational Awareness
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Human Factors
We were cleared for the approach to fly the ILS 16R procedure. Near the MERYN intersection approach called out traffic on a dog leg to 16L. We were very busy at this point in the approach and I stated to the PM I had traffic behind us approaching 16L which was the logical but wrong assumption. A very short time later we get an immediate and simultaneous TA and RA which I responded to staying within the advisory bars and then noticed; incredulously; a 737 passing on my immediate left estimating less than 500 ft horizontally and 200 ft below us on a southeasterly heading turning towards 16L.To be honest I was shocked at not only the controller putting an aircraft underneath us to runway 16L but I cannot believe [that] Aircraft Y was in the Class B airspace at his altitude and at our position to the runway.  Further and to put it bluntly it was a foolish and unsafe maneuver by the crew [of] Aircraft Y to fly underneath us at that altitude to maneuver for 16L.  Let alone accept a clearance to do so.Finally if we were spaced the same distance to the runways; why didn't we get 16L (we were coming off the Kipper 5) with Aircraft Y coming from the west 16R?  This sequencing made zero sense.Quite frankly the potential for a collision was high confirmed by the fact getting an RA that close to the FAF.  I called the TRACON Supervisor upon arrival and explained my concern.  He took my number and promised a call back after reviewing the incident.  I did not catch Aircraft Y's flight number.
B787 Captain reported an NMAC approaching the final approach fix at DEN.