An air carrier crew on approach to den runway 16L had a near miss and TCAS RA with an air carrier ai...

Narrative:

On approach to runway 16L descending just prior to kikme intersection an airbus overshot the 16R localizer and flew what appeared to be less than 200 ft directly below our aircraft. Tower on frequency 120.8 did not call the traffic. We received a split last second RA and then it cleared. While it cleared I saw the airbus banking away from us in a descent. This is the closest I have ever come to a mid air collision in my entire career!I am still trying to determine how the airbus got so close so fast. At this point I have to assume that they were at a very aggressive intercept angle. The whole time our aircraft was on the localizer and glideslope with the autopilot on and the needles were perfectly aligned. We were in a stable descent on the glideslope well before seeing the airbus. The flight landed without further incident. The threats were the airbus flying underneath our aircraft. ATC not calling out either the airbus or the other airliner to our left until after we told them what had happened. I think ATC should have warned us about the airbus so we could have taken action before the TCAS gave us the TA/RA.

Original NASA ASRS Text

Title: An air carrier crew on approach to DEN Runway 16L had a near miss and TCAS RA with an air carrier aircraft which overshot Runway 16R with no warning or comment from ATC until after the encounter.

Narrative: On approach to Runway 16L descending just prior to KIKME Intersection an Airbus overshot the 16R localizer and flew what appeared to be less than 200 FT directly below our aircraft. Tower on frequency 120.8 did not call the traffic. We received a split last second RA and then it cleared. While it cleared I saw the Airbus banking away from us in a descent. This is the closest I have ever come to a mid air collision in my entire career!I am still trying to determine how the Airbus got so close so fast. At this point I have to assume that they were at a very aggressive intercept angle. The whole time our aircraft was on the localizer and glideslope with the autopilot on and the needles were perfectly aligned. We were in a stable descent on the glideslope well before seeing the Airbus. The flight landed without further incident. The threats were the Airbus flying underneath our aircraft. ATC not calling out either the Airbus or the other airliner to our left until after we told them what had happened. I think ATC should have warned us about the Airbus so we could have taken action before the TCAS gave us the TA/RA.

Data retrieved from NASA's ASRS site as of July 2013 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	1118239
Time
Date	201309
Local Time Of Day	0001-0600
Place
Locale Reference	D01.TRACON
State Reference	CO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Medium Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict NMAC Deviation - Procedural Published Material / Policy
Miss Distance	Horizontal 0 Vertical 100

An air carrier crew on approach to den runway 16L had a near miss and TCAS RA with an air carrier aircraft which overshot runway 16R with no warning or comment from ATC until after the encounter.