B737-300 TCAS warns of traffic with aircraft on short final and flight crew executes G0-around.

Attributes
ACN	740447
Time
Date	200705
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : abq.airport
State Reference	NM
Altitude	msl single value : 700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : abq.tower
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 08
Flight Phase	descent : approach landing : go around ground : maintenance
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 228 flight time type : 13500
ASRS Report	740447
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 234 flight time type : 1800
ASRS Report	740450
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : executed go around
Supplementary
Problem Areas	Aircraft Environmental Factor
Primary Problem	Ambiguous

Narrative:

The first officer was flying; I was pm. On final approach into abq on runway 8 at 700 ft we received a TA. I looked out the window and questioned the tower about any helicopters in the area since I could not imagine an aircraft that close to us on the approach to final. They said there was no traffic reported or observed. We continued on the GS and localizer and I scanned the horizon for any aircraft. We received a TA/RA at approximately 300 ft and saw the bottom half of the ivsi go red and heard monitor vertical speed. We did a normal go around and returned to the localizer and GS and received another TA; this time at 300 ft but no TA/RA; so we landed uneventfully. I called the tower and spoke with the supervisor. He advised that this had happened to another carrier a few weeks ago and they had gone around also. They think there is something on the final that is propagating a false signal but have so far been unable to determine its source. Find the anomalous propagation.

Original NASA ASRS Text

Title: B737-300 TCAS WARNS OF TRAFFIC WITH ACFT ON SHORT FINAL AND FLT CREW EXECUTES G0-AROUND.

Narrative: THE FO WAS FLYING; I WAS PM. ON FINAL APCH INTO ABQ ON RWY 8 AT 700 FT WE RECEIVED A TA. I LOOKED OUT THE WINDOW AND QUESTIONED THE TWR ABOUT ANY HELIS IN THE AREA SINCE I COULD NOT IMAGINE AN ACFT THAT CLOSE TO US ON THE APCH TO FINAL. THEY SAID THERE WAS NO TFC RPTED OR OBSERVED. WE CONTINUED ON THE GS AND LOC AND I SCANNED THE HORIZON FOR ANY ACFT. WE RECEIVED A TA/RA AT APPROX 300 FT AND SAW THE BOTTOM HALF OF THE IVSI GO RED AND HEARD MONITOR VERT SPD. WE DID A NORMAL GAR AND RETURNED TO THE LOC AND GS AND RECEIVED ANOTHER TA; THIS TIME AT 300 FT BUT NO TA/RA; SO WE LANDED UNEVENTFULLY. I CALLED THE TWR AND SPOKE WITH THE SUPVR. HE ADVISED THAT THIS HAD HAPPENED TO ANOTHER CARRIER A FEW WKS AGO AND THEY HAD GONE AROUND ALSO. THEY THINK THERE IS SOMETHING ON THE FINAL THAT IS PROPAGATING A FALSE SIGNAL BUT HAVE SO FAR BEEN UNABLE TO DETERMINE ITS SOURCE. FIND THE ANOMALOUS PROPAGATION.

Data retrieved from NASA's ASRS site as of January 2009 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.