BE40 on IFR descent with D10; experienced TCAS RA with light aircraft; no traffic issued by ATC.

Attributes
ACN	688495
Time
Date	200602
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : d10.tracon
State Reference	TX
Altitude	msl bound lower : 5000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : d10.tracon
Operator	general aviation : corporate
Make Model Name	Beechjet 400
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : d10.tracon
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 7000 flight time type : 3000
ASRS Report	688495
Person 2
Affiliation	other
Function	oversight : pic
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 500 vertical : 500
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Intra Facility Coordination Failure

Narrative:

While being vectored by dallas approach we received a traffic alert from our TCAS. I noticed a target moving toward us at our same altitude. About that time we received an RA from our TCAS commanding a descent which we did. The aircraft appeared to be a C172 or some sort of light aircraft; which passed directly over us at about 500 ft. We advised ATC of the RA and told them we had descended. ATC controller said the guy sitting next to him was controling the other aircraft and that its altimeter had spiked and that's what gave us the RA. I think if we had not descended this would have been a near miss possibly a midair collision.

Original NASA ASRS Text

Title: BE40 ON IFR DSCNT WITH D10; EXPERIENCED TCAS RA WITH LIGHT ACFT; NO TFC ISSUED BY ATC.

Narrative: WHILE BEING VECTORED BY DALLAS APCH WE RECEIVED A TFC ALERT FROM OUR TCAS. I NOTICED A TARGET MOVING TOWARD US AT OUR SAME ALT. ABOUT THAT TIME WE RECEIVED AN RA FROM OUR TCAS COMMANDING A DSCNT WHICH WE DID. THE ACFT APPEARED TO BE A C172 OR SOME SORT OF LIGHT ACFT; WHICH PASSED DIRECTLY OVER US AT ABOUT 500 FT. WE ADVISED ATC OF THE RA AND TOLD THEM WE HAD DSNDED. ATC CTLR SAID THE GUY SITTING NEXT TO HIM WAS CTLING THE OTHER ACFT AND THAT ITS ALTIMETER HAD SPIKED AND THAT'S WHAT GAVE US THE RA. I THINK IF WE HAD NOT DSNDED THIS WOULD HAVE BEEN A NEAR MISS POSSIBLY A MIDAIR COLLISION.

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.