Air carrier avoids VFR small aircraft by 200 ft as the result of a TCASII RA.

Attributes
ACN	447316
Time
Date	199908
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	intersection : garro
State Reference	RI
Altitude	msl bound lower : 10800 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : green.one
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zbw.artcc
Operator	general aviation : personal
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 13000 flight time type : 1825
ASRS Report	447316
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 4000 flight time type : 1000
ASRS Report	447765
Events
Anomaly	conflict : airborne critical conflict : nmac other anomaly other other spatial deviation
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Descending on the green one arrival, we were cleared to cross the garrd intersection at 11000 ft. Approaching 11000 ft we received a TCASII TA followed immediately by an RA to monitor vertical speed and descend. We descended to about 10800 ft when we saw the traffic at 12 O'clock position about 200 ft above us as we passed under him. We advised ATC of our actions. Center said the traffic was VFR and they were not talking to him. Aircraft was a single engine, low wing. I feel we would not have seen the traffic if we had not gotten the TCASII warning.

Original NASA ASRS Text

Title: ACR AVOIDS VFR SMALL ACFT BY 200 FT AS THE RESULT OF A TCASII RA.

Narrative: DSNDING ON THE GREEN ONE ARR, WE WERE CLRED TO CROSS THE GARRD INTXN AT 11000 FT. APCHING 11000 FT WE RECEIVED A TCASII TA FOLLOWED IMMEDIATELY BY AN RA TO MONITOR VERT SPD AND DSND. WE DSNDED TO ABOUT 10800 FT WHEN WE SAW THE TFC AT 12 O'CLOCK POS ABOUT 200 FT ABOVE US AS WE PASSED UNDER HIM. WE ADVISED ATC OF OUR ACTIONS. CTR SAID THE TFC WAS VFR AND THEY WERE NOT TALKING TO HIM. ACFT WAS A SINGLE ENG, LOW WING. I FEEL WE WOULD NOT HAVE SEEN THE TFC IF WE HAD NOT GOTTEN THE TCASII WARNING.

Data retrieved from NASA's ASRS site as of July 2007 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.