TCASII prevents a conflict or collision.

Attributes
ACN	256085
Time
Date	199311
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pvd
State Reference	RI
Altitude	msl bound lower : 4100 msl bound upper : 4600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pvd
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10000 flight time type : 7000
ASRS Report	256085
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical conflict : airborne less severe non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Climbing out of providence under departure control, runway heading to 5000 ft. Received 'traffic, traffic' alert from TCASII and noted traffic at 12 O'clock approximately 10 mi on 20 mi scope. Altitude separation was plus 17. I advised first officer (flying) to watch out for traffic, as we were under a thin overcast, and selected 10 mi scope. First officer reduced climb rate. As traffic closed to about 3 mi, TCASII gave 'monitor vertical speed,' and we leveled at 4000 ft. Overcast prevented us from seeing traffic as it passed overhead. I advised ATC of our level off for TCASII and traffic. He told us he had traffic at our 6 O'clock position at 4600 ft (6 mi) and had seen him (traffic) at our 11-12 O'clock position. ATC did not advise us, for some reason. (This after receiving 'clear of conflict' and leveling at 5000 ft.) our TCASII failed shortly after this event. I'm very happy it worked when it did! Traffic was apparently VFR in VMC conditions just above a thin overcast/broken cloud layer at that area.

Original NASA ASRS Text

Title: TCASII PREVENTS A CONFLICT OR COLLISION.

Narrative: CLBING OUT OF PROVIDENCE UNDER DEP CTL, RWY HDG TO 5000 FT. RECEIVED 'TFC, TFC' ALERT FROM TCASII AND NOTED TFC AT 12 O'CLOCK APPROX 10 MI ON 20 MI SCOPE. ALT SEPARATION WAS PLUS 17. I ADVISED FO (FLYING) TO WATCH OUT FOR TFC, AS WE WERE UNDER A THIN OVCST, AND SELECTED 10 MI SCOPE. FO REDUCED CLB RATE. AS TFC CLOSED TO ABOUT 3 MI, TCASII GAVE 'MONITOR VERT SPD,' AND WE LEVELED AT 4000 FT. OVCST PREVENTED US FROM SEEING TFC AS IT PASSED OVERHEAD. I ADVISED ATC OF OUR LEVEL OFF FOR TCASII AND TFC. HE TOLD US HE HAD TFC AT OUR 6 O'CLOCK POS AT 4600 FT (6 MI) AND HAD SEEN HIM (TFC) AT OUR 11-12 O'CLOCK POS. ATC DID NOT ADVISE US, FOR SOME REASON. (THIS AFTER RECEIVING 'CLR OF CONFLICT' AND LEVELING AT 5000 FT.) OUR TCASII FAILED SHORTLY AFTER THIS EVENT. I'M VERY HAPPY IT WORKED WHEN IT DID! TFC WAS APPARENTLY VFR IN VMC CONDITIONS JUST ABOVE A THIN OVCST/BROKEN CLOUD LAYER AT THAT AREA.

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.