Medium large transport has TCASII TA then RA.

Attributes
ACN	276597
Time
Date	199407
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bld airport : las
State Reference	NV
Altitude	msl bound lower : 11000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival other enroute airway : las
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 230 flight time total : 21000 flight time type : 3700
ASRS Report	276597
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Flight was within 20 NM of bld VOR inbound las on the creso 3 at 11000 ft. ATC called traffic at 5 mi, 12 O'clock, 10500 ft, unconfirmed (opposite direction). I was not able to see the traffic. TCASII target then appeared on screen at 4 mi, 400 ft below our aircraft (amber indication). At 3 mi TCASII symbol changed to red and altitude separation of target decreased to 300 ft below. ATC again advised traffic at 3 mi and 12 O'clock, but it was not sighted, captain was flying and elected to turn right 90 degrees (no TCASII RA when turn started). I advised las approach of our turn and TCASII RA advising climb started at about the same time. Captain advised that he saw a low wing single engine aircraft close by off the left wing, opposite direction at less than 200 ft vertical separation and less than 500 ft away. We gained only a few hundred ft when the RA stopped and we advised ATC that we were returning to assigned route and altitude. I saw the traffic only briefly and agree with the miss distances described.

Original NASA ASRS Text

Title: MLG HAS TCASII TA THEN RA.

Narrative: FLT WAS WITHIN 20 NM OF BLD VOR INBOUND LAS ON THE CRESO 3 AT 11000 FT. ATC CALLED TFC AT 5 MI, 12 O'CLOCK, 10500 FT, UNCONFIRMED (OPPOSITE DIRECTION). I WAS NOT ABLE TO SEE THE TFC. TCASII TARGET THEN APPEARED ON SCREEN AT 4 MI, 400 FT BELOW OUR ACFT (AMBER INDICATION). AT 3 MI TCASII SYMBOL CHANGED TO RED AND ALT SEPARATION OF TARGET DECREASED TO 300 FT BELOW. ATC AGAIN ADVISED TFC AT 3 MI AND 12 O'CLOCK, BUT IT WAS NOT SIGHTED, CAPT WAS FLYING AND ELECTED TO TURN R 90 DEGS (NO TCASII RA WHEN TURN STARTED). I ADVISED LAS APCH OF OUR TURN AND TCASII RA ADVISING CLB STARTED AT ABOUT THE SAME TIME. CAPT ADVISED THAT HE SAW A LOW WING SINGLE ENG ACFT CLOSE BY OFF THE L WING, OPPOSITE DIRECTION AT LESS THAN 200 FT VERT SEPARATION AND LESS THAN 500 FT AWAY. WE GAINED ONLY A FEW HUNDRED FT WHEN THE RA STOPPED AND WE ADVISED ATC THAT WE WERE RETURNING TO ASSIGNED RTE AND ALT. I SAW THE TFC ONLY BRIEFLY AND AGREE WITH THE MISS DISTANCES DESCRIBED.

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.