Air carrier descending has TCASII TA on traffic advised of by ATC. RA received, climb.

Attributes
ACN	208355
Time
Date	199204
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : phx
State Reference	AZ
Altitude	msl bound lower : 11000 msl bound upper : 12300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute airway : zab
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : flight engineer pilot : instrument pilot : atp
Experience	flight time last 90 days : 100 flight time total : 20000
ASRS Report	208355
Person 2
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : atp pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 125 flight time total : 1750 flight time type : 125
ASRS Report	208366
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Followed TCASII instruction to climb when descending to 12000 ft. ZAB called out traffic at 11000 level in front of us on the phx arrival. At 12600 ft the TCASII gave us a TA 'traffic' 1600 below us. We continued descending to 12000, but at about 12300 TCASII commanded 'climb' which we did. When the RA cleared we resumed descent to 12000 and had another TA traffic on the aircraft below us. Apparently the TCASII was activated by sink rate, not altitude intrusion.

Original NASA ASRS Text

Title: ACR DSNDING HAS TCASII TA ON TFC ADVISED OF BY ATC. RA RECEIVED, CLB.

Narrative: FOLLOWED TCASII INSTRUCTION TO CLB WHEN DSNDING TO 12000 FT. ZAB CALLED OUT TFC AT 11000 LEVEL IN FRONT OF US ON THE PHX ARR. AT 12600 FT THE TCASII GAVE US A TA 'TFC' 1600 BELOW US. WE CONTINUED DSNDING TO 12000, BUT AT ABOUT 12300 TCASII COMMANDED 'CLB' WHICH WE DID. WHEN THE RA CLRED WE RESUMED DSCNT TO 12000 AND HAD ANOTHER TA TFC ON THE ACFT BELOW US. APPARENTLY THE TCASII WAS ACTIVATED BY SINK RATE, NOT ALT INTRUSION.

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.