TCASII RA causes flight crew to perform an evasive action climb.

Attributes
ACN	266376
Time
Date	199403
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dfw
State Reference	TX
Altitude	msl bound lower : 11000 msl bound upper : 11300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 7500 flight time type : 150
ASRS Report	266376
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	vertical : 800
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

We were level at 11000 ft, 3 NM from refil on the sly 5 STAR into dfw. Dfw approach called traffic 1000 ft below us, 3 mi, passing from right to left. We told him no contact. TCASII showed a TA for traffic 1000 ft below us. TCASII then showed traffic less than 1 mi. TCASII told us to monitor vertical speed. TCASII then showed traffic 900 ft below us and climbing. We received an RA, TCASII told us to climb. We told ATC we were climbing due to TCASII alert. We climbed 300 ft. TCASII told us to monitor vertical speed. We leveled and TCASII told us clear of traffic. We told ATC we were descending back to 11000 ft. At 11000 ft we continued the STAR. ATC told us we did not conflict with higher traffic. TCASII is too sensitive for traffic separation of 1000 ft or less.

Original NASA ASRS Text

Title: TCASII RA CAUSES FLC TO PERFORM AN EVASIVE ACTION CLB.

Narrative: WE WERE LEVEL AT 11000 FT, 3 NM FROM REFIL ON THE SLY 5 STAR INTO DFW. DFW APCH CALLED TFC 1000 FT BELOW US, 3 MI, PASSING FROM R TO L. WE TOLD HIM NO CONTACT. TCASII SHOWED A TA FOR TFC 1000 FT BELOW US. TCASII THEN SHOWED TFC LESS THAN 1 MI. TCASII TOLD US TO MONITOR VERT SPD. TCASII THEN SHOWED TFC 900 FT BELOW US AND CLBING. WE RECEIVED AN RA, TCASII TOLD US TO CLB. WE TOLD ATC WE WERE CLBING DUE TO TCASII ALERT. WE CLBED 300 FT. TCASII TOLD US TO MONITOR VERT SPD. WE LEVELED AND TCASII TOLD US CLR OF TFC. WE TOLD ATC WE WERE DSNDING BACK TO 11000 FT. AT 11000 FT WE CONTINUED THE STAR. ATC TOLD US WE DID NOT CONFLICT WITH HIGHER TFC. TCASII IS TOO SENSITIVE FOR TFC SEPARATION OF 1000 FT OR LESS.

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.