An medium large transport air carrier climbed in response to a TCASII alert.

Attributes
ACN	218283
Time
Date	199208
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : scy airport : dfw
State Reference	TX
Altitude	msl bound lower : 11000 msl bound upper : 11400
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	departure other departure sid : sid
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 7000 flight time type : 800
ASRS Report	218283
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
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 flight crew : overcame equipment problem flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	vertical : 1400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

At 11000 ft level 250 KTS. Approach reported traffic to us. We were in and out of cumulus clouds. TCASII showed a yellow target 1200 ft below us climbing, at close proximity. Then 'monitor vertical speed.' ivsi indicated 2000 FPM climb. First officer was flying and turned off autoplt, began a climb, got to 11400 ft when TCASII indicated clear of conflict. We returned to 11000 ft and notified ATC of altitude deviation, reason and correction. Never saw traffic, and don't believe either aircraft were in danger of a near miss. Other traffic was climbing to 10000 ft and computer read it as a collision course.

Original NASA ASRS Text

Title: AN MLG ACR CLBED IN RESPONSE TO A TCASII ALERT.

Narrative: AT 11000 FT LEVEL 250 KTS. APCH RPTED TFC TO US. WE WERE IN AND OUT OF CUMULUS CLOUDS. TCASII SHOWED A YELLOW TARGET 1200 FT BELOW US CLBING, AT CLOSE PROX. THEN 'MONITOR VERT SPD.' IVSI INDICATED 2000 FPM CLB. FO WAS FLYING AND TURNED OFF AUTOPLT, BEGAN A CLB, GOT TO 11400 FT WHEN TCASII INDICATED CLR OF CONFLICT. WE RETURNED TO 11000 FT AND NOTIFIED ATC OF ALTDEV, REASON AND CORRECTION. NEVER SAW TFC, AND DON'T BELIEVE EITHER ACFT WERE IN DANGER OF A NEAR MISS. OTHER TFC WAS CLBING TO 10000 FT AND COMPUTER READ IT AS A COLLISION COURSE.

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.