Air carrier has TCASII RA. Responds.

Attributes
ACN	181849
Time
Date	199106
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bae
State Reference	WI
Altitude	msl bound lower : 10000 msl bound upper : 10500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute airway : zau
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 13000 flight time type : 1000
ASRS Report	181849
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
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 flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were alerted to a traffic conflict by a TCASII warning showing an intruder at our 11 O'clock position and 4 mi 100' below us. We were not successful in locating the intruder visly and then the intruder entered the range ring (which is at two mi) and we got the computer command to climb. As PIC I made a decision to climb 500' and then called ATC. He said an aircraft had 'just popped up at 9800'.' we showed he was at 10000' on the TCASII. I then got a visibility on the intruder at 1/2 mi. It was a single engine airplane heading ese. (We were heading east). I believe if we had not followed TCASII we would have (at the least) needed to do a violent maneuver in order to avoid the other aircraft. If we had not seen the other aircraft (and had not initiated a climb) it is very possible a mid-air would have occurred. My recommendation: that all large turbojet aircraft be required to have TCASII and all aircraft flying in controled airspace be required to have mode C. Also, all pilots should be encouraged to use and believe TCASII warnings.

Original NASA ASRS Text

Title: ACR HAS TCASII RA. RESPONDS.

Narrative: WE WERE ALERTED TO A TFC CONFLICT BY A TCASII WARNING SHOWING AN INTRUDER AT OUR 11 O'CLOCK POS AND 4 MI 100' BELOW US. WE WERE NOT SUCCESSFUL IN LOCATING THE INTRUDER VISLY AND THEN THE INTRUDER ENTERED THE RANGE RING (WHICH IS AT TWO MI) AND WE GOT THE COMPUTER COMMAND TO CLB. AS PIC I MADE A DECISION TO CLB 500' AND THEN CALLED ATC. HE SAID AN ACFT HAD 'JUST POPPED UP AT 9800'.' WE SHOWED HE WAS AT 10000' ON THE TCASII. I THEN GOT A VIS ON THE INTRUDER AT 1/2 MI. IT WAS A SINGLE ENG AIRPLANE HDG ESE. (WE WERE HDG E). I BELIEVE IF WE HAD NOT FOLLOWED TCASII WE WOULD HAVE (AT THE LEAST) NEEDED TO DO A VIOLENT MANEUVER IN ORDER TO AVOID THE OTHER ACFT. IF WE HAD NOT SEEN THE OTHER ACFT (AND HAD NOT INITIATED A CLB) IT IS VERY POSSIBLE A MID-AIR WOULD HAVE OCCURRED. MY RECOMMENDATION: THAT ALL LARGE TURBOJET ACFT BE REQUIRED TO HAVE TCASII AND ALL ACFT FLYING IN CTLED AIRSPACE BE REQUIRED TO HAVE MODE C. ALSO, ALL PLTS SHOULD BE ENCOURAGED TO USE AND BELIEVE TCASII WARNINGS.

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.