TCASII alert to air carrier a for proximity of air carrier B.

Attributes
ACN	280295
Time
Date	199408
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : int
State Reference	NC
Altitude	msl bound lower : 5000 msl bound upper : 6000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : gso tower : sba
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 5 controller non radar : 2 controller radar : 2
ASRS Report	280295
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action flight crew : returned to intended course or assigned course none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 6000 vertical : 1000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Air carrier a B737/right departed runway 23 at gso. Air carrier B B737/right 20 NM northwest of gso descending for landing gso. Air carrier a turned right to heading 310 degrees to maintain 5000 ft. Air carrier B descended to 6000 ft heading 050 degrees downwind. Traffic issued to both aircraft. When aircraft about 1 mi apart I observed air carrier a descending to 4500 ft. Air carrier a then called advising he was responding to an RA. Aircraft passed and air carrier a advised he was returning to assigned altitude 5000 ft. I realize the purpose and importance of TCASII, however utilizing this technology in the terminal environment in RA mode represents hazards since aircraft are normally very close together during arrival and departure phases of flight. It also makes me feel kind of worthless after assuring required separation and issuing traffic that an aircraft would still feel the need to deviate from ATC instructions.

Original NASA ASRS Text

Title: TCASII ALERT TO ACR A FOR PROX OF ACR B.

Narrative: ACR A B737/R DEPARTED RWY 23 AT GSO. ACR B B737/R 20 NM NW OF GSO DSNDING FOR LNDG GSO. ACR A TURNED R TO HDG 310 DEGS TO MAINTAIN 5000 FT. ACR B DSNDED TO 6000 FT HDG 050 DEGS DOWNWIND. TFC ISSUED TO BOTH ACFT. WHEN ACFT ABOUT 1 MI APART I OBSERVED ACR A DSNDING TO 4500 FT. ACR A THEN CALLED ADVISING HE WAS RESPONDING TO AN RA. ACFT PASSED AND ACR A ADVISED HE WAS RETURNING TO ASSIGNED ALT 5000 FT. I REALIZE THE PURPOSE AND IMPORTANCE OF TCASII, HOWEVER UTILIZING THIS TECHNOLOGY IN THE TERMINAL ENVIRONMENT IN RA MODE REPRESENTS HAZARDS SINCE ACFT ARE NORMALLY VERY CLOSE TOGETHER DURING ARR AND DEP PHASES OF FLT. IT ALSO MAKES ME FEEL KIND OF WORTHLESS AFTER ASSURING REQUIRED SEPARATION AND ISSUING TFC THAT AN ACFT WOULD STILL FEEL THE NEED TO DEVIATE FROM ATC INSTRUCTIONS.

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.