TCASII alert between air carrier a and uga B.

Attributes
ACN	280575
Time
Date	199408
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gbg
State Reference	IL
Altitude	msl bound lower : 4800 msl bound upper : 5500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	other : unknown
Flight Phase	climbout : intermediate altitude
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 1
ASRS Report	280575
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp pilot : commercial
Events
Anomaly	conflict : airborne less severe
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	vertical : 700
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

B727 inbound for visual approach, issued a 10 degree right turn and pilot discretionary descent to 3000 ft from 10000 ft. C172 sebound VFR climbing to 7500 ft was issued B727 and reported it in sight and agreed to maintain visual separation. B727 reported C172 not in sight and levelling at 5500 ft. The C172 was at 4800 ft. The B727 and C172 passed and were advised 'traffic no factor.' the B727 then resumed descent and advised they had followed TCASII instructions for an 'RA.' C172's visual separation standards and TCASII separation standards are different causing the RA.

Original NASA ASRS Text

Title: TCASII ALERT BTWN ACR A AND UGA B.

Narrative: B727 INBOUND FOR VISUAL APCH, ISSUED A 10 DEG R TURN AND PLT DISCRETIONARY DSCNT TO 3000 FT FROM 10000 FT. C172 SEBOUND VFR CLBING TO 7500 FT WAS ISSUED B727 AND RPTED IT IN SIGHT AND AGREED TO MAINTAIN VISUAL SEPARATION. B727 RPTED C172 NOT IN SIGHT AND LEVELLING AT 5500 FT. THE C172 WAS AT 4800 FT. THE B727 AND C172 PASSED AND WERE ADVISED 'TFC NO FACTOR.' THE B727 THEN RESUMED DSCNT AND ADVISED THEY HAD FOLLOWED TCASII INSTRUCTIONS FOR AN 'RA.' C172'S VISUAL SEPARATION STANDARDS AND TCASII SEPARATION STANDARDS ARE DIFFERENT CAUSING THE RA.

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.