Cpr X false TCASII RA on short final executed a go around.

Attributes
ACN	244910
Time
Date	199306
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pwk
State Reference	IL
Altitude	agl bound lower : 400 agl bound upper : 400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : pwk
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
Experience	controller military : 4 controller non radar : 2 controller radar : 14
ASRS Report	244910
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Cpr X was on short final for runway 34 when he advised he was going around. I issued go around instructions and the pilot told me his go around was due to a TCASII RA on an aircraft 300 ft below him. There were no aircraft within 2 mi of cpr X. Furthermore, 300 ft below him would have been nearly at ground level. I have no idea why TCASII issued cpr Y an RA. I will not trust TCASII until the bugs are worked out.

Original NASA ASRS Text

Title: CPR X FALSE TCASII RA ON SHORT FINAL EXECUTED A GAR.

Narrative: CPR X WAS ON SHORT FINAL FOR RWY 34 WHEN HE ADVISED HE WAS GOING AROUND. I ISSUED GAR INSTRUCTIONS AND THE PLT TOLD ME HIS GAR WAS DUE TO A TCASII RA ON AN ACFT 300 FT BELOW HIM. THERE WERE NO ACFT WITHIN 2 MI OF CPR X. FURTHERMORE, 300 FT BELOW HIM WOULD HAVE BEEN NEARLY AT GND LEVEL. I HAVE NO IDEA WHY TCASII ISSUED CPR Y AN RA. I WILL NOT TRUST TCASII UNTIL THE BUGS ARE WORKED OUT.

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.