Air carrier X TCASII RA evasive action taken from ghost target.

Attributes
ACN	247013
Time
Date	199306
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : ord
State Reference	IL
Altitude	msl bound lower : 2600 msl bound upper : 2600
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	other personnel other
Qualification	controller : radar
ASRS Report	247013
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : undershoot non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X was 2 mi southwest of rekks OM (runway 4R). Cleared for the approach. The pilot said he was responding to an RA for traffic at 2400 ft. The only traffic in the area was the previous arrival 3 mi ahead and a departure 3 southeast of ord climbing out of 3500 ft. No other targets in the area. This seems to be yet another example of TCASII acting on a ghost target.

Original NASA ASRS Text

Title: ACR X TCASII RA EVASIVE ACTION TAKEN FROM GHOST TARGET.

Narrative: ACR X WAS 2 MI SW OF REKKS OM (RWY 4R). CLRED FOR THE APCH. THE PLT SAID HE WAS RESPONDING TO AN RA FOR TFC AT 2400 FT. THE ONLY TFC IN THE AREA WAS THE PREVIOUS ARR 3 MI AHEAD AND A DEP 3 SE OF ORD CLBING OUT OF 3500 FT. NO OTHER TARGETS IN THE AREA. THIS SEEMS TO BE YET ANOTHER EXAMPLE OF TCASII ACTING ON A GHOST TARGET.

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.