Do-328 crew had TCASII RA's from phantom targets in ZID class a airspace.

Attributes
ACN	544327
Time
Date	200204
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zid.artcc
State Reference	IN
Altitude	msl single value : 23000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc tracon : hnl.tracon
Operator	common carrier : air carrier
Make Model Name	Do 328 TP (Turboprop)
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 3400
ASRS Report	544327
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued advisory controller : provided flight assist flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew other
Miss Distance	horizontal : 15000 vertical : 600
Supplementary
Problem Areas	Aircraft
Primary Problem	Ambiguous

Narrative:

We were at cruise with TCASII in the normal mode. There was no indication of traffic on the 25 NM range. Then at 2.5 NM the traffic appeared -400 ft AGL, then disappeared. Then moments later, traffic appeared 1400 ft AGL with an RA command to descend. I followed the descent command when another TA appeared -800 ft below. I stopped the descent -- both targets cleared. ATC informed us that their data didn't reflect any other aircraft in vicinity. Because of this, I wrote up the TCASII for maintenance.

Original NASA ASRS Text

Title: DO-328 CREW HAD TCASII RA'S FROM PHANTOM TARGETS IN ZID CLASS A AIRSPACE.

Narrative: WE WERE AT CRUISE WITH TCASII IN THE NORMAL MODE. THERE WAS NO INDICATION OF TFC ON THE 25 NM RANGE. THEN AT 2.5 NM THE TFC APPEARED -400 FT AGL, THEN DISAPPEARED. THEN MOMENTS LATER, TFC APPEARED 1400 FT AGL WITH AN RA COMMAND TO DSND. I FOLLOWED THE DSCNT COMMAND WHEN ANOTHER TA APPEARED -800 FT BELOW. I STOPPED THE DSCNT -- BOTH TARGETS CLRED. ATC INFORMED US THAT THEIR DATA DIDN'T REFLECT ANY OTHER ACFT IN VICINITY. BECAUSE OF THIS, I WROTE UP THE TCASII FOR MAINT.

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.