Large transport has TCASII RA. ATC says no traffic.

Attributes
ACN	250402
Time
Date	199308
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mem
State Reference	TN
Altitude	msl bound lower : 7000 msl bound upper : 7600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mem tower : ind
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival star : star
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 200 flight time total : 9000 flight time type : 900
ASRS Report	250402
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 600
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

Awhile on gilmore arrival to memphis, we were leveling at assigned altitude of 7000 ft. A TCASII target suddenly appeared at -600 ft at 12 - 1 O'clock, less than 2 mi which caused an RA to immediately climb. The target passed under us and we leveled at 7600 ft, and then descended back to 7000 ft. Approach said they saw no targets that would cause our RA and we saw no aircraft. It was VFR but slightly hazy.

Original NASA ASRS Text

Title: LGT HAS TCASII RA. ATC SAYS NO TFC.

Narrative: AWHILE ON GILMORE ARR TO MEMPHIS, WE WERE LEVELING AT ASSIGNED ALT OF 7000 FT. A TCASII TARGET SUDDENLY APPEARED AT -600 FT AT 12 - 1 O'CLOCK, LESS THAN 2 MI WHICH CAUSED AN RA TO IMMEDIATELY CLB. THE TARGET PASSED UNDER US AND WE LEVELED AT 7600 FT, AND THEN DSNDED BACK TO 7000 FT. APCH SAID THEY SAW NO TARGETS THAT WOULD CAUSE OUR RA AND WE SAW NO ACFT. IT WAS VFR BUT SLIGHTLY HAZY.

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.