Narrative:

While cruising at FL350, a target was observed on the outer edge of the TCASII screen at approximately 11:30 O'clock to my position. That was followed shortly by a TA. The target was closing and was 200 ft below, then I received an RA to descend and turn left, which I did. The target was still closing and showing 100 ft low then same altitude. Target passed off the right at approximately 1 mi or less as observed on TCASII. I leveled off at FL337 and climbed back to FL350. I advised ATC of the RA and the controller advised that he had nothing in our vicinity except an aircraft at FL260, which we could see. I never made a visual contact with the target that caused the RA other than on TCASII. Also, I never received a 'clear of conflict' advisory from TCASII. The target just disappeared to the right rear of our position on the TCASII screen.

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Original NASA ASRS Text

Title: DC9 CREW HAD A TCASII RA IN ZID CLASS A AIRSPACE.

Narrative: WHILE CRUISING AT FL350, A TARGET WAS OBSERVED ON THE OUTER EDGE OF THE TCASII SCREEN AT APPROX 11:30 O'CLOCK TO MY POS. THAT WAS FOLLOWED SHORTLY BY A TA. THE TARGET WAS CLOSING AND WAS 200 FT BELOW, THEN I RECEIVED AN RA TO DSND AND TURN L, WHICH I DID. THE TARGET WAS STILL CLOSING AND SHOWING 100 FT LOW THEN SAME ALT. TARGET PASSED OFF THE R AT APPROX 1 MI OR LESS AS OBSERVED ON TCASII. I LEVELED OFF AT FL337 AND CLBED BACK TO FL350. I ADVISED ATC OF THE RA AND THE CTLR ADVISED THAT HE HAD NOTHING IN OUR VICINITY EXCEPT AN ACFT AT FL260, WHICH WE COULD SEE. I NEVER MADE A VISUAL CONTACT WITH THE TARGET THAT CAUSED THE RA OTHER THAN ON TCASII. ALSO, I NEVER RECEIVED A 'CLR OF CONFLICT' ADVISORY FROM TCASII. THE TARGET JUST DISAPPEARED TO THE R REAR OF OUR POS ON THE TCASII SCREEN.

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.