Narrative:

We first received an amber TA at 2 O'clock position, visually saw lights at same position but were unable to define exact distance and altitude. Seconds later an RA was issued (climb). Disconnected autoplt and began climb (300 ft). Advisory disappeared after we notified ATC and we returned to FL310. ATC stated that there was no observed traffic in our vicinity, but added that it may have been military.

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Original NASA ASRS Text

Title: FLC OF A DC9-40 CLBED IN RESPONSE TO A TCASII RA DURING CRUISE. ARTCC RADAR CTLR SAID THAT THEY DID NOT HAVE ANY TARGET THAT WOULD HAVE CAUSED THE TCASII WARNING. THEY SUGGESTED THAT IT COULD HAVE BEEN A MIL ACFT.

Narrative: WE FIRST RECEIVED AN AMBER TA AT 2 O'CLOCK POS, VISUALLY SAW LIGHTS AT SAME POS BUT WERE UNABLE TO DEFINE EXACT DISTANCE AND ALT. SECONDS LATER AN RA WAS ISSUED (CLB). DISCONNECTED AUTOPLT AND BEGAN CLB (300 FT). ADVISORY DISAPPEARED AFTER WE NOTIFIED ATC AND WE RETURNED TO FL310. ATC STATED THAT THERE WAS NO OBSERVED TFC IN OUR VICINITY, BUT ADDED THAT IT MAY HAVE BEEN MIL.

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.