Narrative:

On dec/xx/91 on flight from dfw to cle, an irregularity on the departure climb out to 10000 ft occurred. Takeoff was using 35L. A heading of 090 degrees was established in the climb to intercept the dfw 067 degree radial. We were perhaps 15 mi north of the airport and 15 mi or better from blue ridge VOR crossing the buj approximately 230 degree radial (blue ridge III arrival) corridor at roughly 9600 ft when the TCASII TA sounded. I (first officer) was the PF and I glanced down but could not identify any conflict. At the same moment our engineer shouted we had traffic at 10-11 O'clock, closing fast! I looked up in that direction to see a pair of equal sized lights that appeared as 1 aircraft less than a mi, co-altitude, and closing. I pushed the nose forward to level off and checked my vsi for a TCASII resolution. The engineer said 'check your altitude.' I had either leveled off 300 ft early or he thought we were descending. The lights must have been an optical illusion because they separated and no further evasive action was warranted. We continued the climb to 10000 and the departure without further occurrence or notification from ATC but our hearts were in our mouths. Supplemental information from acn 196995: the traffic spotted turned out not to be traffic at all, but 2 aircraft a good distance from us that appeared to be a single closer aircraft due to the relative position of their landing lights, and the TCASII warning was for an unrelated aircraft that was passing behind us at 11000 ft MSL.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR LGT ALTDEV EXCURSION FROM CLRNC ALT IN RESPONSE TO TCASII TA.

Narrative: ON DEC/XX/91 ON FLT FROM DFW TO CLE, AN IRREGULARITY ON THE DEP CLB OUT TO 10000 FT OCCURRED. TKOF WAS USING 35L. A HDG OF 090 DEGS WAS ESTABLISHED IN THE CLB TO INTERCEPT THE DFW 067 DEG RADIAL. WE WERE PERHAPS 15 MI N OF THE ARPT AND 15 MI OR BETTER FROM BLUE RIDGE VOR XING THE BUJ APPROX 230 DEG RADIAL (BLUE RIDGE III ARR) CORRIDOR AT ROUGHLY 9600 FT WHEN THE TCASII TA SOUNDED. I (FO) WAS THE PF AND I GLANCED DOWN BUT COULD NOT IDENT ANY CONFLICT. AT THE SAME MOMENT OUR ENGINEER SHOUTED WE HAD TFC AT 10-11 O'CLOCK, CLOSING FAST! I LOOKED UP IN THAT DIRECTION TO SEE A PAIR OF EQUAL SIZED LIGHTS THAT APPEARED AS 1 ACFT LESS THAN A MI, CO-ALT, AND CLOSING. I PUSHED THE NOSE FORWARD TO LEVEL OFF AND CHKED MY VSI FOR A TCASII RESOLUTION. THE ENGINEER SAID 'CHK YOUR ALT.' I HAD EITHER LEVELED OFF 300 FT EARLY OR HE THOUGHT WE WERE DSNDING. THE LIGHTS MUST HAVE BEEN AN OPTICAL ILLUSION BECAUSE THEY SEPARATED AND NO FURTHER EVASIVE ACTION WAS WARRANTED. WE CONTINUED THE CLB TO 10000 AND THE DEP WITHOUT FURTHER OCCURRENCE OR NOTIFICATION FROM ATC BUT OUR HEARTS WERE IN OUR MOUTHS. SUPPLEMENTAL INFO FROM ACN 196995: THE TFC SPOTTED TURNED OUT NOT TO BE TFC AT ALL, BUT 2 ACFT A GOOD DISTANCE FROM US THAT APPEARED TO BE A SINGLE CLOSER ACFT DUE TO THE RELATIVE POS OF THEIR LNDG LIGHTS, AND THE TCASII WARNING WAS FOR AN UNRELATED ACFT THAT WAS PASSING BEHIND US AT 11000 FT MSL.

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.