Narrative:

While on a scheduled airline flight, we had just leveled off at our assigned altitude of 13000 ft. This was approximately 1000 ft above the tops of a broken layer of cumulus clouds when center advised us of traffic at 12 O'clock, indicating 12500 ft, unverified. We saw the traffic who was also on TCASII about 3 NM. We observed this aircraft maneuver above and below our altitude approximately 500 ft. As this aircraft passed in front of us from left to right, we observed that it was moving at a high rate of speed and tried to ascertain its make when my first officer called out other traffic at 10 O'clock and closing from below. I saw this aircraft, an A-10 warthog, less than 1/2 mi from us and climbing from below toward our aircraft. I disconnected the autoplt and began an climb turn for avoidance when he passed below us at approximately 200 ft. We had been able to climb only 100 ft and turn 10 degrees due to the short reaction time. The total time this aircraft was in sight was at most 5 seconds. In informed ZKC that we had a near miss with a A-10 that was not the aircraft he had called as traffic. We were informed that the only traffic he saw was the one issued to us. We also did not see the second aircraft on our TCASII. We believe that the second aircraft was not operating his transponder. We believe that if military aircraft are operating as a flight of more than one ship, they should be in some proximity to one another. These aircraft were separated by 2 plus NM. At that distance we would have seen both of them on TCASII had both of them been operating their xponders. TCASII is useless if both aircraft are not squawking. Also if these aircraft are going to maneuver that close to the clouds while trying to get on top, they should have the appropriate clearance to do so. I hope that this was a change encounter and we were not being purposely targeted for practice by the second ship. I have had that happen on numerous occasions in the distant past by another unit.

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Original NASA ASRS Text

Title: NMAC BTWN AN MDT IN CRUISE AND A CLBING FIGHTER.

Narrative: WHILE ON A SCHEDULED AIRLINE FLT, WE HAD JUST LEVELED OFF AT OUR ASSIGNED ALT OF 13000 FT. THIS WAS APPROX 1000 FT ABOVE THE TOPS OF A BROKEN LAYER OF CUMULUS CLOUDS WHEN CTR ADVISED US OF TFC AT 12 O'CLOCK, INDICATING 12500 FT, UNVERIFIED. WE SAW THE TFC WHO WAS ALSO ON TCASII ABOUT 3 NM. WE OBSERVED THIS ACFT MANEUVER ABOVE AND BELOW OUR ALT APPROX 500 FT. AS THIS ACFT PASSED IN FRONT OF US FROM L TO R, WE OBSERVED THAT IT WAS MOVING AT A HIGH RATE OF SPD AND TRIED TO ASCERTAIN ITS MAKE WHEN MY FO CALLED OUT OTHER TFC AT 10 O'CLOCK AND CLOSING FROM BELOW. I SAW THIS ACFT, AN A-10 WARTHOG, LESS THAN 1/2 MI FROM US AND CLBING FROM BELOW TOWARD OUR ACFT. I DISCONNECTED THE AUTOPLT AND BEGAN AN CLB TURN FOR AVOIDANCE WHEN HE PASSED BELOW US AT APPROX 200 FT. WE HAD BEEN ABLE TO CLB ONLY 100 FT AND TURN 10 DEGS DUE TO THE SHORT REACTION TIME. THE TOTAL TIME THIS ACFT WAS IN SIGHT WAS AT MOST 5 SECONDS. IN INFORMED ZKC THAT WE HAD A NEAR MISS WITH A A-10 THAT WAS NOT THE ACFT HE HAD CALLED AS TFC. WE WERE INFORMED THAT THE ONLY TFC HE SAW WAS THE ONE ISSUED TO US. WE ALSO DID NOT SEE THE SECOND ACFT ON OUR TCASII. WE BELIEVE THAT THE SECOND ACFT WAS NOT OPERATING HIS XPONDER. WE BELIEVE THAT IF MIL ACFT ARE OPERATING AS A FLT OF MORE THAN ONE SHIP, THEY SHOULD BE IN SOME PROX TO ONE ANOTHER. THESE ACFT WERE SEPARATED BY 2 PLUS NM. AT THAT DISTANCE WE WOULD HAVE SEEN BOTH OF THEM ON TCASII HAD BOTH OF THEM BEEN OPERATING THEIR XPONDERS. TCASII IS USELESS IF BOTH ACFT ARE NOT SQUAWKING. ALSO IF THESE ACFT ARE GOING TO MANEUVER THAT CLOSE TO THE CLOUDS WHILE TRYING TO GET ON TOP, THEY SHOULD HAVE THE APPROPRIATE CLRNC TO DO SO. I HOPE THAT THIS WAS A CHANGE ENCOUNTER AND WE WERE NOT BEING PURPOSELY TARGETED FOR PRACTICE BY THE SECOND SHIP. I HAVE HAD THAT HAPPEN ON NUMEROUS OCCASIONS IN THE DISTANT PAST BY ANOTHER UNIT.

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.