Narrative:

On an IFR flight from cos to dia, cos departure called traffic at 12 O'clock, our altitude. We spotted him on TCASII at about 7-8 mi. I saw a plane at 11 O'clock and the first officer spotted another plane at 12 O'clock. The controller soon asked us if we wanted lower, but the 12 O'clock traffic appeared to be heading away to the east. At 6 mi, I realized that the 2 planes were T34's and remembered that there was a group that did dogfights out of centennial airport and gave people rides for a fee. I asked for higher as I did not wish to be between them and the ground. As we were then cleared to 13000 ft, the target aircraft indicated a climb to 12200 ft on our TCASII. I canceled the climb. The lead T34 then turned directly at us. We received a TCASII RA, followed immediately by an RA to descend. We followed the TCASII descend directive. I notified ATC. I observed the lead aircraft cross in front of us to the west. TCASII indicated 200 ft above us. The first officer noted the chase aircraft, in pursuit, pass over our aircraft at about 200 ft above us. The chase aircraft did not have its transponder on, so the TCASII could not help us with him. ATC did not see him either. It was apparent that these pilots were more concerned with the 'game' than the rules of see and be seen. ATC did not know they were doing what they were doing, so they could not warn us. I feel a NOTAM and ATC notification should have been issued.

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Original NASA ASRS Text

Title: FLC OF LGT HAS NMAC WITH 2 T34 ACFT WHICH ARE DOG FIGHTING. TCASII GAVE THE INDICATION OF THEIR MOVEMENT SO FLC COULD AVOID CONFLICT.

Narrative: ON AN IFR FLT FROM COS TO DIA, COS DEP CALLED TFC AT 12 O'CLOCK, OUR ALT. WE SPOTTED HIM ON TCASII AT ABOUT 7-8 MI. I SAW A PLANE AT 11 O'CLOCK AND THE FO SPOTTED ANOTHER PLANE AT 12 O'CLOCK. THE CTLR SOON ASKED US IF WE WANTED LOWER, BUT THE 12 O'CLOCK TFC APPEARED TO BE HDG AWAY TO THE E. AT 6 MI, I REALIZED THAT THE 2 PLANES WERE T34'S AND REMEMBERED THAT THERE WAS A GROUP THAT DID DOGFIGHTS OUT OF CENTENNIAL ARPT AND GAVE PEOPLE RIDES FOR A FEE. I ASKED FOR HIGHER AS I DID NOT WISH TO BE BTWN THEM AND THE GND. AS WE WERE THEN CLRED TO 13000 FT, THE TARGET ACFT INDICATED A CLB TO 12200 FT ON OUR TCASII. I CANCELED THE CLB. THE LEAD T34 THEN TURNED DIRECTLY AT US. WE RECEIVED A TCASII RA, FOLLOWED IMMEDIATELY BY AN RA TO DSND. WE FOLLOWED THE TCASII DSND DIRECTIVE. I NOTIFIED ATC. I OBSERVED THE LEAD ACFT CROSS IN FRONT OF US TO THE W. TCASII INDICATED 200 FT ABOVE US. THE FO NOTED THE CHASE ACFT, IN PURSUIT, PASS OVER OUR ACFT AT ABOUT 200 FT ABOVE US. THE CHASE ACFT DID NOT HAVE ITS XPONDER ON, SO THE TCASII COULD NOT HELP US WITH HIM. ATC DID NOT SEE HIM EITHER. IT WAS APPARENT THAT THESE PLTS WERE MORE CONCERNED WITH THE 'GAME' THAN THE RULES OF SEE AND BE SEEN. ATC DID NOT KNOW THEY WERE DOING WHAT THEY WERE DOING, SO THEY COULD NOT WARN US. I FEEL A NOTAM AND ATC NOTIFICATION SHOULD HAVE BEEN ISSUED.

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.