LGT ON STAR HAD NMAC WITH SMA INSIDE TCA BOUNDARIES.

Narrative

ON A STAR (BOIDS 9) WE WERE VECTORED TO INTERCEPT A HDG AND TO MAINTAIN 5000'. APCH GAVE US 3 BOGEYS; ONE AT 12 O'CLOCK; ONE AT 1 O'CLOCK AND ANOTHER AT ABOUT 11 O'CLOCK. NO ALT READOUTS ON ANY CONTACT. WE SPOTTED A SLOW MOVING ACFT AT OUR 12 O'CLOCK; QUITE A BIT BELOW US. APCH THEN ASKED IF OUR TFC WAS SBND. AT THAT MOMENT THE CAPT LOOKED OUT HIS LEFT WINDSHIELD AND SPOTTED AN SMA (YELLOW AND WHITE) HDG 90 DEGS TO US. IT WAS CONSTANT BEARING DECREASING DISTANCE AT 5000'; OUR ALT. THE CAPT CALLED THE TFC AND DETERMINED THAT EVASIVE ACTION WOULD NOT BE NECESSARY. THE SMA PASSED DIRECTLY BEHIND US WITH APPROX 200' LAT SEP AND NO HORIZ SEP. FIVE OR SIX SECS DIFFERENCE WOULD HAVE SEEN 2 ACFT AND MANY PAX SCATTERED OVER N TX. SOME OBSERVATIONS: 1) THE SMA APPEARED TO BE IN A TCA AND NOT IN CONTACT WITH ATC. 2) THE CIVILIAN WAS DEFINITELY FLYING DIRECTLY THROUGH A JET ARR AREA AT AN AWKWARD ALT (IE; A TURBO JET VECTOR ALT). 3) ATC DID NOT STRESS THE CLOSING TFC WHICH WAS THE REAL CONFLICT IN THEIR CALLS. FLT CREW ATTN WAS DISTRACTED BY THE OTHER CALLS. HOWEVER; SINCE THERE WAS NO ALT READOUT; IT WAS HARD FOR APCH TO KNOW WHICH TARGET WAS MOST DANGEROUS. 4) THERE PROBABLY WOULD NOT HAVE BEEN TIME TO TAKE EVASIVE ACTION IF IT HAD BEEN NECESSARY. WE WERE VERY LUCKY. 5) A MITIGATING CIRCUMSTANCE MAY HAVE BEEN A POSSIBLE ACFT MISHAP (CRASH) VERY NEARBY. THE ATC CTLR PRIOR TO APCH HAD BEEN EVIDENTLY TRYING TO CTL AND DIRECT SEARCH AND RESCUE EFFORTS. SUPPLEMENTAL INFO FROM ACN 82588: THESE TYPES OF INCIDENTS COULD BE PREVENTED IF ALL ACFT WERE REQUIRED TO HAVE A TRANSPONDER AND BE IN RADIO CONTACT WITH CTLING AGENCY WHEN FLYING NEAR ARPTS AND ALONG JET ARR ROUTES TO THESE ARPTS. THIS SMA WAS FLYING IN THE DFW TCA W/O EITHER.