Narrative:

Inbound from ioc to apa, called tower at ioc and was told to follow t-tail (small aircraft #1) (who had incorrectly reported position) which was in sight. After landing, pilot of small aircraft #2 fixed gear single, informed me we had nearly collided. I had passed on his left 'about 50 ft.' my TCASII did indicate a target at 0.1 NM that I didn't see. That indicates plus or minus 500 ft separation, but he said 50 ft, my speed about 50 KIAS faster. I never saw him as was looking at 11 O'clock position at small aircraft #1. I doubt the 50 ft, but tower should have called both targets to me, not just the small aircraft #1. They were not talking to small aircraft #2. Apa tower does not call traffic well and has noticed a severe deterioration in traffic control tower in recent months. I have been flying based at apa for 11 yrs. I had 2 conflicts this day. The other is on a separate form. Many pilots are complaining. Callback conversation with reporter revealed the following information: left word with the reporter that the airspace within his area of conflicting traffic was not in the apa tower control but in the den approach airspace and outside of the TCA wherein, when VFR, the see and avoid concept is used. Therefore, his comment regarding the apa tower with regard to their control effectiveness was not appropriate since they would have no knowledge, except when the aircraft report to the tower and give their position as did the #1 aircraft given as an advisory.

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Original NASA ASRS Text

Title: PLT OF GA SMA ACFT HAD NMAC WITH ANOTHER ACFT UNKNOWN DURING DSCNT CRUISE TO LAND.

Narrative: INBOUND FROM IOC TO APA, CALLED TWR AT IOC AND WAS TOLD TO FOLLOW T-TAIL (SMA #1) (WHO HAD INCORRECTLY RPTED POS) WHICH WAS IN SIGHT. AFTER LNDG, PLT OF SMA #2 FIXED GEAR SINGLE, INFORMED ME WE HAD NEARLY COLLIDED. I HAD PASSED ON HIS L 'ABOUT 50 FT.' MY TCASII DID INDICATE A TARGET AT 0.1 NM THAT I DIDN'T SEE. THAT INDICATES PLUS OR MINUS 500 FT SEPARATION, BUT HE SAID 50 FT, MY SPD ABOUT 50 KIAS FASTER. I NEVER SAW HIM AS WAS LOOKING AT 11 O'CLOCK POS AT SMA #1. I DOUBT THE 50 FT, BUT TWR SHOULD HAVE CALLED BOTH TARGETS TO ME, NOT JUST THE SMA #1. THEY WERE NOT TALKING TO SMA #2. APA TWR DOES NOT CALL TFC WELL AND HAS NOTICED A SEVERE DETERIORATION IN TFC CTL TWR IN RECENT MONTHS. I HAVE BEEN FLYING BASED AT APA FOR 11 YRS. I HAD 2 CONFLICTS THIS DAY. THE OTHER IS ON A SEPARATE FORM. MANY PLTS ARE COMPLAINING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: LEFT WORD WITH THE RPTR THAT THE AIRSPACE WITHIN HIS AREA OF CONFLICTING TFC WAS NOT IN THE APA TWR CTL BUT IN THE DEN APCH AIRSPACE AND OUTSIDE OF THE TCA WHEREIN, WHEN VFR, THE SEE AND AVOID CONCEPT IS USED. THEREFORE, HIS COMMENT REGARDING THE APA TWR WITH REGARD TO THEIR CTL EFFECTIVENESS WAS NOT APPROPRIATE SINCE THEY WOULD HAVE NO KNOWLEDGE, EXCEPT WHEN THE ACFT RPT TO THE TWR AND GIVE THEIR POS AS DID THE #1 ACFT GIVEN AS AN ADVISORY.

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.