Narrative:

The GLF5 (aircraft X) was inbound hky from the north. Told to expect visual runway 24. The patz (aircraft Y) was shooting practice approachs to hky in VFR conditions. The patz was on a missed approach 7-10 mi north of the airport. Aircraft 1 was issued the patz as traffic and another unknown VFR on the final to hky indicting 2900 ft. The GLF5, without advising and without clearance, was proceeding to tawba, the NDB OM for hky. The GLF5 also advised he was 'painting' both VFR's. The GLF5 turned himself onto the localizer (again without advising or a clearance) right on top of the unknown VFR. The GLF5 finally picked up the airport on a 5 mi final. Cleared for visual, terminated and switched to the tower. The patz called and said he had run into a snow shower. He asked for an IFR clearance. I cleared him direct tawba at 3400 ft. 3400 ft is the mia. The GLF5 made a 360 degree turn on a 1 mi final. He was at 2400 ft so I let the patz continue to tawba. The GLF5 extended, trying to get behind the other VFR and rose to 2600 ft while turning base. I turned the patz to a 090 degree heading and climbed him to 4000 ft. I didn't measure the distance but it was right at 5 mi. This is the third time I've seen an aircraft use TCASII to try to run a VFR off the final. It's dangerous and should stop. I feel totally disconnected from the WX since ASOS and AWOS began. I was completely surprised by the visual and the snow showers. I have no idea if this could have been/was an operational error, a pilot deviation or none of the above. I think a little training is called for. Callback conversation with reporter revealed the following information: reporter expressed concern with what he perceives as a more aggressive use of TCASII by pilots. He states that when the pilot was issued traffic and could not see the traffic, pre TCAS, the pilot was 'more cautious' about the traffic call until traffic was in sight. The reporter has recently perceived that TCASII equipped aircraft will now 'run up' closer to the traffic before taking whatever action is 'necessary' for the situation. This 'more bold' nature causes him overall concern. The reporter states that ASOS WX changes do not 'alarm' in the control areas, thus not alerting the controller to changes which might affect traffic sequencing and tower coordination.

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Original NASA ASRS Text

Title: ZTL RADAR CTLR CONCERNED WITH NON COORD FLT PATH DEV OF GV FLC ON VISUAL APCH TO HKY ARPT. GV THEN OBSERVED MAKING ADDITIONAL TFC PATTERN DEV REQUIRING CTLR TO AMEND IFR CTL INSTRUCTIONS FOR AN INBOUND PATZ.

Narrative: THE GLF5 (ACFT X) WAS INBOUND HKY FROM THE N. TOLD TO EXPECT VISUAL RWY 24. THE PATZ (ACFT Y) WAS SHOOTING PRACTICE APCHS TO HKY IN VFR CONDITIONS. THE PATZ WAS ON A MISSED APCH 7-10 MI N OF THE ARPT. ACFT 1 WAS ISSUED THE PATZ AS TFC AND ANOTHER UNKNOWN VFR ON THE FINAL TO HKY INDICTING 2900 FT. THE GLF5, WITHOUT ADVISING AND WITHOUT CLRNC, WAS PROCEEDING TO TAWBA, THE NDB OM FOR HKY. THE GLF5 ALSO ADVISED HE WAS 'PAINTING' BOTH VFR'S. THE GLF5 TURNED HIMSELF ONTO THE LOC (AGAIN WITHOUT ADVISING OR A CLRNC) RIGHT ON TOP OF THE UNKNOWN VFR. THE GLF5 FINALLY PICKED UP THE ARPT ON A 5 MI FINAL. CLRED FOR VISUAL, TERMINATED AND SWITCHED TO THE TWR. THE PATZ CALLED AND SAID HE HAD RUN INTO A SNOW SHOWER. HE ASKED FOR AN IFR CLRNC. I CLRED HIM DIRECT TAWBA AT 3400 FT. 3400 FT IS THE MIA. THE GLF5 MADE A 360 DEG TURN ON A 1 MI FINAL. HE WAS AT 2400 FT SO I LET THE PATZ CONTINUE TO TAWBA. THE GLF5 EXTENDED, TRYING TO GET BEHIND THE OTHER VFR AND ROSE TO 2600 FT WHILE TURNING BASE. I TURNED THE PATZ TO A 090 DEG HDG AND CLBED HIM TO 4000 FT. I DIDN'T MEASURE THE DISTANCE BUT IT WAS RIGHT AT 5 MI. THIS IS THE THIRD TIME I'VE SEEN AN ACFT USE TCASII TO TRY TO RUN A VFR OFF THE FINAL. IT'S DANGEROUS AND SHOULD STOP. I FEEL TOTALLY DISCONNECTED FROM THE WX SINCE ASOS AND AWOS BEGAN. I WAS COMPLETELY SURPRISED BY THE VISUAL AND THE SNOW SHOWERS. I HAVE NO IDEA IF THIS COULD HAVE BEEN/WAS AN OPERROR, A PLTDEV OR NONE OF THE ABOVE. I THINK A LITTLE TRAINING IS CALLED FOR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR EXPRESSED CONCERN WITH WHAT HE PERCEIVES AS A MORE AGGRESSIVE USE OF TCASII BY PLTS. HE STATES THAT WHEN THE PLT WAS ISSUED TFC AND COULD NOT SEE THE TFC, PRE TCAS, THE PLT WAS 'MORE CAUTIOUS' ABOUT THE TFC CALL UNTIL TFC WAS IN SIGHT. THE RPTR HAS RECENTLY PERCEIVED THAT TCASII EQUIPPED ACFT WILL NOW 'RUN UP' CLOSER TO THE TFC BEFORE TAKING WHATEVER ACTION IS 'NECESSARY' FOR THE SIT. THIS 'MORE BOLD' NATURE CAUSES HIM OVERALL CONCERN. THE RPTR STATES THAT ASOS WX CHANGES DO NOT 'ALARM' IN THE CTL AREAS, THUS NOT ALERTING THE CTLR TO CHANGES WHICH MIGHT AFFECT TFC SEQUENCING AND TWR COORD.

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.