Narrative:

Aircraft #1 (small aircraft X) was sebnd on the terre haute 164 degree right at 6000'. Aircraft #2 (small transport Y) was nwbnd on V243 (terre haute 164 degree right) at 6000'. When the aircraft were approximately 2 mi apart the controller noted that the aircraft were on merging courses and immediately issued turns to both aircraft to achieve sep. Aircraft #1 was originally routed V171 after terre haute which would have provided adequate sep, but the controller issued a preferential routing 40 mi prior to the confliction point which resulted in the incident. Aircraft #1 was also flying at a wrong altitude for direction of flight. This had been approved by the controller prior to the confliction point which resulted in the incident. Aircraft #1 was also flying at a wrong altitude for direction of flight. This had been approved by the controller prior to either aircraft appearing on the radar scope. Both aircraft appeared on the scope at about the same time at points approximately 100 mi apart. Just prior to the incident the controller was busy with multiple apches at the primary airport. This, plus the fact that aircraft #1 overflew the primary airport 12 mi prior to the confliction and the data blocks on the radar were overlapping contributed to his failure to recognize the situation and resolve the conflict. I feel that future occurrences of this type could be avoided by refusing to allow aircraft to transition the airspace at the wrong altitude. In this situation there was no operational advantage gained by allowing the wrong altitude for direction of flight. The controller was just trying to be accommodating to the pilot's request. The result was an operational error. Also, at times when the radar controller is busy it would be helpful to have another radar controller available as an extra pair of eyes to help with the spotting of potential problems. In conclusion, I feel that this operational error resulted from the controller's attention being diverted to a different part of the radar scope and by his approval of the overflt by aircraft #1 at the wrong altitude for direction of flight.

Google
 

Original NASA ASRS Text

Title: SMA AND SMT, OPPOSITE DIRECTION ON SAME AIRWAY AT SAME ALT ARE ALLOWED TO COME INTO CONFLICT DUE TO CTLR BEING DISTRACTED TO ANOTHER PART OF HIS SCOPE.

Narrative: ACFT #1 (SMA X) WAS SEBND ON THE TERRE HAUTE 164 DEG R AT 6000'. ACFT #2 (SMT Y) WAS NWBND ON V243 (TERRE HAUTE 164 DEG R) AT 6000'. WHEN THE ACFT WERE APPROX 2 MI APART THE CTLR NOTED THAT THE ACFT WERE ON MERGING COURSES AND IMMEDIATELY ISSUED TURNS TO BOTH ACFT TO ACHIEVE SEP. ACFT #1 WAS ORIGINALLY ROUTED V171 AFTER TERRE HAUTE WHICH WOULD HAVE PROVIDED ADEQUATE SEP, BUT THE CTLR ISSUED A PREFERENTIAL ROUTING 40 MI PRIOR TO THE CONFLICTION POINT WHICH RESULTED IN THE INCIDENT. ACFT #1 WAS ALSO FLYING AT A WRONG ALT FOR DIRECTION OF FLT. THIS HAD BEEN APPROVED BY THE CTLR PRIOR TO THE CONFLICTION POINT WHICH RESULTED IN THE INCIDENT. ACFT #1 WAS ALSO FLYING AT A WRONG ALT FOR DIRECTION OF FLT. THIS HAD BEEN APPROVED BY THE CTLR PRIOR TO EITHER ACFT APPEARING ON THE RADAR SCOPE. BOTH ACFT APPEARED ON THE SCOPE AT ABOUT THE SAME TIME AT POINTS APPROX 100 MI APART. JUST PRIOR TO THE INCIDENT THE CTLR WAS BUSY WITH MULTIPLE APCHES AT THE PRIMARY ARPT. THIS, PLUS THE FACT THAT ACFT #1 OVERFLEW THE PRIMARY ARPT 12 MI PRIOR TO THE CONFLICTION AND THE DATA BLOCKS ON THE RADAR WERE OVERLAPPING CONTRIBUTED TO HIS FAILURE TO RECOGNIZE THE SITUATION AND RESOLVE THE CONFLICT. I FEEL THAT FUTURE OCCURRENCES OF THIS TYPE COULD BE AVOIDED BY REFUSING TO ALLOW ACFT TO TRANSITION THE AIRSPACE AT THE WRONG ALT. IN THIS SITUATION THERE WAS NO OPERATIONAL ADVANTAGE GAINED BY ALLOWING THE WRONG ALT FOR DIRECTION OF FLT. THE CTLR WAS JUST TRYING TO BE ACCOMMODATING TO THE PLT'S REQUEST. THE RESULT WAS AN OPERROR. ALSO, AT TIMES WHEN THE RADAR CTLR IS BUSY IT WOULD BE HELPFUL TO HAVE ANOTHER RADAR CTLR AVAILABLE AS AN EXTRA PAIR OF EYES TO HELP WITH THE SPOTTING OF POTENTIAL PROBS. IN CONCLUSION, I FEEL THAT THIS OPERROR RESULTED FROM THE CTLR'S ATTN BEING DIVERTED TO A DIFFERENT PART OF THE RADAR SCOPE AND BY HIS APPROVAL OF THE OVERFLT BY ACFT #1 AT THE WRONG ALT FOR DIRECTION OF FLT.

Data retrieved from NASA's ASRS site as of August 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.