Narrative:

I allowed my radar developmental to work the sector, even though it had become too busy and complex for her abilities. I should have been more active as the instructor. Air carrier X and air carrier Y, both non radar, FL190 and FL180 respectively, same route. Developmental allowed air carrier Y data block to remain stationary, coast track. She radar idented air carrier X and descended the aircraft through air carrier Y. The pilot of air carrier Y reported the incident on frequency, and may or may not report this as a near midair. Air carrier Y was on an incorrect beacon code, but since the aircraft was non radar, we had no way of knowing this. The data block did not follow the flight plan, thus the data block was not in the same position as the aircraft. When air carrier X came into radar coverage, the developmental did not see a target or data block on air carrier Y in that area, so she descended air carrier X. Poor radar coverage, wrong beacon code, and developmental's inability to keep up, all were contributory factors. I watched the developmental put herself into a very difficult situation, when I should not have let that happen. My desire for her to learn from her own mistakes resulted in the sector becoming unsafe.

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Original NASA ASRS Text

Title: ACR X DSCNT THROUGH OCCUPIED ALT HAD LTSS FROM ACR Y. SYS ERROR. CTLR TRAINING IN PROGRESS.

Narrative: I ALLOWED MY RADAR DEVELOPMENTAL TO WORK THE SECTOR, EVEN THOUGH IT HAD BECOME TOO BUSY AND COMPLEX FOR HER ABILITIES. I SHOULD HAVE BEEN MORE ACTIVE AS THE INSTRUCTOR. ACR X AND ACR Y, BOTH NON RADAR, FL190 AND FL180 RESPECTIVELY, SAME RTE. DEVELOPMENTAL ALLOWED ACR Y DATA BLOCK TO REMAIN STATIONARY, COAST TRACK. SHE RADAR IDENTED ACR X AND DSNDED THE ACFT THROUGH ACR Y. THE PLT OF ACR Y RPTED THE INCIDENT ON FREQ, AND MAY OR MAY NOT RPT THIS AS A NEAR MIDAIR. ACR Y WAS ON AN INCORRECT BEACON CODE, BUT SINCE THE ACFT WAS NON RADAR, WE HAD NO WAY OF KNOWING THIS. THE DATA BLOCK DID NOT FOLLOW THE FLT PLAN, THUS THE DATA BLOCK WAS NOT IN THE SAME POS AS THE ACFT. WHEN ACR X CAME INTO RADAR COVERAGE, THE DEVELOPMENTAL DID NOT SEE A TARGET OR DATA BLOCK ON ACR Y IN THAT AREA, SO SHE DSNDED ACR X. POOR RADAR COVERAGE, WRONG BEACON CODE, AND DEVELOPMENTAL'S INABILITY TO KEEP UP, ALL WERE CONTRIBUTORY FACTORS. I WATCHED THE DEVELOPMENTAL PUT HERSELF INTO A VERY DIFFICULT SIT, WHEN I SHOULD NOT HAVE LET THAT HAPPEN. MY DESIRE FOR HER TO LEARN FROM HER OWN MISTAKES RESULTED IN THE SECTOR BECOMING UNSAFE.

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.