Narrative:

I was conducting OJT on departure radar south. Air carrier X departed runway 27L; runway 27R; the normal departure runway had a disabled aircraft on it; on the nov RNAV SID. It was apparent air carrier X was south of the RNAV tracked. A few miles behind him air carrier Y departed on the daw RNAV SID on track. Air carrier X checked on stating he was having issues with his compass and would be deviating from the RNAV departure. Air carrier X had already compromised separation between himself and air carrier Y. Unfortunately the developmental's reply was 'roger'. I immediately told him to turn air carrier X and he assigned a 270 heading. Air carrier Y was still on the tower frequency. I promptly called local control 3 and told him air carrier X had compass issues; was assigned a 270 and to assign air carrier Y a 255 heading to ensure separation. A80 has a waiver for reduced departure separation. Thankfully; dr-north had no departures on the westbound RNAV heading because assigning. Air carrier X a 270 vector would have compromised separation between those 2 tracks. Atl tower needs to ensure aircraft are on the correct track; hold onto the aircraft until this occurs. In this case if tower had both aircraft on frequency visual separation could have been applied. Air carrier X should have advised the tower of his situation. Not check on departure already deviating into the path of air carrier Y.

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Original NASA ASRS Text

Title: A80 Controller providing OJT described a loss of separation event when traffic departing on an RNAV SID experienced equipment difficulties straying from the published route and conflicted with parallel runway departure traffic.

Narrative: I was conducting OJT on departure RADAR South. Air Carrier X departed Runway 27L; Runway 27R; the normal departure runway had a disabled aircraft on it; on the NOV RNAV SID. It was apparent Air Carrier X was south of the RNAV tracked. A few miles behind him Air Carrier Y departed on the DAW RNAV SID on track. Air Carrier X checked on stating he was having issues with his compass and would be deviating from the RNAV departure. Air Carrier X had already compromised separation between himself and Air Carrier Y. Unfortunately the Developmental's reply was 'roger'. I immediately told him to turn Air Carrier X and he assigned a 270 heading. Air Carrier Y was still on the Tower frequency. I promptly called Local Control 3 and told him Air Carrier X had compass issues; was assigned a 270 and to assign Air Carrier Y a 255 heading to ensure separation. A80 has a waiver for reduced departure separation. Thankfully; DR-N had no departures on the westbound RNAV heading because assigning. Air Carrier X a 270 vector would have compromised separation between those 2 tracks. ATL Tower needs to ensure aircraft are on the correct track; hold onto the aircraft until this occurs. In this case if Tower had both aircraft on frequency visual separation could have been applied. Air Carrier X should have advised the Tower of his situation. NOT check on departure already deviating into the path of Air Carrier Y.

Data retrieved from NASA's ASRS site as of July 2013 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.