Narrative:

While I was working local 2/helicopter control combined; I coordinated with local 1 for them to depart aircraft X on a SID in my airspace (abcd departure.) it was coordinated at that time that I would follow aircraft X with aircraft Y on a SID in local 1's airspace (efgh departure;) on a heading of 210; a common practice. Shortly after; local 1 coordinated with me that aircraft X was rolling. I had previously instructed aircraft Y to line up and wait in anticipation of following the aircraft X aircraft. During this time; another controller had come to relieve me. It was my intention to utilize visual separation between the 2 departures; with aircraft Y turning in behind the departing aircraft X while keeping him in sight. Normally; in this situation; I would prep the pilot into expecting visual separation by advising him of the other aircraft and to be looking for it while simultaneously issuing a take off clearance. In this case; as another controller was coming in to relieve me; my attention was temporarily diverted to standing up and getting out of the other controller's way. It was during this time that I issued a take off clearance to aircraft Y; without any mention of visual separation or the aircraft X departing the other runway complex ahead of him. As aircraft Y began his take off roll; I began my position relief briefing. During my briefing; I simultaneously issued instructions to a previous departure; issued a landing clearance to another aircraft; coordinated my departure to local 1; and received instructions from the traffic manager on a sequence of upcoming departures. It was all of these other things that diverted my full attention from the briefing; especially while I was trying to comprehend the instructions the traffic manager was giving me. As a result; I failed to brief to the next controller that visual separation still needed to be applied between the 2 aircraft; and they came too close. Even though I utilized the position relief checklist; all of the distractions during my relief briefing caused me to forget this information; important as it was. I did mention that aircraft Y was rolling during the brief; and the other controller was present when I issued those instructions; but I did not advise the relieving controller of the aircraft X aircraft; nor that aircraft Y still needed to be issued visual separation instructions. When the relieving controller took over the position; he told aircraft Y to contact departure. As he was issuing these instructions; I realized my mistake and was about to advise him when he noticed the proximity of the 2 aircraft himself. He attempted to retain aircraft Y on frequency in order to get the visual; but aircraft Y had already left the frequency. The aircraft were almost separated vertically; since they were 1000 feet apart; however for a brief moment the 2 aircraft came within 900 feet vertically; without the appropriate visual separation being applied. Recommendation; in the future I will attempt to ensure that getting relieved will not interrupt my routine. Although it wasn't busy at the time; all of the coordination being done was a bit complex; and I was distracted from the overall picture of traffic; and gave an incomplete briefing. While it isn't realistic to wait until there is little or no traffic before giving a relief briefing; I will no longer begin a briefing until I at least 'close the loop;' on all pending actions and coordinations. I shouldn't leave any 'loose ends' for the relieving controller to finish on my behalf. I will pick a better spot in order to start a briefing in the future.

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Original NASA ASRS Text

Title: Tower Local Controller described a loss of separation event involving simultaneous parallel runway departures; the reporter listing the distraction of the relief briefing as a causal factor.

Narrative: While I was working Local 2/Helicopter Control combined; I coordinated with Local 1 for them to depart Aircraft X on a SID in my airspace (ABCD departure.) It was coordinated at that time that I would follow Aircraft X with Aircraft Y on a SID in Local 1's airspace (EFGH departure;) on a heading of 210; a common practice. Shortly after; Local 1 coordinated with me that Aircraft X was rolling. I had previously instructed Aircraft Y to line up and wait in anticipation of following the Aircraft X aircraft. During this time; another controller had come to relieve me. It was my intention to utilize visual separation between the 2 departures; with Aircraft Y turning in behind the departing Aircraft X while keeping him in sight. Normally; in this situation; I would prep the pilot into expecting visual separation by advising him of the other aircraft and to be looking for it while simultaneously issuing a take off clearance. In this case; as another controller was coming in to relieve me; my attention was temporarily diverted to standing up and getting out of the other controller's way. It was during this time that I issued a take off clearance to Aircraft Y; without any mention of visual separation or the Aircraft X departing the other runway complex ahead of him. As Aircraft Y began his take off roll; I began my position relief briefing. During my briefing; I simultaneously issued instructions to a previous departure; issued a landing clearance to another aircraft; coordinated my departure to Local 1; and received instructions from the Traffic Manager on a sequence of upcoming departures. It was all of these other things that diverted my full attention from the briefing; especially while I was trying to comprehend the instructions the Traffic Manager was giving me. As a result; I failed to brief to the next controller that visual separation still needed to be applied between the 2 aircraft; and they came too close. Even though I utilized the position relief checklist; all of the distractions during my relief briefing caused me to forget this information; important as it was. I did mention that Aircraft Y was rolling during the brief; and the other controller was present when I issued those instructions; but I did not advise the relieving controller of the Aircraft X aircraft; nor that Aircraft Y still needed to be issued visual separation instructions. When the relieving controller took over the position; he told Aircraft Y to contact departure. As he was issuing these instructions; I realized my mistake and was about to advise him when he noticed the proximity of the 2 aircraft himself. He attempted to retain Aircraft Y on frequency in order to get the visual; but Aircraft Y had already left the frequency. The aircraft were almost separated vertically; since they were 1000 feet apart; however for a brief moment the 2 aircraft came within 900 feet vertically; without the appropriate visual separation being applied. Recommendation; in the future I will attempt to ensure that getting relieved will not interrupt my routine. Although it wasn't busy at the time; all of the coordination being done was a bit complex; and I was distracted from the overall picture of traffic; and gave an incomplete briefing. While it isn't realistic to wait until there is little or no traffic before giving a relief briefing; I will no longer begin a briefing until I at least 'close the loop;' on all pending actions and coordinations. I shouldn't leave any 'loose ends' for the relieving controller to finish on my behalf. I will pick a better spot in order to start a briefing in the future.

Data retrieved from NASA's ASRS site as of April 2012 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.