Narrative:

My first contact was with a helicopter inbound for runway 31; I told him to continue and report the ballpark. A few minutes later a cessna contacted me at power line bend inbound for the lake; I told him to continue and report the ballpark for the west water lane. At this point the cessna was more than 3 miles in-trail of the helicopter and was for a different surface so I didn't call the traffic. After talking to a couple other aircraft both helicopter and the cessna reported the ballpark in sequence and were both cleared to land on their respective surfaces. I noticed the cessna was overtaking the helicopter so I looked through my binoculars and noticed him lower and to the outside of the helicopter. At this point I didn't issue the traffic since he appeared to have overtaken him already and the proximity did not appear to be unsafe. I assumed the cessna had the helicopter in sight since he had been gaining on him for over 3 miles and overtook him in what appeared to be a safe manner to me. While on final leg the pilot of the cessna asked the helicopter if he saw him; the helicopter pilot replied that he did see the 'blue cessna' pass him. The next day I was advised by management that the pilot of the cessna called stating that he did not want to file a complaint but wanted me to know that he felt the situation wasn't very safe and to be more aware of similar traffic situations in the future. Recommendation; to take more notice of the speed of aircraft that may not appear to be traffic for each other. To issue possible traffic further out so the pilot can be actively looking if I become busy with other aircraft. Have pilot's actively looking for other aircraft at all times and not rely solely on ATC advisories.

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Original NASA ASRS Text

Title: ANC controller described a conflict event involving a helicopter and Cessna inbound to different airport surfaces but from the same general arrival area; the reporter acknowledging traffic information was not issued.

Narrative: My first contact was with a helicopter inbound for Runway 31; I told him to continue and report the ballpark. A few minutes later a Cessna contacted me at power line bend inbound for the lake; I told him to continue and report the ballpark for the west water lane. At this point the Cessna was more than 3 miles in-trail of the helicopter and was for a different surface so I didn't call the traffic. After talking to a couple other aircraft both helicopter and the Cessna reported the ballpark in sequence and were both cleared to land on their respective surfaces. I noticed the Cessna was overtaking the Helicopter so I looked through my binoculars and noticed him lower and to the outside of the helicopter. At this point I didn't issue the traffic since he appeared to have overtaken him already and the proximity did not appear to be unsafe. I assumed the Cessna had the helicopter in sight since he had been gaining on him for over 3 miles and overtook him in what appeared to be a safe manner to me. While on final leg the pilot of the Cessna asked the helicopter if he saw him; the helicopter pilot replied that he did see the 'blue Cessna' pass him. The next day I was advised by Management that the pilot of the Cessna called stating that he did not want to file a complaint but wanted me to know that he felt the situation wasn't very safe and to be more aware of similar traffic situations in the future. Recommendation; to take more notice of the speed of aircraft that may not appear to be traffic for each other. To issue possible traffic further out so the pilot can be actively looking if I become busy with other aircraft. Have pilot's actively looking for other aircraft at all times and not rely solely on ATC advisories.

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.