Background
On June 14, 2011, at approximately 1310 Alaska Daylight Time (ADT), a near mid-air collision (NMAC) occurred between Warbelow’s Air Ventures flight 401 (WAV401), a Raytheon-Beech 1900, and Era Alaska flight 12K (ERR12K), a Piper Navajo. Both aircraft were operating under visual flight rules. WAV401 was a scheduled Part 135 passenger flight from Galena to Fairbanks with two pilots and five passengers. ERR12K was an on-demand Part 135 charter flight from Fairbanks to Minto with one pilot and four passengers. There were no reports of injuries or damage to either aircraft.
Sequence of Events
The incident took place 3.5 nautical miles southwest of Fairbanks International Airport at approximately 2,100 feet. WAV401 was northeast bound toward the airport, descending to enter the traffic pattern for runway 20L, and was receiving radar service from Fairbanks Approach Control (FAI West Radar). ERR12K had just departed from runway 20R, climbing on a westbound heading, and was in communication with the FAI Air Traffic Control Tower local control position.
The tower controller issued three traffic advisories to ERR12K regarding WAV401, but the pilot of ERR12K never reported seeing the other aircraft. The approach controller issued no traffic information to WAV401 about ERR12K. Immediately after the aircraft crossed paths, the pilot of WAV401 reported that a Navajo had passed 100 feet above their aircraft. The approach controller then instructed WAV401 to contact the tower. After landing, the pilot of WAV401 requested telephone contact information for the tower. The incident was reported as a NMAC by the chief pilot of Warbelow’s Air Ventures about two hours later.
Radar Data
Review of radar data from the ASR-11 system near Fairbanks airport indicated that the radar targets of WAV401 and ERR12K merged with approximately 200 feet of vertical separation. The airspace surrounding Fairbanks is designated as a Terminal Radar Service Area (TRSA), where controllers are required to ensure that aircraft targets do not merge unless they have a minimum of 500 feet vertical separation or can maintain visual separation. Visual separation was not being applied in this incident.
Operational Errors
On June 18, the FAA reported two operational errors as a result of this incident: one for a loss of separation between ERR12K and WAV401, and a second for a minimum vectoring altitude violation involving ERR12K when the aircraft was assigned at or below 2,000 feet in an area where the minimum assignable altitude was 2,900 to 3,700 feet.
Personnel Statements
The pilot of WAV401 stated that the copilot initiated a descent after seeing the ERA aircraft approximately 100 to 150 feet above them. The controller stated he did not have the aircraft on radar. The FAI Controller in Charge (CIC) acknowledged that the local controller tried to establish 500 feet of vertical separation by issuing altitude restrictions and traffic calls, but assumed the approach controller was keeping WAV401 high. The CIC noted that there was no coordination between tower and approach, which he called a mistake on his part.
The local controller, who had been certified less than two months, stated that she did not notice a conflict alert until after the aircraft passed. She reported that classroom training at FAI was largely generic and did not cover specific TRSA separation procedures. Both controllers noted that opposite direction operations were frequently approved, contributing to the complex traffic situation.
Conclusion
The incident highlighted coordination deficiencies between approach control and tower, as well as training gaps related to TRSA operations. No causal analysis is provided in the source.