Following the successful changes to Common Traffic Advisory Frequencies (CTAFs) in the Mat-Su Valley last May, the Glenn Highway corridor between Anchorage and Palmer is now the focus of the industry/government working group established to explore ways of reducing mid-air collisions. In previous working group meetings, issues were identified in the Glenn Highway corridor regarding the flow of VFR traffic, which is constrained by Restricted Areas and Class D airspace on the west, and mountainous terrain to the east. In addition, there are potential inconsistencies with altitudes and frequencies recommended by charts, the AIM, and the Alaska Supplement. The group is now undertaking an examination of flight routes, CTAF assignments and use patterns along the Glenn Highway, to see if changes might be recommended to improve aviation safety along this busy flight corridor.
The Mat Su working group is comprised of pilots, flight instructors, Part 135 operators, and representatives from aviation organization and government agencies, including the FAA, the National Institute for Occupational Safety and Health and the military. The working group was established on late 2011, following a number mid-air collisions that occurred that summer. After examining how airspace is used by civil as well as military users, learning what FAA services are provided, and considering a variety of alternatives, the ad hoc group made recommendations to government and industry groups encouraging use of anti-collision lighting, and changes to the distribution of CTAF frequencies. A major milestone was achieved last May with the re-allocation of individual airport CTAFs, and the creation of new CTAF Areas in the Mat Su Valley. The new CTAF areas in use are now documented in airport facility directories, diagrams in the Notices section of the Alaska Supplement, an insert on the Anchorage/Fairbanks Terminal Area Chart and through the creation of a color Google Earth based map that was widely distributed last spring and summer.
CTAF Area defined in the AIM
Another result from this initiative has been a change in definition for Common Traffic Advisory Frequencies in the Aeronautical Information Manual (AIM). Previously, a CTAF was only defined as a 10 mile radius around an airport or landing area, without an operating control tower. The definition has been modified to recognize, in Alaska only, that a CTAF Area may be designated for the purpose of carrying out advisory practices while operating in designated areas with a high volume of VFR traffic. Pilots are encouraged to use the appropriate common frequency throughout the area, if they are not in contact with Air Traffic Control. Alaska has had a number of CTAF areas created where concentrations of traffic exist in areas that otherwise lack ATC Services. In addition to the Anchorage area, CTAF areas are found in locations such as Juneau, in the White Mountains north of Fairbanks and in oil fields on the North Slope. See Section 4-1-9 and Table 4-1-1 in the AIM for a complete description of the new definitions.
Glenn Highway Corridor
The current focus of the working group is to examine the Glenn Highway corridor, between Palmer and the Anchorage airports, continuing down to Cook Inlet. Already the group has reviewed the existing CTAF frequencies in use in the area. They also heard presentations by Air Force and Army representatives describing typical flight routes and traffic patterns used during training missions, including use of unmanned aircraft and artillery practice. In future meetings, presentations by Air Traffic Control, civil flight training (fixed wing and helicopter), tour operators and other local users are planned. The group will also review the results of a 2012 pilot survey and other feedback before considering possible changes. If you would like more information on the activities of the working group, please contact me at firstname.lastname@example.org.