AIM change 2 effective September 13, 2018

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Update includes traffic advisories at non-towered airports, STARs, weather services and more

AIM Change 2 went into effect September 13 and includes recommended advisory practices at non-towered airports as well as weather services and standard terminal arrivals (STARs). The changes include:

Use the published airport name when communicating at non-towered airports.

4−1−9. Traffic Advisory Practices at Airports Without Operating Control Towers This change adds a recommended practice instructing pilots to use the correct airport name as identified in appropriate aeronautical publications. It also emphasizes the importance of utilizing the common traffic advisory frequency (CTAF) and making accurate position calls at the recommended intervals.

The update serves as a reminder to avoid local language that may not be universally understood for transient pilots or even pilots new to the area. Avoiding potentially unknown local landmarks in favor of cardinal position and distance from the airport is a fundamental principle of effective communication at non-towered airports.

When departing an airport, make an advisory call prior to taxi (include where you are and where you are going) and again before taking the runway for departure (include direction of flight). When inbound to a non-towered airport, make an advisory call 10 miles from the airport with your position and intentions and do so again when entering the downwind, base and final legs. Another call should be made once you have vacated the runway so departing traffic is aware that the runway is clear. Keep it simple, brief and informative as in, “Clermont County Traffic, Skyhawk Three Uniform Charlie, left downwind, Runway 22, Clermont County.”

Adhering to these standard practices is vitally important to avoiding collisions and ensuring pilots have consistent expectations throughout our airspace.  While common sense should prevail and slight modifications may be necessary, especially in a particularly congested traffic pattern, pilots should routinely practice these standard procedures.

“Descend via” allows the pilot to descend at his discretion to meet restrictions.

5−4−1. Standard Terminal Arrival (STAR) Procedures This change clarifies that once a Descend Via clearance is issued, pilots are allowed to begin a descent while still navigating inbound to a STAR. The previous language was vague, referring simply to pilots “on” STARs.

As background, a STAR is a published arrival route created for higher volume airports to affect the orderly flow of arriving aircraft. STARs simplify clearance procedures and also facilitate transition between en route flying and approach procedures.

Pilots navigating on a STAR must maintain the last assigned altitude until receiving authorization to descend so as to comply with all published altitude restrictions which may include the ATC phraseology “DESCEND VIA.” Clearance to “descend via” authorizes pilots to descend at pilot’s discretion to meet published restrictions. For most airliners, the task of complying with multiple altitude restrictions is much easier with the use of automation and flight management systems.

For light aircraft without the benefit of more advanced avionics, the task becomes more cumbersome and requires accurate mental math or the use of vertical navigation calculations using a flight computer or GPS navigator installed on the airplane. If you’re flying to an airport in the IFR system with published STARs, you should anticipate making use of these published routes unless noted in your flight plan that you are unable to accept a STAR assignment.

Ensure your preflight information is coming from a reliable source.

7−1−2. FAA Weather Services 7−1−3. Use of Aviation Weather Products 7−1−5. Preflight Briefing This change updates information regarding contract FAA weather services available via the Internet as a primary source for obtaining preflight briefings and filing flight plans. This change also reflects the cancellation of the Direct Users Access Terminal (DUATS II) contract held by Lockheed Martin and CSRA.

The update reflects the multitude of resources available to pilots for weather and other preflight information. Pilots should be reminder to verify the type of weather product being examined (for example, current weather or forecast weather), the currency of the product (that is, product issue and valid times), and the relevance of the product. Pilots should also be cautious when using unfamiliar products, or products not supported by FAA/NWS technical specifications.

For a complete description of the most recent AIM changes, visit or purchase your hard copy of the FAR/AIM here.