TAAs are the method by which aircraft are transitioned from the RNAV en route structure to the terminal area with minimal ATC interaction. Terminal arrival areas are depicted in the planview of the approach chart, and each waypoint associated with them is also provided with a unique five character, pronounceable name. The TAA consists of a designated volume of airspace designed to allow aircraft to enter a protected area, offering guaranteed obstacle clearance where the initial approach course is intercepted based on the location of the aircraft relative to the airport. Where possible, TAAs are developed as a basic T shape that is divided into three separate arrival areas around the head of the T: left base, right base, and straight-in. Typically, the TAA offers an IAF at each of these three arrival areas that are 3-6 NM from an IF, which often doubles as the IAF for straight-in approaches, a FAF located approximately 5 NM from the runway threshold, and a MAP. [Figure 5-33 on page 5-46]

Figure 5-33.Terminal Arrival Area Design (Basic T).

Procedurally, pilots may be cleared to an IAF associated with the TAA. ATC expects the flight to proceed to the IAF and maintain the altitude depicted for that area of the TAA, unless cleared otherwise. An obstacle clearance of at least 1,000 feet is guaranteed within the boundaries of the TAA.

TAAs are modified or even eliminated if necessary to meet the requirements of a specific airport and surrounding terrain, or airspace considerations negating the use of the T approach design concept. Alternative designs are addressed in FAA Order 8260.45A, Terminal Arrival Area (TAA) Design Criteria. Variations may eliminate one or both base areas, and/or limit or modify the angular size of the straight-in area. When both base areas are eliminated, TAAs are not depicted in the planview. Normally, a portion of the TAA underlies an airway. If this is not the case, at least one feeder route is provided from an airway fix or NAVAID to the TAA boundary. The feeder route provides a direct course from the en route fix/NAVAID to the appropriate IF/IAF. Multiple feeder routes may also be established. In some cases, TAAs may not be depicted because of airspace congestion or other operational requirements. [Figure 5-34]