AIM

4/3/14

5−4−12

Arrival Procedures

FIG 5

−4−7

TAA Area

5.

The standard TAA consists of three areas

defined by the extension of the IAF legs and the

intermediate segment course. These areas are called

the straight−in, left−base, and right−base areas. (See

FIG 5−4−7). TAA area lateral boundaries are

identified by magnetic courses TO the IF (IAF). The

straight−in area can be further divided into

pie−shaped sectors with the boundaries identified by

magnetic courses TO the IF (IAF), and may contain

stepdown sections defined by arcs based on RNAV

distances (DME or ATD) from the IF (IAF). The

right/left−base areas can only be subdivided using

arcs based on RNAV distances from the IAFs for

those areas. Minimum MSL altitudes are charted

within each of these defined areas/subdivisions that

provide at least 1,000 feet of obstacle clearance, or

more as necessary in mountainous areas.

(a)

Prior to arriving at the TAA boundary, the

pilot can determine which area of the TAA the aircraft

will enter by selecting the IF (IAF) to determine the

magnetic bearing TO the center IF (IAF). That

bearing should then be compared with the published

bearings that define the lateral boundaries of the TAA

areas. Using the end IAFs may give a false indication

of which area the aircraft will enter. This is critical

when approaching the TAA near the extended

boundary between the left and right−base areas,

especially where these areas contain different

minimum altitude requirements.

(b)

Pilots entering the TAA and cleared by air

traffic control, are expected to proceed directly to the

IAF associated with that area of the TAA at the

altitude depicted, unless otherwise cleared by air

traffic control. Cleared direct to an Initial Approach

Fix (IAF) without a clearance for the procedure does

not authorize a pilot to descend to a lower TAA

altitude. If a pilot desires a lower altitude without an

approach clearance, request the lower TAA altitude.

If a pilot is not sure of what they are authorized or

expected to do by air traffic, they should ask air traffic

or request a specific clearance. Pilots entering the

TAA with two−way radio communications failure

(14 CFR Section 91.185, IFR Operations: Two−way

Radio Communications Failure), must maintain the

highest altitude prescribed by Section 91.185(c)(2)

until arriving at the appropriate IAF.