AIM ¶ 5-6-15 — ADIZ Boundaries

AIM paragraph 5-6-15 is a reference paragraph that points pilots to FIG 5-6-3, which graphically depicts two important pieces of airspace information:

• Air Defense Identification Zone (ADIZ) boundaries — the lateral limits of areas where aircraft must be readily identified in the interest of national security.
• Designated Mountainous Areas — regions where special rules and higher obstacle clearance requirements apply (for example, IFR obstacle clearance increases from 1,000 ft to 2,000 ft above the highest obstacle within the route width).

Why it matters operationally:

• Before any flight near a U.S. border or coastline, you should consult the figure to determine if your route penetrates an ADIZ, which triggers flight plan, two-way radio, and transponder requirements under 14 CFR Part 99.
• When planning IFR routes or computing minimum en route altitudes in the western U.S., Alaska, Hawaii, Puerto Rico, or parts of the eastern U.S., you must know whether your route lies within a designated mountainous area because it affects MEAs, OROCAs, and required obstacle clearance.

AIM information is advisory, but the underlying ADIZ and mountainous-area rules are regulatory.