Daniel Diggins

The definitions the FAA proposes to amend are not unique to the United States. They are internationally recognized standards, agreed to and accepted by all members of the International Civil Aviation Organization (ICAO), and signatories to the Chicago convention of 1944. The category III ILS approach is one of the most critical and high risk maneuvers in aviation as it allows landings with the lowest visibility values. To mitigate this risk, it is vital that flight crews follow very stringent and specific standards and procedures. A unilateral change of these standards by the United States will negate the current global harmony of these landing definitions, and compel international flight crews to train and operate differently in the United States versus the rest of the world. This could lead to confusion, which could have adverse safety ramifications. There is no indication that any kind of safety risk assessment was conducted to confirm or deny this possibility. New, performance based technology may have obviated the current sub definitions for the CAT III approach, and the FAA is to be commended for taking a leadership role to update this terminology, however, these changes should not be allowed to become effective until ICAO has changed the internationally recognized standard definitions, and all member states have concurred.