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United States Department of Transportation United States Department of Transportation

AC 20-191 - Airworthiness Approval of Airborne Systems used for Takeoff, Precision Approach, Landing and Rollout in low-visibility conditions

Document Information

Number
20-191
Title
Airworthiness Approval of Airborne Systems used for Takeoff, Precision Approach, Landing and Rollout in low-visibility conditions
Status
Active
Date issued
2026-05-20
Office of Primary Responsibility
AIR-626, Human Machine Interface Section
Description

This advisory circular (AC) provides an acceptable means of compliance for airworthiness criteria for low visibility takeoff, final approach, landing, and rollout in Category (CAT) II and CAT III weather minima. While the airworthiness criteria for low visibility takeoff is generic in nature, the criteria for the precision approach, landing, and rollout are tailored to using Instrument Landing System (ILS), and Ground Based Augmentation System (GBAS) and it is airplane centric. Applicants seeking airworthiness approval for rotorcraft can add appropriate guidance to tailor their application. This AC does not address Microwave Landing System (MLS).

Content
Cancels
Cancels
Number Title Date
120-29A Criteria for Approval of Category I and Category II Weather Minima for Approach

This AC provides an acceptable means, but not the only means, for obtaining and maintaining approval of CAT I & II Weather Minima including the installation and approval of associated aircraft systems.

 2002-08-12
120-28D Criteria for Approval of Category III Weather Minima for Takeoff, Landing, and Rollout

States an acceptable means, not the only means, for obtaining approval of Category III Landing Weather Minima and low visibility takeoff, including the installation and approval of associated aircraft systems.

 1999-07-13