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United States Department of Transportation United States Department of Transportation

Advisory Circulars (ACs)

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Advisory Circulars (ACs) search results
Number Title Status Office Date
90-50D Requirements for 760-Channel VHF Radio for Aeronautical Operations

Encourages aircraft owners to upgrade their air-ground radio communication systems. Describes and upgrades civil air traffic control frequencies in the very high frequency (118.000 to 136.975 MHz) band.

Active ASR-520 1992-04-09
90-67B Light Signals from the Control Tower for Ground Vehicles, Equipment, and Personnel

Provides the aviation community with the meaning of the light signals used when communicating with ground vehicles, equipment, and personnel on the airport movement area from the control tower.

Active ATP-129 1994-08-25
90-100A U.S Terminal and En Route Area Navigation (RNAV) Operations with Change 2

This advisory circular (AC) provides operational and airworthiness guidance for operation on U.S.

Active AFS-400 2007-03-01
90-101A Approval Guidance for Required Navigation Performance (RNP) Procedures with Authorization Required (AR) Including Change 1

This advisory circular (AC) provides airworthiness and operational approval guidance material for aircraft operators conducting Title 14 of the Code of Federal Regulations (14 CFR) part 97 Area Navigation (RNAV) Required Navigation Performance (RNP) instrument approach procedures (IAP) with Authorization Required (AR), charted as "RNAV (RNP) RWY XX.

Active AFS-400 2011-02-23
90-80C Approval of Offshore Standard Approach Procedures, Airborne Radar Approaches, and Helicopter En Route Descent Areas with Change 1

This AC provides criteria and describes acceptable methods for obtaining approval to use Offshore Standard Approach Procedures (OSAP), Airborne Radar Approaches (ARA), and Helicopter En Route Descent Areas (HEDA) to descend in uncontrolled airspace to an altitude where the pilot can proceed to land using visual references to the surface.

Active AFS-400 2017-12-21
90-95 Unanticipated Right Yaw in Helicopters

Examines the unanticipated right yaw phenomenon, the circumstances under which it may be encountered, how it can be prevented, and how the pilot should react if it is encountered.

Active AFS-800 1995-02-07
90-96A Approval of U.S. Operators and Aircraft to Operate Under Instrument Flight Rules (IFR) in European Airspace Designated for Basic Area Navigation (B-RNAV) and Precision Area Navigation (P-RNAV)

Provides guidance regarding on-board Area Navigation (BRNAV) equipment requirements for operators of U.S. registered civil aircraft, operating in a Basic Area Navigation (BRNAV) environment in the European region.

Active AFS-400 2005-01-13
90-102A Airspace Flow Program

This Advisory Circular replaces AC 90-102 and provides guidance to customers of the National Airspace System (NAS) regarding changes to the traffic management process for managing flights through a constrained area with an Airspace Flow Program (AFP).

Active AJR-1 2008-05-30
90-99 High Altitude Airspace Redesign Phase 1 Active ATA-301 2003-09-22
90-108 Use of suitable Area navigation (RNAV) system on Conventional Routes and Procedures - Change 1

This advisory circular (AC) provides operational and airworthiness guidance regrading the suitablity and use of RNAV systems while operating on or transitioning to, conventional i.e. non-RNAV, routes and procedures within the United States (US) National Airspace System (NAS).

Active AFS-400 2011-03-03
90-23G Aircraft Wake Turbulence

This advisory circular (AC) presents basic information on wake vortex behavior, alerts pilots to the hazards of aircraft wake turbulence, and recommends operational procedures to avoid wake turbulence encounters.

Active AFS-400 2014-02-10
90-91K North American Route Program

Provides guidance to users of the National Air Space System for participation in the North American Route Program (NRP).

Active AJR-1 2008-12-11
90-107 Guidance for Localizer Performance with Vertical Guidance and Localizer Performance without Vertical Guidance Approach Operations in the U.S.

This advisory circular (AC) provides guidance for operators to conduct Title 14 of the Code of Federal Regulations (14 CFR) part 97 instrument flight rules (IFR) Area Navigation (RNAV) Global Positioning System (GPS) instrument approach procedures (IAP) with Localizer Performance with Vertical guidance (LPV) and Localizer Performance without vertical guidance (LP) lines of minima using the wide area augmentation system (WAAS).

Active AFS-400 2011-02-11
90-115 Collaborative Trajectory Options Program (CTOP)

This Advisory Circular provides guidance to customers of the National Airspace System (NAS) regarding a new traffic management initiative for managing flights through a constrained area.

Active AJR-1 2014-06-24
90-109A Transition to Unfamiliar Aircraft

This advisory circular (AC) is intended to help plan the transition to any unfamiliar fixed-wing airplanes, including type-certificated (TC) and/or experimental airplanes.

Active AFS-800 2015-06-29
90-105A Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace

This advisory circular (AC) provides guidance for operators to conduct Required Navigation Performance (RNP) operations in the United States, in oceanic and remote continental airspace, and in foreign countries which adopt International Civil Aviation Organization (ICAO) standards for RNP operations.

Active AFS-400 2016-03-07
90-114B Automatic Dependent Surveillance-Broadcast Operations with Change 1

The intent of this AC is to facilitate operations using Automatic Dependent Surveillance-Broadcast (ADS-B) technology in compliance with Title 14 of the Code of Federal Regulations (14 CFR) part 91, §§ 91.225 and 91.227.

Active AFS-400 2019-12-30
90-93B Operating Procedures for Airport Traffic Control Towers (ATCT) that are not Operated by, or Under Contract with, the United States (Non-Federal)

This advisory circular (AC) recommends publications, administrative, and operational procedures that will assist in the management of a non-Federal ATCT (NFCT).

Active AJT-0 2013-04-22