Navigation & Flight Systems

AC 90-114C – ADS-B Operations
Automatic Dependent Surveillance–Broadcast (ADS-B) is a critical component of modern air traffic management. This AC provides guidance on equipping and using ADS-B for improved situational awareness and compliance with FAA regulations. It ensures accurate tracking and navigation capabilities, enhancing safety and efficiency in controlled airspace.

AC 20-140C – Data Communications in NAS
This circular provides guidance on the integration of data communications in aircraft for improved navigation and air traffic management. It details how pilots and operators can use digital messaging systems to streamline flight operations and enhance situational awareness.

AC 20-172B – Avionics for Performance-Based Navigation
Performance-Based Navigation (PBN) improves accuracy and efficiency in modern flight operations. This AC provides guidance on the selection and approval of avionics equipment necessary for complying with PBN requirements, ensuring aircraft can safely navigate with minimal reliance on ground-based navigation aids.

AC 120-70C – Use of Flight Management Systems
This circular provides guidance on the use of Flight Management Systems (FMS) for enhanced navigation and operational efficiency. It covers the integration of FMS with avionics to ensure accurate routing and compliance with required navigation performance (RNP) criteria.

AC 20-170 – Integrated Navigation Systems
Integrated navigation systems combine GPS, inertial navigation, and other avionics to enhance situational awareness. This AC provides guidance on system approval and operational requirements to maintain accuracy and reliability during flight.

AC 20-171 – Navigation System Redundancy
This circular discusses redundancy in avionics navigation systems to ensure continuous operation in case of primary system failure. It provides recommendations for backup systems and cross-checking capabilities to improve flight safety.

Communication & Data Systems

AC 20-133 – Cockpit Display of Traffic Information (CDTI)
CDTI systems enhance situational awareness by providing real-time traffic information directly in the cockpit. This guidance helps operators integrate CDTI with existing avionics to improve collision avoidance and in-flight decision-making.

AC 20-151C – Radio Frequency Identification (RFID) Usage
RFID technology is used to track and manage avionics components efficiently. This AC provides guidelines on integrating RFID into aircraft maintenance and operations to streamline inspections and improve inventory accuracy.

AC 20-163 – Data Link Communication Systems
This AC provides guidance on integrating data link communication systems for real-time information exchange between aircraft and air traffic control. It ensures interoperability with existing avionics infrastructure.

AC 20-164A – Digital Flight Data Recorders
Digital Flight Data Recorders (DFDRs) play a crucial role in accident investigations and safety monitoring. This AC outlines avionics certification standards for data recording systems and their interface with aircraft systems.

Weather & Environmental Systems

AC 91-75 – Flight Planning & Weather Considerations
Proper weather assessment is critical for safe flight operations. This AC provides guidance on how avionics systems assist pilots in pre-flight planning and enroute weather monitoring, reducing risks associated with adverse weather conditions.

AC 91-44A CHG 1 – Aircraft Fuel Systems & Handling
Avionics play a role in fuel management by providing accurate fuel monitoring and alerting pilots of potential issues. This circular offers guidance on fuel system design and best practices for handling and monitoring fuel levels in flight.

AC 20-186A – Lightning & Environmental Protection for Avionics
Lightning strikes and environmental factors can impact avionics performance. This AC provides guidance on designing and testing avionics systems to withstand environmental stresses and maintain operational reliability.

Flight Displays & Instrumentation

AC 23.1311-1C – Electronic Displays in Part 23 Aircraft
The evolution from analog to electronic flight displays requires careful integration with existing avionics systems. This AC provides recommendations on selecting and certifying electronic flight displays to improve situational awareness and operational efficiency.

AC 20-131A – Head-Up Display (HUD) Systems
HUD systems improve pilot awareness by displaying critical flight information within their field of view. This circular outlines certification requirements for HUD installations and how they enhance safety during complex flight operations.

AC 20-141B CHG 1 – Avionics Fire Protection
This AC addresses fire protection considerations for avionics components, including cockpit displays and electronic instruments. It provides testing criteria to ensure safety and compliance with FAA regulations.

AC 20-156 – Avionics System Safety Assessment
Avionics system safety is crucial for operational reliability. This AC outlines the processes for risk assessment, failure analysis, and ensuring compliance with FAA safety standards.

AC 20-157 – Human Factors in Avionics Design
This circular highlights the importance of human factors in avionics design. It covers cockpit layout, display readability, and workload management to optimize pilot interaction with avionics systems.

Maintenance & Avionics Testing

AC 20-181 – Maintenance Procedures for Avionics
Proper maintenance ensures avionics longevity and reliability. This AC provides best practices for troubleshooting, repairing, and inspecting avionics systems in accordance with FAA regulations.

AC 20-182A – Calibration and Testing of Avionics Equipment
Avionics components require periodic calibration and testing to maintain accuracy. This AC explains how to conduct proper calibration procedures and ensure equipment meets performance standards.

AC 20-183 – Integration of Avionics Upgrades
As aircraft avionics evolve, integrating new systems into legacy aircraft presents challenges. This AC provides guidance on upgrading avionics without compromising system integrity or safety.

AC 20-184 – Avionics Hardware & Reliability Standards
Hardware reliability is crucial for avionics performance. This AC discusses testing procedures and failure prevention measures to ensure avionics equipment meets operational standards.

AC 43-14 – Maintenance for Avionics Equipment
Avionics maintenance is critical for ensuring long-term functionality and safety. This AC provides best practices for inspecting, troubleshooting, and repairing avionics systems to meet FAA compliance standards.

AC 43-15 – Avionics Wiring & Soldering Techniques
Proper wiring and soldering are essential for avionics reliability. This AC provides guidance on industry best practices for wiring and connections in aircraft avionics systems.

AC 43-206 CHG 1 – Aircraft Corrosion Control
Corrosion can severely impact avionics components and overall aircraft integrity. This AC explains how operators can identify, treat, and prevent corrosion in avionics and electrical systems to extend the life of their equipment.

AC 43-215 Ed Update 3 – Composite Aircraft Structural Repair
Avionics systems are often embedded in aircraft structures, especially in composite airframes. This AC provides guidance on repairing and maintaining composite structures to ensure continued avionics functionality.

AC 43-216A – Calibration of Avionics Testing Equipment
Calibration ensures that avionics testing tools provide accurate measurements. This AC discusses procedures for maintaining precision in avionics diagnostic equipment.

AC 43-218 – Avionics System Troubleshooting Techniques
Effective troubleshooting is crucial for avionics maintenance. This AC provides strategies for diagnosing and resolving avionics system issues efficiently.

Airworthiness & Certification of Avionics

AC 20-150B – Aircraft Certification: Technical Standard Orders
This AC provides guidance on the certification of avionics equipment under Technical Standard Orders (TSOs). It ensures that avionics components meet stringent FAA requirements before installation in aircraft.

AC 20-152A – Approval of Integrated Avionics Systems
Integrated avionics systems combine multiple functions such as navigation, communication, and surveillance. This AC explains how these systems should be designed and tested for FAA approval.

AC 20-165B – Certification of Avionics Systems
This AC provides comprehensive guidance on the certification process for new avionics systems. It includes requirements for design, testing, and regulatory approval to ensure compliance with FAA airworthiness standards.

AC 20-167A – Software Development for Avionics
Avionics software must meet stringent reliability standards. This AC details the processes for developing, testing, and certifying software used in aircraft avionics systems.

AC 20-177 – Cybersecurity in Avionics
With increasing connectivity, avionics systems are vulnerable to cyber threats. This AC outlines security measures to protect avionics software and hardware from unauthorized access and cyberattacks.

AC 20-185A – Software Approval for Avionics Systems
Software plays a critical role in modern avionics, from autopilot systems to electronic displays. This AC provides guidance on developing, testing, and certifying software for aviation use.

AC 20-68B – Protection of Electrical & Avionics Components
Electrical faults can cause avionics failures. This AC covers best practices for wiring, shielding, and protecting avionics components from electrical disturbances.

AC 23-18 – Avionics Standards for Small Aircraft
Small aircraft avionics have unique design and operational considerations. This AC provides guidance on selecting and certifying avionics systems for small aircraft to ensure compliance with FAA Part 23 regulations.

AC 23-23 – Avionics System Performance for Small Aircraft
This AC outlines performance standards for avionics systems in small aircraft, including requirements for displays, navigation, and communication systems

Electronic Devices & Flight Operations

AC 91.21-1D Ed Update – Portable Electronic Devices (PEDs) Use on Aircraft
This AC outlines regulations and safety considerations for using portable electronic devices (PEDs) onboard aircraft. It provides insight into potential interference with avionics and how operators can mitigate risks while allowing safe PED use.

AC 90-50D – Requirements for Aircraft Operations in Controlled Airspace
Proper avionics configurations are necessary for operations in controlled airspace. This AC details equipment and operational requirements for pilots navigating high-traffic areas.

AC 119-2A – Air Carrier Operations Safety Management
This advisory circular provides guidance for safety management systems (SMS) in air carrier operations. It outlines best practices for integrating avionics monitoring, data collection, and operational risk assessment tools to enhance flight safety and compliance with FAA regulations.

The Role of FAA Advisory Circulars in Avionics Integration

FAA Advisory Circulars (ACs) provide essential guidance on the certification, operation, and maintenance of avionics systems, ensuring that aircraft function safely and efficiently. These documents cover a range of avionics topics, including navigation (AC 20-170, AC 20-171), flight management (AC 120-70C), system redundancy, and safety management (AC 119-2A). The interplay between these ACs ensures that avionics systems meet stringent regulatory and operational standards while evolving to keep up with advancements in technology. However, since different ACs are issued at different times and sometimes address overlapping concerns, conflicts can arise in the way avionics are implemented, maintained, or upgraded.

To successfully implement avionics systems in compliance with FAA guidance, aviation professionals must recognize that ACs are not strict regulations but rather recommendations that sometimes evolve and contradict earlier guidance. The interplay between these circulars requires operators, engineers, and regulatory bodies to assess the specific needs of an aircraft and determine the most suitable application of the guidance provided. Cross-referencing ACs, engaging with avionics manufacturers, and considering real-world operational constraints are key to ensuring compliance while maximizing system performance. Ultimately, these advisory circulars work together to create a framework for safety, efficiency, and technological advancement, even when contradictions require careful reconciliation.