What is AC in Aviation? (Advisory Circular)

Aviation is a complex and highly regulated industry, with safety being a paramount concern. In order to ensure safe operations and adherence to industry standards, regulatory bodies issue various guidelines and documents for the aviation community to follow. One important document that plays a significant role in aviation is the Advisory Circular (AC). In this article, we will explore what an Advisory Circular is, its purpose, and its significance in the field of aviation.

What is an Advisory Circular (AC)?

An Advisory Circular (AC), as the name suggests, is a type of advisory document provided by regulatory agencies to assist the aviation community in understanding and complying with the regulations and standards set forth by those agencies. It is a non-binding document that offers guidance, interpretation, and clarification on a wide range of aviation-related topics. While not legally binding, an AC is highly influential and serves as a valuable resource for pilots, operators, and other aviation professionals.

Advisory Circulars are typically issued by national aviation authorities or regulatory bodies, such as the Federal Aviation Administration (FAA) in the United States or the European Aviation Safety Agency (EASA) in Europe. These documents are designed to supplement existing regulations and provide additional information and guidance to ensure safe and efficient operations within the aviation industry.

Importance of Advisory Circulars in Aviation

Advisory Circulars hold significant importance in the aviation industry due to their ability to provide vital guidance and interpretation of regulatory requirements. Let’s take a closer look at why ACs are so important:

Enhancing Safety

Safety is the number one priority in aviation, and Advisory Circulars play a crucial role in enhancing safety levels within the industry. These documents provide detailed guidance on specific topics, such as maintenance procedures, pilot training, airport operations, and airspace management. By following the guidelines outlined in ACs, aviation professionals can ensure that they are operating in a safe and compliant manner, minimizing the risk of accidents and incidents.

For example, the FAA’s Advisory Circular 120-12A provides guidance on various aircraft maintenance topics, including inspection techniques and procedures. By following the recommendations outlined in this AC, maintenance personnel can ensure that aircraft are maintained to the highest standards, reducing the likelihood of mechanical failures or malfunctions during flight.

Standardization and Consistency

The aviation industry operates on a global scale, with flights crossing international boundaries every day. To ensure standardization and consistency in operations, it is crucial to have universally accepted guidelines and practices. Advisory Circulars help achieve this goal by providing consistent guidance that can be followed by aviation professionals worldwide.

For instance, AC-120-36E issued by the FAA offers guidance on security awareness training programs for flight crew members. This advisory circular ensures that all flight crew members and operators follow a standardized approach to security training, regardless of their location or the airline they work for. Such standardization helps create a more cohesive and efficient aviation system.

Clarification and Interpretation of Regulations

Regulations within the aviation industry can sometimes be complex and challenging to interpret. Advisory Circulars provide valuable clarification and interpretation of these regulations, helping aviation professionals understand their responsibilities and obligations.

For example, AC-91-57A issued by the FAA offers guidance on the use of handheld laser pointers near airports. This advisory circular clarifies the regulations surrounding laser pointer usage and highlights the potential risks they pose to aviation safety. By providing clear guidance, the AC helps pilots and the general public understand the regulations and take appropriate measures to mitigate risks.


Advisory Circulars are an essential component of the aviation regulatory framework. They play a vital role in enhancing safety, promoting standardization, and providing clarity on regulatory requirements within the industry. While not legally binding, ACs provide valuable guidance and interpretation that help aviation professionals operate in a safe and compliant manner. It is essential for pilots, operators, and other aviation personnel to stay updated with the latest Advisory Circulars relevant to their operations to ensure safe and efficient practices.

For More: What is LAT in Aviation? (Large Air Tanker)