What is ELOS in Aviation? (Equivalent Level Of Safety)

In aviation, safety is of utmost importance. To ensure the safety of flights and passengers, various measures and standards are put in place. One such measure is the concept of Equivalent Level of Safety (ELOS). ELOS is a term used to assess and compare the safety levels of different aviation systems or operations. It helps aviation authorities and organizations determine if a new system or operation can match or exceed the safety performance of an existing system. Let’s delve deeper into the concept of ELOS and its significance in aviation safety.

The Importance of Equivalent Level of Safety (ELOS) in Aviation

Aviation is a highly regulated industry, and safety is at the core of its operations. The aim is to minimize the risks associated with flying and ensure that all systems and procedures align with the highest safety standards. ELOS plays a crucial role in achieving this goal. By evaluating the safety levels of different systems using a standardized approach, aviation authorities can make informed decisions regarding the approval, implementation, and improvement of aviation systems and operations.

When it comes to introducing new aircraft, technologies, or procedures in aviation, thorough safety assessments are necessary. The ELOS concept allows for a systematic evaluation of how the safety of the new system compares to that of existing systems. It helps answer the question, “Is the new system at least as safe as the current one?”

The concept of ELOS is particularly relevant when implementing changes or upgrades to existing aviation systems. By setting a baseline safety level, aviation authorities can ensure that any modifications or enhancements do not compromise safety. The ELOS approach provides a framework for assessing these changes and determining whether they improve safety or maintain an equivalent level of safety.

Additionally, ELOS allows for continuous safety improvement in aviation. By regularly evaluating the safety levels of systems and operations, aviation authorities can identify areas for improvement and implement necessary changes. This proactive approach helps prevent accidents and enhances the overall safety performance of the aviation industry.

The Assessment Process of Equivalent Level of Safety (ELOS)

Now that we understand the importance of ELOS in aviation safety, let’s explore the assessment process involved in determining the equivalent level of safety.

ELOS Framework

The assessment of ELOS involves a systematic framework that includes several key steps:

1. Hazard Identification: The first step in the ELOS assessment is to identify potential hazards associated with the aviation system or operation under consideration. Hazards may include equipment failure, human error, environmental factors, or any other condition that can adversely affect safety.

2. Risk Assessment: Once the hazards are identified, a comprehensive risk assessment is conducted. This involves analyzing the likelihood and severity of each identified hazard. The purpose is to determine the level of risk associated with the system or operation.

3. Safety Performance Indicators: Safety performance indicators are established to quantitatively measure the safety levels of systems or operations. These indicators could include metrics such as accident rates, incident rates, safety audits, or any other measure that reflects the safety performance of the aviation system.

4. Benchmarking: Benchmarking is a crucial step in the ELOS assessment process. It involves comparing the safety performance indicators of the new system or operation with that of existing systems or operations that are considered safe and have a proven track record. By doing so, aviation authorities can determine whether the new system meets or exceeds the safety levels set as a benchmark.

5. Decision Making: Based on the assessment results, a decision is made regarding the equivalent level of safety. If the new system or operation meets or exceeds the benchmark safety levels, it is considered to have achieved an equivalent level of safety. However, if the safety levels fall short, further improvements or modifications may be required before implementation.

Application of ELOS in Aviation

ELOS is a widely used concept in various aviation domains. It is applied to assess and compare safety levels in several areas:

1. Aircraft Certification: When a new aircraft model is developed, it undergoes a rigorous certification process. The concept of ELOS helps in determining whether the new aircraft meets the required safety standards and levels set by aviation authorities. It enables a systematic evaluation of the aircraft’s safety features, equipment, and operational procedures.

2. Air Traffic Management: ELOS is also applied in evaluating the safety of air traffic management systems and procedures. It helps determine the safety levels of communication systems, navigational aids, airspace design, and other components of air traffic management. By using ELOS, potential risks and hazards can be identified and mitigated, ensuring smooth and safe air traffic operations.

3. Airport Operations: The application of ELOS in airport operations involves assessing the safety levels of various airport facilities and procedures. This includes evaluating runway operations, taxiway management, ground handling processes, fire safety measures, and overall emergency preparedness. The aim is to ensure that airports meet the necessary safety standards to prevent accidents and incidents.

The application of ELOS in these areas and others allows aviation authorities to maintain a high level of safety across the industry. By comparing safety performance indicators and benchmarking against established standards, they can make informed decisions that prioritize safety in all aspects of aviation.


The concept of Equivalent Level of Safety (ELOS) plays a vital role in aviation safety. It allows aviation authorities and organizations to assess and compare the safety levels of different systems and operations. By using a systematic evaluation framework, ELOS helps determine if a new system or operation meets or exceeds established safety benchmarks. This approach ensures that safety is not compromised when introducing changes or upgrades in aviation. ELOS promotes continuous safety improvement and enables decision-makers to prioritize the well-being of passengers and aircraft. With ELOS, aviation remains one of the safest modes of transportation, setting high standards for the industry as a whole.

For More: What is GCAS in Aviation? (Ground Collision Avoidance System)