Intro to the Avionics Regulatory Landscape: DO-178C and DO-254

Ensuring regulatory compliance for development in avionics is no simple task. There are many regulatory bodies, both international and local. Then there are the safety requirements, anti-terrorism measures, as well as environmental standards to adhere to. Add to that the complexity of crossing national borders, using a vast number of external suppliers, contractors, even payment processors, and you have yourself an incredibly complex environment to create software and hardware in. Continue reading to learn more about the regulatory landscape for aviation and defense, and for best practices you can apply to your approach to aviation compliance!


Modern aircraft are made up of millions of different parts and there are a huge number of agencies involved in regulating the industry to ensure safety. Since aviation and defense rely heavily on mission-critical applications, you would think that their development would be prioritized with equal emphasis. However, due to extreme cost reduction, which is a result of the fierce competition between national airlines and cheap carriers, maintaining quality at scale gets complicated, and fast.

That being said, airborne vehicles – whether intended for commercial or military use – must comply with functional safety standards so that they will fly safely from point A to point B. Safety and security are the most important factors for this industry and cannot be compromised despite cost-cutting measures; with passenger, crew, and operator lives at stake, they must always come first. So apart from checking out resources in SEBoK, the Guide to Systems Engineering Body of Knowledge, where should you start learning about regulatory compliance for this industry?

We’ve got you covered. Read on for an introduction to the main standards developers of IT products for airborne vehicles need to adhere to, as well as key best practices for meeting them.

The Basics of DO-178C and DO-254

DO-178C: Software Considerations in Airborne Systems and Equipment Certification

The DO-178C is the definitive standard for commercial avionics software development which is used both in the aerospace and defense industries. Approved since 2013, it describes guidelines for producing airborne systems and equipment software.

Meeting these recommendations is the primary way to achieve airworthiness and get software approved for use. In other words, complying with the DO-178C is vital; without it, you literally won’t be allowed to take off.

The DO-178C classifies safety using five different levels, each one relating to the gravity of what happens if the software fails in this case.

  • Level A: Catastrophic
  • Level B: Hazardous
  • Level C: Major
  • Level D: Minor
  • Level E: No Safety Effect

The five levels are assigned based on the risk present; the higher the risk, the more safety standards need to be complied with, and the more strenuous it will be to demonstrate and prove compliance.

Learn more about key aviation standards:

DO-178C and DO-254 Explained

Complying with the DO-178C requires putting emphasis on the following:

  • Gathering requirements and planning
  • Traceable development through all stages
  • Verification process which helps prove you’ve satisfied compliance

If you’re thinking of looking for a tool to help you and your team achieve compliance at a lower cost, keep an eye out for solutions that offer thorough test coverage (if the tests can be created directly from the outlined requirements, even better), traceability at all stages of development, and comprehensive quality assurance.

Design Assurance Guidance for Airborne Electronic Hardware (aka DO-254)

The DO-254 is commonly referred to as the “DO-178’s Little Sibling”. However, the idea that this guideline is simpler than its counterpart is misleading, as it can prove equally complex to meet its requirements. Formally recognized in 2004, the DO-254 was created as a response to the fact that firmware began playing a larger role in avionics.

At the time, firmware development in avionics was still unregulated and certification took place too late in the process. The purpose of this standard was to remedy that gap and ensure a high level of safety in airborne electronic systems, so that not only can it be successfully verified, but also meet the initial requirements set out in early stages of product design. Finally, it ensures that you have the right information for certification right from the start, through validation processes.

Similarly to the DO-178C, the DO-254 standard outlines five different levels of compliance, also referred to as Design Assurance Levels or ‘DALS’. The level of compliance needed depends on the amount of harm a hardware failure would cause. The range of the 5 levels from A-E starts from the most severe, in which a hardware failure would cause a catastrophic disaster for the aircraft, and ends with the least impactful, where a hardware failure would not have any impact on the aircraft’s safety or performance at all. This standard, on top of what the DO-178C emphasizes, also stresses a focus on the verification process and tool assessment.

Learn more:

ALM for Aviation & Defense Systems Development

Must-knows about the product certification process

When a manufacturer designs a new aircraft and all the software and hardware that goes along with it, it must undergo a lengthy and costly certification process to be authorized to fly. Being prepared for the certification process is more crucial than ever as certification delays can cost millions and be the deciding factor in a program’s profitability.

First, new aircrafts need to be submitted to the relevant regulatory authorities to receive a test certificate. The FAA (Federal Aviation Administration) is the appropriate body in the US, while the EASA (European Safety Agency) is its EU counterpart. A test certificate indicates how airworthy an aircraft is according to the submitted manufacturing design, as well as showing that it is intended for serial production and therefore compliant with applicable standards.

Once the test certificate is issued, extensive testing kicks off, first in simulators, next on the airframe structure, and as a final step, up in the air. In order to do this, manufacturers must build several prototype models which are just used for testing. Once the structural tests are carried out, actual in-air flight tests can start, including test flights in other locations to evaluate performance at extreme temperatures and altitudes.

Finally, an airworthiness certificate is produced for the aircraft which confirms that it is ready to fly.

Looking for an Aviation product engineering tool to support compliance? Check out Intland's DO-178C Template for codebeamer X:

Intland's DO-178C Template for Avionics Systems Engineering

The easiest way to cut down on compliance time and costs

Developing software and hardware for airborne vehicles is an arduous task with thousands of moving parts and a myriad of regulations to satisfy. With so many standards and regulations, how can the manufacturers of technology for aviation and defense achieve compliance?

An easy way to streamline the development of airborne products, aviation software, and embedded avionics systems is by using an Engineering Lifecycle Management platform like codebeamer X. Cut development and compliance costs, reduce cycle times, and achieve compliance with DO-178C, DO-254, ARP4754A, and other aviation standards.

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