DO 178B vs DO 178C Training: What’s the Difference?

Aerospace is a complex subject. When you add software to the equation, it gets even more confusing.

On top of both of these complex systems, there are two different training systems called DO-178B and DO-178C. It sounds like we’re in a Stanley Kubrick film. Somebody, please send a computer to explain all of this. 

Good news: The computer responded. It’s going to help demystify this wonderous labyrinth.

What’s the difference between DO-178B vs. DO-178C training? Continue reading to find out. 

What Is DO-178B and DO-178C Training?

DO-178B and DO-178C are new aerospace systems software development guidelines. These training programs guide companies and individuals developing avionics software. 

The training programs verify the safety and compliance protocols for aerospace software programs. Most national guidelines require all new systems to follow DO-178C or its international equivalents.

The majority of the changes from DO-178B to DO-178C are minor. However, all of these changes are important.

The Aerospace Software industry is accustomed to these sorts of changes. But to stay at the top of their game, companies have to continue to adapt. 

Aerospace Software companies must stay informed on all the current guidelines and safety regulations for their products’ approval and distribution. 

Small But Important Changes in DO-178C Training 

DO-178C is a refined version of DO-178B. But companies transitioning from DO-178B to DO-178 C have encountered many snags. There are critical differences between the two training programs software companies must understand for a smooth transition.

In particular, DO-178C expands upon the concept and fulfillment of Development Assurance Level (DAL) A, B, C, and D.

DO-178B vs. DO-178C

SC-205 (Special Committee 205) created DO-178C to revise and update DO-178B. SC-205’s revisions addressed current software development and verification technology changes in the industry.

Most of these adaptations pertain to the Software Level (DAL). The Software Level is a hazard analysis rating system.

This rating system classifies the software’s failure using a five-part system. The rating of a DAL is either Catastrophic, Hazardous, Major, Minor, or No Effect.

For example, if a company uses a piece of software for its airplane, and a particular component fails mid-flight, the DAL describes the severity level of the failure. 

  • Catastrophic– The failure may cause a crash.
  • Hazardous– The failure has a substantial negative impact on the system.
  • Major– The failure is less than Hazardous (for example, the fault causes minor disturbances to passengers instead of injuries).
  • Minor– A failure less than Major (for example, passengers experience a minor inconvenience during the flight).
  • No effect– The DAL has no impact on safety, aircraft operation, or crew workload. 

By studying these descriptions, you can see some of the vaguery DO-178 C tried to define.   

DO-178B Gaps and Clarifications

Many of DO-178C’s changes were minor clarifications, such as changing the wording in one or two paragraphs.

However, these changes might stick out to those who are familiar with DO-178B. DO-178C training addresses these gaps and offers clear guidance to applicants. These gaps are no longer subject to interpretation; they have precise definitions. 

DO-178B Topic Omissions

DO-178C training omits a few general topics DO-178B training discussed. The deleted DO-178C topics include the oversight of suppliers, Parameter Data Items (PDIs), and traceability. 

Objectives and Activities

DO-178C restructured the objectives of DO-178B. DO-178B failed to show how each activity pertained to the training objective.

Activities are a major focal point of the training. For example, Section 1.4 titled, “How to Use This Document,” instructs the trainee in precise terms.

With DO-178C training, the trainee understands why they have to master each activity and how each activity pertains to the whole.  

DO-178C Changes 

DO-178C Refined many of DO-178B’s imprecise descriptions. Compared to DO-189 B, DO-178C has clear explanations and straightforward language.

DO-178B had cluttering jargon, which clouded its technology descriptions. Phrases such as, “including, but not limited to, “guidance,” “purpose,” “goals,” and “objective” were vague and indirect. DO-178C clarified these terms in its glossary.

DO-178C cleared the inconsistencies from DO-178B Annex A. Most of these inconsistencies pertained to DAL A. DO-178 clarified the objectives for DAL A, B, and C. 

DO-178C explicitly explains specific Software Configuration Management issues DO-178B failed to clarify.  

DO-178C’s Most Important Change

DO-178C’s most crucial innovation was streamlining its supplemental guidance documents. DO-178C training also optimized DO-178B’s approval process. 

Effects on Software Development

DO-178C has exceeded expectations. DO-178C training clarified DO-178B’s vagueness and incongruity. Because it was confusing, avionics professionals struggled and often spent more money on certification. 

With DO-178C, avionics professionals know where they’re flying. Professionals understand the expectations and how each aspect of training relates to the profession. 

DO-178C makes avionics software certification a cost-effective guidance tool for any avionics professional. 

How DO-178C Training Expands the Avionics Software Industry 

Now that DO-178C training is the aviation industry standard, it also provides recommendations for the production of avionics software. DO-178C training guidelines define software considerations in airborne systems. 

The training gives clear-cut recommendations for software production in compliance with safety and airworthiness requirements. First published in 2011, DO-178C training continues to expand software-aircraft integration. 

The training creates more direct connections with software and avionics and avionics professionals immediately notice the difference. The changes made from DO-178B to DO-178C have also made avionics-software training more inviting on the international scale.

DO-178C has seen increased demand, particularly outside of the US, where DO-178B failed to reach. Guidelines and training protocols for avionics software are in high order in these companies as they continue to try and build new aircraft programs. 

How to Keep Adding to DO-178C 

DO-178C trainees made avionics software training more accessible than DO-178B. But there’s still work to be done. To expand and standardize the avionics software industry, the training must clearly articulate its objectives and directives. 

Avionics software combines two of the most esoteric subjects on the planet. The challenge is communicating these guidelines effectively, so trainees feel confident in their particular field.

Read more blogs to discover how the world’s businesses continuously adapt to a changing environment.