What is DO-178B? DO-178B defines the guidelines for development of aviation software in the USA.

DO-178B has become a de facto standard. Produced by Radio Technical Commission for Aeronautics, Inc. (RTCA), the FAA's Advisory Circular AC20-115B established DO-178B as the accepted means of certifying all new aviation software.

DO-178B is primarily concerned with development processes. As a result, certification to DO-178B requires delivery of multiple supporting documents and records. The quantity of items needed for DO-178B certification, and the amount of information that they must contain, is determined by the level of certification being sought.

The targeted DO-178B certification level is either A, B, C, D, or E. Correspondingly, these DO-178B levels describe the consequences of a potential failure of the software: catastrophic, hazardous-severe, major, minor, or no-effect.

The DO-178B certification process is most demanding at higher levels. A product certified to DO-178B level A would have the largest potential market, but it would require thorough, labor-intensive preparation of most of the items on the DO-178B support list.

Conversely, a product certifying to DO-178B level E would require fewer support items and be less taxing on company resources. Unfortunately, the product would have a smaller range of applicability than if certified at a higher level.