What is DO-178C and why is it important for avionics software?

DO-178C (Software Considerations in Airborne Systems and Equipment Certification) is the standard for developing safety-critical avionics software. It defines processes and evidence required for certification based on Design Assurance Level (DAL): DAL A - Catastrophic failure condition (most stringent), DAL B - Hazardous, DAL C - Major, DAL D - Minor, and DAL E - No effect (minimal requirements). Key activities include: Requirements development, Design documentation, Coding standards, Testing coverage (structural, requirements-based), Configuration management, and Quality assurance. Higher DAL requires more rigorous verification and more independence between development and verification. DO-178C compliance is required for FAA/EASA certification.