Editing Avionics software (section)

==Regulatory issues==
Due to safety requirements, most nations regulate avionics, or at least adopt standards in use by a group of allies or a customs union.  The three regulatory organizations that most affect international aviation development are the U.S, the E.U. and Russia.

In the [[United States|U.S.]], avionic and other aircraft components have safety and reliability standards mandated by the Federal Aviation Regulations, Part 25 for Transport Airplanes, Part 23 for Small Airplanes, and Parts 27 and 29 for Rotorcraft.  These standards are enforced by "designated engineering representatives" of the [[Federal Aviation Administration|FAA]] who are usually paid by a manufacturer and certified by the FAA.

In the [[European Union]] the [[International Electrotechnical Commission|IEC]] describes "recommended" requirements for safety-critical systems, which are usually adopted without change by governments.  A safe, reliable piece of avionics has a "CE Mark."  The regulatory arrangement is remarkably similar to fire safety in the U.S. and Canada.  The government certifies testing laboratories, and the laboratories certify both manufactured items and organizations.  Essentially, the oversight of the engineering is outsourced from the government and manufacturer to the testing laboratory.

To assure safety and reliability, national regulatory authorities (e.g. the [[FAA]], [[Civil Aeronautics Administration (United States)|CAA]], or [[United States Department of Defense|DOD]]) require software development standards.  Some representative standards include [[MIL-STD-2167]] for military systems, or RTCA [[DO-178B]] and its successor [[DO-178C]] for civil aircraft.

The regulatory requirements for this software can be expensive compared to other software, but they are usually the minimum that is required to produce the necessary safety.