This SAE Aerospace Recommended Practice (ARP) provides recommendations for the development of aircraft and systems, taking into account aircraft functions and operating environment. It provides practices for ensuring the safety of the overall aircraft design, showing compliance with regulations, and assisting a company in developing and meeting its own internal standards. These practices include validation of requirements and verification of the design implementation for safety, certification, and product assurance. The guidelines in this document were developed in the context of U.S. Title 14 Code of Federal Regulations (14 CFR) Part 25 and European Union Aviation Safety Agency (EASA) Certification Specification (CS) CS-25. They may be applicable in the context of other regulations, such as 14 CFR Parts 23, 27, 29, 33, and 35, and CS-23, CS-27, CS-29, CS-E, and CS-P. This document addresses the development cycle for aircraft and systems that implement aircraft and system functions. It does not include detailed information on the following subjects and references:

• Software development; refer to RTCA DO-178C/EUROCAE ED-12C.
• Electronic hardware development; refer to RTCA DO-254/EUROCAE ED-80.
• Integrated modular avionics development; refer to RTCA DO-297/EUROCAE ED-124.
• Airworthiness security process; refer to RTCA DO-326A/EUROCAE ED-202A.
• Safety assessment processes; refer to ARP4761A/EUROCAE ED-135.
• A process for accomplishing in-service safety assessment is described in ARP5150A and ARP5151A or in other documents such as the guidance material of EASA Part 21 (GM21) when required by applicable regulation. In this document, wherever references to ARP5150A/ARP5151A are made, the reader should understand this also implies EASA Part 21 (GM21).
• Master Minimum Equipment List (MMEL) or Configuration Deviation List (CDL) development; refer to applicable regulatory guidance from the applicable Certification Authority.
• Aircraft structure and aerodynamics development.

Figure 1 outlines the relationships between the various development documents, which provide guidelines for safety assessment, electronic hardware and software life cycle processes, and the system development process described herein.