Dayton Aerospace recently presented Airworthiness Risk and MIL-HDBK-516C at the 2018 Aircraft Airworthiness & Sustainment (AA&S) Conference held April 23-26 in Jacksonville, FL. Authored by airworthiness experts, Colonel Wayne Johnson, US Air Force (USAF) (Ret), and Ms. Dawn McGarvey-Buchwalder, former USAF Airworthiness Office branch chief, the presentation discussed lessons learned during industry participation in the USAF airworthiness certification process, with a specific focus on risk and how it is handled during that process. Based on first-hand experience with both government and industry during specific certification efforts, this briefing provided insight into how the USAF deals with risk and discussed how industry partners can facilitate success by providing pertinent and timely airworthiness products—enabling the USAF to efficiently issue the required flight authorizations and allowing industry to remain on schedule with reduced manpower.
Governed by MIL-STD-882E, system safety is a “global” process impacting all aspects of air system development. The Department of Defense (DOD) drives design toward zero mishaps with the ultimate goal of designing systems that contain no hazards; however, risk is largely unavoidable due to limits in resources, schedule and funding. It is very rare that any air vehicle system will be completely compliant with all MIL-HDBK-516C criteria, therefore residual risks remain. Higher levels of risk may be tolerable as long as the risks are well understood and accepted by an appropriate authority. As such, a more realistic goal is to design inherently safe aircraft with the minimum safety-imposed operational restrictions. To this end, the military works to prevent the initial creation of hazards and then manages any residual hazards.
In the USAF, there are two different risk-related processes: 1) System safety risk acceptance through the program office approval chain of command, and 2) an airworthiness review accomplished by an independent Technical Airworthiness Authority (TAA) assessment. The TAA assessment, governed by AWB-150A, Airworthiness Risk Assessment and Acceptance, is an aggregate of all airworthiness criteria for the system including the applicable system safety assessment.
In proposals and during program execution after contract award, industry plays a key role in providing products to the government program office that are essential for military certification and risk acceptance. When industry understands MIL-HDBK-516C content and the government’s expectations for artifact presentation, the success of the certification effort will be maximized.