The purpose of this document is to provide operational guidance for key life-cycle management, which refers to the phases through which digital certificates and associated cryptographic keys progress, from creation through usage to retirement. Additionally, this document provides implementation guidance for online certificate provisioning of aircraft systems. The scope includes both the onboard part (aircraft system) as well as the ground part (PKI provider and Ground Infrastructure). Consideration of both onboard and ground provides the benefit of security considerations being included in the process flow and chain of custody. Specifically, the management to and from the aircraft is defined within a workflow.