The information technology (IT) revolution, combined with people's need to access information quickly, has resulted in the explosive growth of the Internet in the past decade. Ubiquitous access to the Internet has become an essential component of a mobile workforce and multiple mechanisms are being devised to ensure seamless connectivity to corporate resources. An integrated security framework requires a careful consideration of the security features of the network within an airplane. Potentially, the aircraft could consist of three kinds of networks namely passenger network, crew network, and control network. The security protocol implemented must ensure a proper separation of these networks and also watch for any security protocol violations. In this paper, the authors review the existing aircraft data network standards, security provisioning, and the security threats associated with the aircraft data networks. In addition, the authors also analyze the security threats associated with different network architectures.