Internet connectivity which was in experimental stages only a few years ago is a reality today. Current implementations allow passengers to access Internet for pleasure and in some cases secure VPN access is provided to corporate networks. Several researchers are looking at the possibility of the existence of a total of three networks: passenger network (PN); crew network (CRN); and the control network (CON). Researchers envision an architecture where these three networks will co-exist in an airplane. The available Internet connectivity can be utilized for transporting flight critical information like cockpit flight data recorder (CFDR) data, digital flight data recorder (DFDR) data, cockpit voice recorder (CVR) data, and controller pilot data link communication. In addition, the internet connectivity could also be used for other safety mechanisms like video surveillance and remote control of the flight. Security is one of the major concerns that affect the successful deployment of Aircraft Data Networks (ADN) and other safety features. Several studies have been carried out to secure the network using fJl"ewalls and intrusion detection system but so far no study has focused on securing the communication channel (between the aircraft and the gronnd station) and its impact on the ADN. The scope of this research is to determine the v iability and need of a security mechanism. The research will also focus on the performance of different security architectures and determine their usability in the framework of an ADN.