In this Federal Aviation Administration (FAA) funded project, we analyze the data link security with threat modeling and develop a simulation testbed with a risk assessment tool prototype. We perform simulated tests of identified threats to determine an optimal tool/solution to protect against potential aviation data link security threats. Within the scope of the task, we will build a testbed environment to replicate critical wireless data links and collect real data imitating the identified threats of a potential hacker. Based on this testbed data collection and in conjunction with their reviewing capabilities and specifications of existing security assessment tools, we will develop a requirements/specification document for an effective security assessment tool. We will work on designing and building a prototype FAA security risk assessment tool using existing commercial and/or open source tools to test each threat scenario identified during the data collection phase.