Zero Trust principles for Unmanned Traffic Management (ZT-UTM) systems aim to establish a secure and resilient ecosystem for drone operations. In a UTM ecosystem, where drones interact with various stakeholders such as operators, airspace authorities, and other drones, vulnerabilities can arise from weak authentication, insecure communication protocols, or gaps in data integrity. ZT-UTM focuses on addressing these problem areas by implementing strict identity verification, continuous monitoring, and least-privilege access control for every interaction within the network. By identifying weaknesses, such as susceptibility to unauthorized access or data breaches, ZT-UTM enhances the system's robustness through advanced encryption, real-time threat detection, and secure data sharing frameworks. The approach not only ensures safe and reliable drone operations but also instills trust among ecosystem participants, paving the way for innovation and scalability in drone traffic management.