As the number of unmanned aerial vehicle (UAV) operations is growing rapidly, the risk of collisions increases significantly, making the coordination and verification of flight path compliance crucial. Since many different stakeholders, such as different UAV service suppliers (USS) and UAV operators are involved in an advanced air mobility (AAM) system, the system shall be decentralized and telemetry data shall be measured by the local community using sensor devices. In order to increase system resilience, sub-components of the system are implemented on a blockchain. Smart contracts are used to check whether a UAV has actually navigated the route specified by the USS pre-flight. Due to the restrictions of the system, the flight plan cannot be publicly revealed. Zero-Knowledge proofs (ZKPs) are unfeasible for this use case due to the high number of transactions and computational effort. Therefore, a novel approach has been developed that crosschecks measured telemetry data of UAV flights with flight plans and verifies the correctness without revealing any sensitive flight information. The verification results of UAV telemetry data can further be used to reward UAV operators for complying with the planned flight path.