As next-generation wireless networks face increasing demands for massive connectivity, high reliability, and exceptional energy efficiency, the integration of Non-Orthogonal Multiple Access (NOMA) with Coordinated Direct and Relay Transmission (CDRT) has gained attention as a promising approach. This paper provides a detailed performance analysis of a NOMACDRT system incorporating Reconfigurable Intelligent Surfaces (RIS) and an UAV-mounted decode-and-forward relays, operating in a Rayleigh fading channel. The analysis targets scenarios where the direct communication path between the source and users is obstructed. The performance of the system, i.e. reliability (outage probability and ergodic capacity) and energy efficiency, is evaluated, considering the effects of the number of relays, RIS elements, and UAV positioning. Both analytical results and simulations reveal that increasing the number of relays and RIS elements, combined with optimal UAV positioning, significantly enhances the system performance.