<p>Power allocation is essential to maximise network throughput and minimise energy consumption and bit error rate performance. Thus, a new power allocation scheme for enhancing the performance of the air-based network, named Unmanned Aerial Vehicle (UAV) networks, is presented in this paper. The proposed power allocation allows the total power to be distributed optimally among the UAV network's nodes, including source relay and destination nodes. Then, energy consumption, transmission delay, and bit error rate in UAV networks are simultaneously enhanced. The typical UAV comprises three parts: remotely controllable flight platform (fixed wing or rotary wing), transmitter and receiver wireless nodes. In the proposed UAV networks, a wireless relay is fitted with a flight platform to extend network coverage and increase transmission throughput. The downside of mobile flight communication is the delay in data transmission caused by the UAV's movement. A consequence of this delay is increased total energy consumption, causing further degradation in bit error rate performance, especially at high <em>SNR</em> levels. Fortunately, delay and energy consumption can be traded off to improve communication performance in wireless communication. The proposed power allocation in this paper is achieved using the Scalarization optimisation method, which enables the best trade-off between energy consumption and data transmission delay and enhances the bit error rate. </p>