High-tech companies are investing in drone technologies for urban air delivery to address last-mile delivery issues and reduce road traffic congestion. Effective traffic management is crucial for scaling up these services in dense urban environments. This paper introduces a tube-based ConOps route network planning method, which decouples the NP-hard network planning problem into single-path problems and uses a space cost function for dense route design. Tests show this method generates near-optimal routes with significant computational time savings.