Assessing Service Feasibility in eVTOL Cargo Networks: Time Discretization, Battery Carryover and Fleet Restoration

Time discretization can change whether fixed eVTOL cargo resources admit full service. We combine pooled time–energy exclusion bounds, a sufficient grid-step threshold and independently verified schedules under matched return and battery-restoration conditions. The main bound covers single-origin direct deliveries with depot charging and specified symmetric route resources. A 13-hub Shenzhen scenario uses synthetic demand and an analytical aircraft. Over 32 h, its 15 min grid requires 65.5 aircraft-hours against 64 available, whereas a verified 3 min schedule delivers 25.2 t with zero backlog at every window boundary and restores both aircraft. Coarse-grid exclusions paired with fine-grid witnesses recur in 12 of 27 sensitivity cases, ten of 21 energy/resource settings and two of nine synthetic layouts. Additional comparisons retain linked parameters from two published electric-aircraft concepts across 120 grid–instance arms and a matched 10% energy stress. Four cases for the larger concept retain a 15-to-3 min feasibility contrast in both suites; none is confirmed for the smaller concept. All 96 accepted schedules pass independent nonlinear replay. Published mission-energy and manufacturer-specification checks quantify reduced-model discrepancies without establishing operational validation. The results support instance-specific grid assessment; passing a resource screen alone does not establish service feasibility.