Development and Internal Validation of a Risk-Based Safe-Manning Framework for Wing-in-Ground Craft

Abstract

Purpose. This study developed and computationally verified a function-based method for determining core operational crew for wing-in-ground (WIG) craft.  Methods. A frozen 37-source corpus was mapped to six safety-critical functions, six mission phases, a competence matrix, and phase loads. Bounded integer compositions were tested using an exact scalar max-flow/min-cut model, 20% reserve, utilization caps, role-removal screening, and 10,000-trial simulation. Robustness analyses varied reserve and utilization, demand distributions, supporting competence coefficients (±20%), ten random seeds, and every present-role removal. Results. Baseline complements were three, four, five, and six crew for restricted Type A, coastal Type A passenger, demanding Type B, and remote Type C scenarios. In the primary triangular run, S1-S3 had no failures (Wilson 95% lower bound 99.962%); S4 had one (99.99%; 95% CI 99.943-99.998). The crew sequence persisted in 45/48 reserve-utilization cells and all coefficient perturbations. Across ten seeds, triangular feasibility was 100% for S1-S3 and 99.98%-100% for S4. Under lognormal-tail stress, ranges were 100%, 99.95%-100%, 99.68%-99.84%, and 96.94%-97.25% for S1-S4. No present-role removal was more favorable than the designated comparators. Conclusions. Concurrent transition/emergency workload, qualified takeover, fault management, and prolonged-survival capability should drive WIG manning. The 3-6-person outputs are internally consistent engineering baselines, not empirically validated or statutory minima; Type B/C tail sensitivity requires external validation.