Humanitarian organisations have a goal to help people in need by providing help in all kinds of ways. Supplies and humanitarian workers have to be transported to every place where support is required. Even remote locations, where transport over conventional roads might be impossible, have to be accessible. Aviation is the solution for these areas. UNHAS (United Nations Humanitarian Air Service) provides passenger and cargo transport for the humanitarian community. A logistic problem arises when passengers have to be transported to multiple destinations with multiple aircraft. The goal of the research is to improve the routing and scheduling operations of humanitarian air services by means of a scheduling model. By implementing the Humanitarian Flight Optimization Model, the efficiency and effectiveness of the daily routing can be increased while giving an insight in what the impact of different routings can be on the total flight schedule.