Paper Title
Mathematical Model Development and Transition Flight Simulation of a Hybrid Vtol Fixed-Wing Drone

Abstract
A medical transport drone is currently developed in the Aerospace Engineering Department, Institut Teknologi Bandung (ITB). The drone will be used for transporting medical supplies to remote areas in Indonesia. Based on its operating requirements, a hybrid vertical take-off landing (VTOL) fixed-wing drone type is used as the basic design. In the initial development process, a commercial of the shelf (COTS) drone product is used as the platform. This paper specifically discuss the development of mathematical model of the drone, including aerodynamic, mass and moment of inertia, and propulsion system model. The aerodynamic model of the drone is developed by using a low order analytical method, utilizing a software named Athena Vortex Lattice (AVL). The mass and moment of inertia model is obtained from analytical estimation assisted by computer-aided design (CAD) solid modeling. Data from various sources are collected to obtain the propulsion system model.The obtained mathematical modelis then be used in a simulation of transition flight process of the drone. Climb and fall maneuver is used in the simulation. The simulation results show that transition flight phase is critical since it can cause stall and make the drone lose altitude in a short amount of time. Flight control system needs to be developed at each flight stage. Keywords - Mathematical Model, Hybrid VTOL Fixed-wing Drone, AVL, CAD, Transition Flight.