The aim of this article is to present an optimal model for the behavior of a tilt wing aircraft during its transition state. A tilt wing aircraft is a hybrid between a helicopter and a plane, which has the capabilities of both parts, meaning that it can stand still and hover and by tilting its wing 90 degrees to act like a regular plane. Overall, a tilt rotor aircraft has the extended merits of vertical take offs and landings, to stand still and hover in mid air, while being able to travel in long distances efficiently. The novelty of this article stems from: a) the analysis of the aircraft during the transition between helicopter mode and plane for the angles between 0-90 degrees, b) the comparison between the model extracted from the simulations and tests from a wind tunnel, and c) the proposal for an optimal design for a tilt wing UAV. The efficiency of the proposed modeling approach has been evaluated in multiple simulated and experimental verification.