This report is the summary of work done in the CIMAR project of collaboration between IST (Lisboa) and the Icare Project (INRIA Sophia Antipolis) for vision-based control applied to an autonomous aircraft. An unified modeling framework is defined and the vision-based auto-landing of the UAV model is analyzed, based on the classical alternative between position-based and image-based visual control. The controller design is adapted for both approaches and simulations results are presented in order to validate the proposed solutions and allow for a critical evaluation of the two approaches.