Several airplanes crashes throughout the past decades are linked to the failure of the airplane flow velocity sensor known as pitot device or pitot tube. The study of its behavior in blockage, either due to human errors or due to environmental factors, could be valuable in the development of safer, more sustainable, and robust velocity sensors with improved performance. This work aims to look into this widely used but not very widely studied sensor and presents a three-dimensional model of a pitot device along with its analysis when either one of its ports is blocked. Results show that in blockage condition pitot tubes can overestimate the velocity up to similar to %5.6.