This thesis is a technical analysis of the ice and rain protection systems of the Boeing 737 Next Generation (NG), which combines aerodynamic principles, icing physics, system design, regulatory standards, and operational factors. The paper starts with the definition of aircraft icing mechanisms, such as the behavior of supercooled droplets, the types of ice accretion, and the aerodynamic and operational effects of ice accretion. These phenomena are placed in a detailed literature review in the historical research, contemporary thermodynamic modeling, and certification standards, including FAR/CS-25 Appendix C and O. The main part of the thesis examines the Boeing 737 NG ice protection architecture, such as pneumatic thermal anti-icing of wing leading edges and engine inlet cowls, electrically heated air-data probe systems, flight deck windows, and fluid systems. Boeing system descriptions and maintenance documentation are used to examine system components, functional principles, control logic and failure modes. The experiment measures the effectiveness of the system in reducing lift degradation, drag increment, stall-margin degradation, and sensor malfunction related to icing. New technologies of ice protection such as electrothermal systems, intelligent detection, icephobic surfaces, and hybrid architectures are discussed in relation to the gaps in research on SLD behavior, limitations of computational models, material durability, and integration of more-electric aircraft. The results point out the limitations and opportunities of existing 737NG solutions and determine the key areas of technological improvement, namely, energy efficiency, high-tech sensing, and multi-physics simulation.