Journal of Data Processing Olivera Petrovska, Vesna Antoska Knights and Stojche Deskovski 11 4 2021 https://doi.org/10.6025/jdp/2021/11/4/104-112 https://www.dline.info/jdp/fulltext/v11n4/jdpv11n4_2.pdf In this work, we have used a mathematical system of the aircraft and a system for automatic guidance using a GPS. Besides, we used simulations for land guidance system when using GPS. We have used Simulink for the simulating the program tools. We have compared the GBAS and ILS for simulations.