This course introduces the fundamental concepts of electronic systems used in aircraft, building on prior knowledge of electrical circuits to include semiconductor physics and electronic device behavior. Students study diodes, rectifiers, transistors, and basic amplification circuits, along with their applications in aviation systems. The course also addresses power supply configurations and introduces basic signal processing concepts. Practical learning is embedded through circuit assembly, measurement of electrical and electronic signals, and troubleshooting of components, enabling students to understand system functionality and limitations in alignment with EASA Modules 3 and 4.