Which type of aircraft systems should a pilot be familiar with for IFS Stage II?

Being familiar with avionics, navigation, and communication systems is crucial for a pilot in IFS Stage II. These systems are essential for safe and effective flight operations. Avionics involve electronic systems used for communication, navigation, and monitoring of the aircraft's performance. A solid understanding of these systems allows pilots to proficiently manage in-flight navigation and maintain clear communication with air traffic control and other aircraft, which is vital for situational awareness and safety.

Knowledge of navigation systems is particularly important as it enables pilots to determine their position accurately and navigate to their destination safely. Communication systems play a key role in maintaining a continuous exchange of information crucial for conducting flights under varying conditions. Understanding how to operate and troubleshoot these systems can significantly enhance a pilot's ability to respond to emergencies or unexpected situations.

The other choices either represent a limited scope of knowledge required for effective piloting or do not encompass the wide array of systems that modern pilots should be able to operate.