What does "electromagnetic interference" (EMI) affect in aircraft?

Electromagnetic interference (EMI) is a phenomenon that occurs when electromagnetic fields disrupt the normal operation of electronic devices. In the context of aircraft, this interference can significantly affect the performance of electronic equipment, such as avionics, communication systems, and navigation instruments. These electronic systems are critical for safe flight operations, as they rely on precise signals for functionality. EMI can cause issues such as signal degradation, erroneous readings, or complete malfunction of equipment, which can jeopardize safety and efficacy during flight.

The other options refer to aspects of the aircraft that are typically not impacted directly by EMI. Structural integrity relates to the physical durability of the airframe, while hydraulic systems and fuel efficiency are primarily influenced by mechanical and fluid dynamics factors rather than electromagnetic interference. Thus, the focus of EMI is firmly on the performance of electronic systems within the aircraft.