What does the aircraft designation E represent?

The designation "E" in aircraft classification is used to identify aircraft that are equipped for special electronic installations. This can encompass a variety of roles, such as electronic warfare, reconnaissance, or signals intelligence, where the aircraft is modified or designed specifically to handle electronic operations. These aircraft are integral to military operations, as they contribute to gathering intelligence and conducting electronic surveillance, thereby enhancing situational awareness and operational effectiveness.

The other designations serve different purposes: fighter aircraft are built for air-to-air combat, helicopters are typically used for a range of missions including search and rescue, and missile carriers are specifically designed to transport and launch missiles. Hence, "E" clearly points to specialized electronic capabilities.