What does "POPEYE" refer to in aviation terminology?

"POPEYE" in aviation terminology refers to visibility conditions during flight. Specifically, it is associated with the scenarios where visibility may be reduced due to weather conditions, such as fog or mist, which can significantly impact flight operations and flight safety. Understanding visibility conditions is crucial for pilots as it aids in making informed decisions about takeoffs, landings, and overall flight paths.

The other options pertain to distinct concepts in aviation. Flying at maximum altitude involves operational limits of an aircraft, not specifically visibility. A maneuver to evade radar would relate to stealth tactics and evasion techniques rather than visibility. An emergency landing protocol deals with procedures to follow during unforeseen situations requiring a landing but does not address visibility itself.