Definition
The internal rules and decision-making behavior built into an aircraft's automated systems — particularly the autopilot, flight director, and flight management system — that determine how those systems respond to pilot inputs and changing flight conditions. Control logic governs which mode is active, how modes transition from one to another, what the system will do automatically, and what it will refuse to do.
Plain English
The set of built-in rules that decide how the aircraft's automation behaves. It is the 'thinking' inside the autopilot and related systems that decides what happens when you push a button, change a setting, or when the airplane reaches a target altitude or course.
Context Anchor
Seen in discussions of aircraft automation, especially when a pilot must understand why an autopilot, flight director, or flight management system is behaving a certain way.
Derivation
Control' comes from the Old French contrerolle, meaning to check or verify against a record. 'Logic' comes from the Greek logikē, the art of reasoning. Together the phrase points to the built-in reasoning the system uses to decide how to control the aircraft.
Why Pilots Care
Knowing the control logic helps pilots anticipate system responses and avoid mode confusion during automated instrument approaches.
Intuition Check
Do not read “control logic” as the pilot’s judgment or common sense. Here it means the aircraft system’s built-in rules for what it will do under specific conditions.
Example Sentence 1
Before flying a new aircraft, the pilot studied the autopilot's control logic so she would know exactly how it would behave when capturing an altitude or intercepting a course.
Example Sentence 2
Unexpected level-off occurred because the control logic prioritized altitude capture over vertical speed.