What does the clean aircraft concept entail?

The clean aircraft concept specifically refers to the condition of an aircraft's critical surfaces before takeoff. For safe flight operations, it is imperative that these surfaces, including wings, tail, and control surfaces, are free of frost, ice, or snow. The presence of such contaminants can adversely affect the aircraft's aerodynamics, leading to potential issues with lift, control, and overall performance during takeoff and flight. Ensuring that these surfaces are "clean" enhances safety and helps maintain the intended performance characteristics of the aircraft. This concept is crucial for pilots and maintenance crews to understand and implement as part of their pre-flight checks.