Which factor is NOT part of the pilot self-assessment process?

The correct answer is the factor related to aircraft maintenance check, as it does not pertain to the pilot's personal self-assessment process. The pilot self-assessment process is focused on the individual's condition, mindset, and ability to safely operate the aircraft. It includes evaluating personal health status, emotional well-being, and physical fatigue—factors that can significantly impact flight performance and decision-making.

Illness speaks to the pilot's physical health, which is crucial for ensuring cognitive function and reaction times during flight. Stress and emotional state can greatly influence judgment and concentration, which are vital for safe flight operations. Fatigue is equally important, as it can impair cognitive functions, leading to errors in judgement and reduced physical capabilities.

In contrast, an aircraft maintenance check is a responsibility that falls to the maintenance crew and does not directly assess the pilot’s fitness to fly. While it is highly important for the aircraft's airworthiness, it is separate from the evaluation of a pilot's readiness and state for flying. Therefore, this choice does not belong in the pilot self-assessment framework.