Which factor is critical in evaluating the airworthiness of an aircraft?

The evaluation of an aircraft's airworthiness is fundamentally linked to the presence of airworthiness directives (ADs). These directives are legally enforceable regulations issued by aviation authorities to address safety issues identified in specific aircraft or engine models. They outline mandatory inspections, modifications, or repairs that must be performed to ensure continued airworthiness.

Airworthiness directives are critical because they are based on data and findings that determine whether a specific safety concern poses a risk to the operation of the aircraft. A lack of compliance with ADs can result in the aircraft being deemed unairworthy, regardless of factors such as the aircraft's age, its appearance, or the manufacturer's reputation.

The age of an aircraft might provide some context regarding wear and tear, but it does not inherently determine airworthiness. Visual aspects like color and design have no bearing on an aircraft's mechanical safety or regulatory standing. While a manufacturer's reputation can give insights into the overall quality of an aircraft, it does not replace the necessity of ensuring that all relevant airworthiness directives are followed to maintain safety compliance.