Which of the following best describes 'major repair' in aviation?

• A. A significant alteration to an aircraft's appearance
• B. A repair involving the replacement of a critical component
• C. A routine maintenance check
• D. A minor repair performed on exterior surfaces

Answer: (B)

The term 'major repair' in aviation is best defined by the replacement of a critical component. Major repairs are significant modifications that affect the airworthiness of the aircraft and require stringent standards and approval processes under aviation regulations. This encompasses repairs that could impact the aircraft's structure, fuel systems, or systems affecting safety and operation. Such repairs typically necessitate detailed documentation and may also require re-evaluation of compliance with safety and maintenance standards.

In contrast, alterations to an aircraft's appearance do not inherently affect its operational capabilities or safety and therefore do not categorize as major repairs. Routine maintenance checks are generally less intensive inspections and do not involve significant repairs that would alter the aircraft's structural integrity. Minor repairs, particularly those limited to exterior surfaces, also do not meet the threshold for what constitutes a major repair since they typically do not affect critical functionalities or require extensive regulatory oversight.