What kind of inspection typically occurs at the end of an aircraft's operational cycle?

The D-Check, or heavy maintenance inspection, is typically performed at the conclusion of an aircraft’s operational cycle. This comprehensive inspection involves a detailed examination of the aircraft and the associated systems, and it often requires significant repairs or modifications to ensure the continued airworthiness of the aircraft.

During a D-Check, aircraft structures are thoroughly inspected, all components are examined for wear and tear, and necessary maintenance is carried out to address any issues that could affect the safety and reliability of the aircraft in future operations. This inspection is extensive and usually takes the longest duration compared to other checks, further reinforcing the importance of maintaining the aircraft after a long operational period.

In contrast, the other options represent different levels of inspections that occur at various intervals throughout the aircraft’s lifecycle rather than at the conclusion of an operational cycle. The A-Check is a routine, light inspection conducted frequently (usually every few hundred flight hours), the B-Check is performed less often and focuses on more specific areas with minor maintenance tasks, and the C-Check is an intermediate inspection that is more extensive than the A and B Checks but still does not encompass the full scope of a D-Check.