Which record block documents discrepancies found in aircraft maintenance?

The correct answer is Block 9, which is designated for documenting discrepancies found during aircraft maintenance. This block is crucial as it provides a detailed record of any issues or faults identified during maintenance checks. By accurately filling this block, maintenance personnel ensure that any discrepancies are formally acknowledged and can be addressed in subsequent maintenance procedures or inspections.

Tracking discrepancies in Block 9 contributes to maintaining the overall airworthiness of the aircraft and ensures compliance with safety regulations. It serves as a communication tool among maintenance teams, helping them to keep a clear and concise record of issues that may affect the aircraft's performance or safety.

The other blocks, such as Blocks 10, 11, and 12, have different purposes related to aircraft records, such as maintenance actions performed and logbook documentation, but Block 9 specifically focuses on recording discrepancies. Understanding the role of Block 9 is essential for ensuring effective aircraft maintenance practices.