What does the acronym "NDA" stand for in aircraft operation?

In the context of aircraft operation, "NDA" stands for Notice of Discrepancy. This term refers to a formal report used to document any discrepancies or issues identified during inspections, maintenance, or operation of the aircraft. The purpose of a Notice of Discrepancy is to ensure that any malfunctions or irregularities are officially recognized and addressed, contributing to the overall safety and reliability of the aircraft. Proper documentation through an NDA allows maintenance crews and engineers to track issues and implement the necessary corrective actions, ensuring that aircraft can operate safely and effectively.

The other options relate to different contexts, such as funding and regulations (National Defense Authorization), confidentiality agreements (Non-Disclosure Agreement), and design approvals (New Design Approval). While these terms are relevant in their respective areas, they do not directly pertain to the operational and maintenance processes of aircraft, making "Notice of Discrepancy" the most relevant definition for this situation.