When must the old logbook remain with the aircraft?

The correct answer is that the old logbook must remain with the aircraft until a newly initiated logbook is complete. This requirement ensures that all historical maintenance records and operational data are available for reference. The logbook serves as a critical document that tracks the aircraft's maintenance history, modifications, and inspections, which are essential for ensuring compliance with safety regulations and for the proper functioning of the aircraft.

Having the old logbook with the aircraft allows maintenance personnel to assess prior work and any issues that may have arisen, providing a comprehensive overview of the aircraft's care. Once a new logbook is initiated, the transition of records must be seamless, requiring the old logbook to be retained until it is clear that the new logbook is fully established and adequate documentation is in place. This process is vital in maintaining the integrity and safety of aircraft operations.

Other options might suggest different scopes of time for keeping the logbook with the aircraft. For example, keeping it until the next maintenance check or until there are no discrepancies may not capture the full requirement of complete documentation during operational phases. Keeping it for the entire flight does not address the ongoing need for historical data reference beyond immediate flight operations.