Which document must be retained on the ground during a flight?

The retention of a copy of the mass and balance sheet signed by the Pilot-In-Command on the ground during a flight is essential for several reasons related to safety and regulatory compliance. The mass and balance sheet is a crucial document that provides the weight and balance calculations for the aircraft, which are critical for ensuring that the aircraft is loaded within safe operational limits. The Pilot-In-Command must be able to confirm that the aircraft is balanced and that its weight does not exceed the maximum limits set by the manufacturer and regulatory authorities.

This document is not only vital for the safety of the flight but also serves as a record that can be reviewed in case of an incident or investigation. Regulations require this document to be available for inspection, and keeping it on the ground allows for accountability and operational planning.

In contrast, while the personal licenses of the flight crew, the aircraft's maintenance logbook, and a troubleshooting guide are all important aspects of aviation operations, they are not required to be physically retained on the ground during a flight for regulatory compliance purposes in the same manner as the mass and balance sheet. The licenses may need to be presented before takeoff but do not need to be kept on board for the entirety of the flight, and the maintenance logbook must