When does the auto-throttle automatically engage?

The auto-throttle feature on the Dassault Falcon 7X is designed to enhance flight safety and efficiency by managing engine power automatically in certain conditions. When the autopilot is engaged and the aircraft is in either high speed or low speed protection mode, the auto-throttle activates to maintain safe operating parameters and prevent stall or overspeed situations. This functionality ensures that the aircraft can operate within the optimal performance envelope, providing protection against exceeding the aircraft's limits in both high and low-speed scenarios.

Engagement of the auto-throttle under these specific conditions is vital for maintaining stability and control without requiring constant manual input from the pilot, thereby allowing them to focus on other critical flight tasks. This also aids in compliance with safety regulations and improves overall flight efficiency.

In contrast, the other choices do not accurately describe when the auto-throttle engages. It does not activate exclusively during takeoff, nor does it operate specifically during low-speed stall conditions or under all flight conditions indiscriminately. This capability is tailored to specific instances when the autopilot is active to maximize safety and performance.