When does RAT autodeployment occur?

RAT autodeployment occurs under specific conditions designed to ensure the continued operability of critical systems in the aircraft. In the case of the Dassault Falcon 7X, the deployment of the Ram Air Turbine (RAT) is triggered when there is a complete loss of hydraulic power, which typically happens when all three engines fail and/or all three generators fail. This is a safety feature that allows for emergency hydraulic pressure to be generated, enabling essential systems to function even in a catastrophic failure scenario.

The RAT serves dual purposes: it helps maintain control of the aircraft by providing hydraulic power for critical flight controls and it powers essential electrical systems. Such a deployment is not intended to activate during less severe failures, such as the failure of only one engine or one generator, as these conditions usually do not necessitate the same level of emergency response. This is why other scenarios listed do not trigger RAT deployment, focusing instead on the most critical situation of total engine and generator loss.