General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

What condition leads to the deployment of the RAT?

1. Excessive electrical power draw

2. Both AC transfer busses are unpowered

3. Engine desynchronization

4. High cabin altitude

The correct answer is: Both AC transfer busses are unpowered

The deployment of the Ram Air Turbine (RAT) is primarily triggered by a situation where both AC transfer busses are unpowered. The RAT is a crucial component in aircraft systems designed to provide emergency power to essential flight control systems, hydraulics, and electrical systems in the event of a dual engine failure or significant power loss. When both AC transfer busses lose power, the aircraft's electrical system cannot maintain normal operations, and deploying the RAT enables the generation of power to sustain critical systems and instruments necessary for safe operation during an emergency. The other conditions listed, such as excessive electrical power draw or engine desynchronization, do not directly lead to the deployment of the RAT. High cabin altitude is also unrelated to the electrical systems and would not prompt the RAT to deploy, as it is more focused on cabin pressure and not on power generation needs.