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

Which system is prioritized for operation when the RAT is deployed?

1. Electric systems first

2. Hydraulic systems first

3. No system priority

4. APU systems first

The correct answer is: Hydraulic systems first

When the Ram Air Turbine (RAT) is deployed, the hydraulic systems are prioritized for operation. The RAT is a backup system designed to provide hydraulic power and electrical power in the event of an emergency, such as a dual engine failure or loss of electrical power. The hydraulic systems are critical for maintaining control of the aircraft, particularly for actuating flight control surfaces and landing gear. Ensuring hydraulic power during an emergency allows pilots to maintain essential aircraft control, whereas electrical systems serve other functions that, while important, are secondary to the immediate need for control and safety. Electric systems may become operational as power is restored, but the primary focus immediately after the deployment of the RAT is to restore hydraulic power to ensure the aircraft can be managed effectively during a critical scenario. The APU systems, while important for providing additional electrical power, are not the priority immediately following RAT deployment in this context. Overall, prioritizing the hydraulic systems ensures that the aircraft remains controllable, which is of utmost importance in emergency situations.