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

Which components are powered by the left hydraulic systems?

1. Flight controls and left thrust reverser

2. Landing gear and flaps

3. Brakes and elevator assembly

4. APU fuel system and electrical systems

The correct answer is: Flight controls and left thrust reverser

The correct choice identifies the components powered by the left hydraulic systems, which include the flight controls and the left thrust reverser. In many aircraft, hydraulic systems are divided into two or more independent systems to ensure redundancy and reliability. The left hydraulic system typically powers critical systems associated with the aircraft's control surfaces, such as the ailerons and elevators, as well as components related to thrust reversers on the left engine. The left hydraulic system's involvement in flight controls is essential for maneuverability and stability, which are paramount for safe flight operation. Including the left thrust reverser indicates that this hydraulic system also plays a role in deceleration during landing, allowing for shorter landing distances and enhanced safety. Other choices feature components that are usually powered by different hydraulic systems or electrical systems. For example, the landing gear and flaps are typically powered by a separate hydraulic system that can be designated as the right or auxiliary system. Brakes and elevator assemblies might also utilize hydraulics but are not exclusively tied to the left system. APU fuel systems and electrical systems, on the other hand, are generally powered by different means, not directly controlled by hydraulic systems.