Aircraft Hydraulic and Pneumatic Power System

Front

What are the learning objectives related to Aircraft Hydraulic Systems?

Back

Viscosity, Chemical Stability, Flash Point, Fire Point, Types of Hydraulic Fluids, Intermixing Fluids, Compatibility with Aircraft Materials, Hydraulic Fluid Contamination, Contamination Check, Contamination Control, Hydraulic System Flushing, Health & Handling.

Front

Define viscosity in the context of hydraulic fluids.

Back

Viscosity is a measure of a fluid's resistance to flow, which affects the performance of hydraulic systems.

Front

What is Pascal's Law?

Back

Pascal's Law states that pressure applied to an enclosed fluid is transmitted equally throughout the fluid in all directions.

Front

What are the three principal categories of hydraulic fluids?

Back

1. Mineral-Based Fluids 2. Polyalphaolefin-Based Fluids 3. Phosphate Ester-Based Fluids.

Front

What is the significance of flash point in hydraulic fluids?

Back

Flash point is the temperature at which a liquid gives off vapor in sufficient quantity to ignite momentarily; a high flash point indicates good resistance to combustion.

Front

What are the characteristics of phosphate ester-based fluids like Skydrol®?

Back

They are extremely fire-resistant, used in most commercial transport category aircraft, and have unique fire-resistant and self-extinguishing properties.

Front

What is the importance of chemical stability in hydraulic fluids?

Back

Chemical stability is crucial as it determines a liquid's ability to resist oxidation and deterioration over time.

Front

What should be done if an aircraft hydraulic system is serviced with the wrong type of fluid?

Back

Immediately drain and flush the system and maintain the seals according to the manufacturer’s specifications.

Front

What are the two general types of contaminants in hydraulic systems?

Back

1. Abrasives (e.g., core sand, weld spatter) 2. Non-abrasives (e.g., oil oxidation, worn particles from seals).

Front

What is the procedure for hydraulic fluid sampling?

Back

Pressurize and operate the hydraulic system, then take samples from various locations, ensuring proper personal protective equipment is worn.