Aircraft Fuel Systems Flashcards

What color is 100LL aviation gasoline?

Answer: Blue

100LL avgas is dyed blue to distinguish it from other aviation fuel grades and prevent misfueling.

What type of pump is typically used as the electric boost pump in an aircraft fuel system?

Answer: Centrifugal pump

Electric boost pumps are typically centrifugal type, providing low-pressure fuel flow to assist the engine-driven pump during start and as a backup.

What is an integral fuel tank?

Answer: A portion of the aircraft structure that has been sealed to contain fuel

Integral fuel tanks are created by sealing a section of the aircraft's existing structure, such as a wing bay, so that the structure itself serves as the fuel container.

What is the primary purpose of a fuel strainer (gascolator) in an aircraft fuel system?

Answer: To remove water and sediment from the fuel

The fuel strainer (gascolator) filters out water and sediment from the fuel to prevent contaminants from reaching the carburetor or fuel injectors and causing engine problems.

Jet-A turbine engine fuel appears what color in its natural state?

Answer: Clear to straw-colored

Jet-A fuel is not dyed and appears as a clear to straw-colored liquid, unlike aviation gasoline which is color-coded by grade.

What is 'vapor lock' in an aircraft fuel system?

Answer: A condition where fuel vaporizes in the lines, blocking adequate fuel flow to the engine

Vapor lock occurs when fuel vaporizes within the fuel lines or pump, creating a vapor barrier that prevents adequate liquid fuel flow to the engine.

What is the purpose of fuel tank vents in an aircraft fuel system?

Answer: To maintain atmospheric pressure in the tank and allow proper fuel flow as fuel is consumed

Fuel tank vents maintain atmospheric pressure inside the tanks, preventing tank collapse from internal vacuum and ensuring consistent fuel flow to the engine as fuel is consumed.