The purpose of the Fuel Vent System is to keep the fuel tanks __________ under all operating conditions.

• A. Unpressurized
• B. Pressurized
• C. Ventilated
• D. Sealed

Answer: (A)

Keeping the fuel tanks at ambient pressure is the key idea. The fuel vent system allows air to enter and vapors to escape so the tanks don’t build up pressure as the fuel expands or is consumed. This keeps the tanks effectively unpressurized under all operating conditions.

If the tanks were sealed, pressure could build up and cause safety issues; if they were meant to be pressurized, that would add unnecessary stress to the structure; simply saying they’re ventilated doesn’t emphasize the purpose of maintaining near-atmospheric pressure.