Which inert gas is typically used to inert a fuel tank?

Which inert gas is typically used to inert a fuel tank?

• A. Oxygen
• B. Dry Nitrogen
• C. Argon
• D. Helium

Answer: (B)

Inerting a fuel tank means replacing the air inside with a non-reactive gas to reduce the chance of ignition by lowering the oxygen level. The gas typically used is dry nitrogen because it is inert, readily available from air separation, and inexpensive. Its dryness matters too, since moisture in the tank can lead to corrosion or fuel contamination and moisture can complicate ignition risks. Oxygen would defeat inerting by providing the oxidizer that fuels combustion. While argon and helium are also inert, they’re not practical for aircraft fuel tanks due to cost and availability, so dry nitrogen is the standard choice.

Inerting a fuel tank means replacing the air inside with a non-reactive gas to reduce the chance of ignition by lowering the oxygen level. The gas typically used is dry nitrogen because it is inert, readily available from air separation, and inexpensive. Its dryness matters too, since moisture in the tank can lead to corrosion or fuel contamination and moisture can complicate ignition risks. Oxygen would defeat inerting by providing the oxidizer that fuels combustion. While argon and helium are also inert, they’re not practical for aircraft fuel tanks due to cost and availability, so dry nitrogen is the standard choice.