What are the flashpoints for AVGAS and Jet Fuel?

What are the flashpoints for AVGAS and Jet Fuel?

• A. AvGas - low, flammable; Jet A - high, combustible
• B. AvGas - high, nonflammable; Jet A - low, flammable
• C. AvGas - low, nonflammable; Jet A - high, nonflammable
• D. AvGas - high, flammable; Jet A - low, combustible

Answer: (A)

Flashpoint is the temperature at which a liquid’s vapors ignite in air with an ignition source. A lower flashpoint means the liquid is more readily ignitable, i.e., more volatile. AVGAS has a lower flashpoint than Jet fuel, so it is described as low and flammable. Jet fuel has a higher flashpoint relative to AVGAS, so it is described as high and combustible in this context. The idea is that AVGAS vaporizes and can ignite at a lower temperature, while Jet fuel requires a somewhat higher temperature to reach a flammable vapor concentration, hence the “combustible” label in the given option. Note that both fuels are flammable in practical terms, but the classification here reflects their relative tendency to ignite based on their flashpoints.

Flashpoint is the temperature at which a liquid’s vapors ignite in air with an ignition source. A lower flashpoint means the liquid is more readily ignitable, i.e., more volatile.

AVGAS has a lower flashpoint than Jet fuel, so it is described as low and flammable. Jet fuel has a higher flashpoint relative to AVGAS, so it is described as high and combustible in this context. The idea is that AVGAS vaporizes and can ignite at a lower temperature, while Jet fuel requires a somewhat higher temperature to reach a flammable vapor concentration, hence the “combustible” label in the given option.

Note that both fuels are flammable in practical terms, but the classification here reflects their relative tendency to ignite based on their flashpoints.