Jet fuel is flammable, requiring careful management in aviation. This specialized fuel, primarily kerosene-based (Jet A or Jet A-1), is designed for gas-turbine engines. Its flammability differs significantly from more volatile fuels like gasoline. These differences impact its safe handling and use.
Understanding Jet Fuel’s Flammability
Jet fuel’s flammability is defined by its flash point and autoignition temperature. The flash point is the lowest temperature at which a liquid produces enough vapor to form an ignitable mixture with air when exposed to an ignition source. For Jet A and Jet A-1, this temperature is typically above 38°C (100°F). Standardized tests determine this parameter.
The autoignition temperature refers to the lowest temperature at which a fuel spontaneously ignites without an external ignition source. For jet fuel, this temperature is approximately 210°C (410°F). This property is assessed using specific methods. For jet fuel to ignite, there must be a suitable concentration of fuel vapor mixed with air, an ignition source, and the temperature must be at or above its flash point.
At typical ambient temperatures, jet fuel is less volatile than gasoline. Gasoline readily vaporizes at room temperature, making it more prone to ignition from a casual spark. Jet fuel’s higher flash point means it requires more heat to produce enough flammable vapors to ignite, contributing to its relative safety during routine handling.
Addressing Common Misconceptions
A common misconception is that jet fuel is not very flammable, or even “doesn’t burn.” This idea arises because jet fuel is less volatile than gasoline at room temperature. For instance, if a lit match is dropped into a puddle of jet fuel, it might simply extinguish, whereas it would ignite gasoline immediately. This visible difference can be misleading.
Jet fuel is not non-flammable; it requires specific conditions to ignite. When heated, such as during an aircraft fire, it readily produces flammable vapors and can burn intensely. Within a jet engine, the fuel is atomized into a fine mist and compressed, creating ideal conditions for combustion.
The conditions necessary for ignition are regularly met in operational environments or during accident scenarios. While its higher flash point makes it safer to handle than gasoline, it burns intensely once ignited under the right circumstances.
Ensuring Safe Handling
Due to its flammability, extensive safety measures are in place for its handling, storage, and transportation. Proper ventilation prevents flammable vapor accumulation. This ensures the air-to-fuel vapor mixture remains outside the ignitable range.
During fueling, grounding and bonding prevent static electricity discharge. As jet fuel flows through pipes and hoses, friction can generate static electrical charges, which could create a spark. Bonding connects conductive materials to equalize electrical charges, while grounding provides a safe path for static charges to dissipate.
Specialized storage tanks with fire suppression systems are standard at airports and refineries. These systems, along with static dissipator additives, reduce ignition risk. These safety measures ensure jet fuel can be handled and transported safely.