Which type of fuel is commonly used in commercial jet engines?

Jet A and Jet A-1 are kerosene-type jet fuels primarily used in commercial aviation due to their specific properties that make them suitable for high-performance jet engines. These fuels have a high energy density, a low freezing point, and a stable chemical composition that ensures consistent performance under various temperature conditions.

Jet A and Jet A-1 fuels also comply with stringent safety and performance standards necessary for commercial aviation, including low volatility and excellent thermal stability. Their widespread availability at airports worldwide further contributes to their preference by commercial airlines.

In contrast, Avgas 100LL is primarily used in piston engines rather than jet engines, while diesel fuel is not suitable for commercial jet engines due to its different combustion characteristics. Although biofuels are being researched and slowly introduced into aviation, they are not yet as commonly used as traditional Jet A or Jet A-1 fuels in the commercial sector.