Altitude affects jet fuel in several key ways, primarily related to temperature, pressure, and the aircraft’s engine performance:

1. Temperature:
• Cooling: At higher altitudes, temperatures drop significantly. Jet fuel can gel or wax at very low temperatures, potentially clogging fuel lines and filters. To prevent this, jet fuel is designed to have a low freezing point. Jet A-1 fuel, for example, has a freezing point of -47°C (-53°F).

2. Pressure:
• Boiling Point: Lower pressure at higher altitudes can cause jet fuel to vaporize more readily. Aircraft fuel systems are designed to handle these changes, ensuring that fuel remains in the liquid state needed for combustion.


3. Engine Performance:
• Efficiency: Engines operate more efficiently at higher altitudes due to cooler temperatures and reduced air density. This can lead to better fuel economy and longer range for aircraft.
• Combustion: The combustion process in jet engines is optimized for high-altitude conditions. Lower air pressure at high altitudes requires the fuel-to-air mixture to be carefully managed to maintain efficient combustion.

Overall, jet fuel and aircraft systems are engineered to perform optimally under the varying conditions encountered at different altitudes, ensuring safety and efficiency throughout the flight.