JET A1

Jet A-1 is a type of aviation fuel (jet fuel) used in turbine-engine aircraft such as commercial airliners, cargo planes, business jets, helicopters with turbine engines, and turboprops. It’s one of the most common jet fuels in the world (especially outside the U.S.).

✈️ What Jet A-1 Is

1. Type: Aviation turbine fuel (ATF), specifically a kerosene-based fuel.
2. Use: Powers gas turbine engines — including turbofans, turbojets, and turboprops — in civil and military aircraft.
3. Standardization: Produced to stringent international specifications such as ASTM D1655 and DEF STAN 91-91 to ensure consistent quality and safety.

🧪 Key Characteristics

1. Freezing Point: Maximum −47 °C (−52.6 °F) — lower than Jet A (−40 °C) so it resists gelling at high altitudes.
2. Flash Point: Minimum 38 °C (100 °F) — relatively high for safety in handling and storage.
3. Density: Typically 775–840 kg/m³ at 15 °C, important for accurate fuel weight and performance calculations.
4. Energy Content: Around 42–43 MJ/kg, giving high energy per unit mass for efficient flight.
5. Composition: Mostly hydrocarbons from refined kerosene; may include small amounts of additives (e.g., static dissipaters) to improve performance.

🌍 Where It’s Used

1. Worldwide Standard: Jet A-1 is the predominant jet fuel used globally, except in the U.S., where Jet A is more common.
2. Why A-1: Its lower freezing point makes it especially suitable for long-haul flights and operations in cold climates.

🛢️ Compared to Other Aviation Fuels

1. Jet A (U.S.): Very similar but with a higher freezing point (−40 °C).
2. Jet B: Used in extremely cold climates; more volatile and flammable, so less common.
3. Avgas: A gasoline-type fuel for piston engines — not suitable for turbine engines.

In short, Jet A-1 is the internationally standardized kerosene-type jet fuel that keeps most commercial and many military aircraft flying safely and efficiently under a wide range of conditions.