Key Takeaways
- Turbine fuel is kerosene-type fuel for gas-turbine engines. It is defined by specifications (ASTM D1655, DEF STAN 91-91, GOST 10227 and CGSB-3.22), not by a fixed recipe. A batch qualifies by meeting limits.
- The key limits include a maximum freezing point of -40°C for Jet A and -47°C for Jet A-1, a minimum flash point of 38°C, density of 775 to 840 kg/m³ and no more than 25% aromatics, as Chevron listed them in 2004.
- Only approved additives, at parts-per-million levels, may go in. Jet A-1 contains a static dissipator, while US Jet A usually contains none or only an antioxidant.
- Sustainable aviation fuel is blended, up to 50% for most pathways, because on its own it lacks the aromatics that keep seals sealed.
Most explanations of jet fuel list what’s in it. This one looks at what the fuel must do, and the limits that make it safe for a turbine engine at altitude. For the hydrocarbon breakdown, with a chart of Jet A samples, see our guide to what aviation fuel is.
What Is Turbine Fuel?
Turbine fuel, also called aviation turbine fuel, is the kerosene-type fuel burned by turbofans, turboprops and turboshaft helicopters. It isn’t one product. Four civil grades are widely specified, and each has limits it must meet. Chevron’s Aviation Fuels Technical Review summarises them:
| Property | Jet A | Jet A-1 | TS-1 | Jet B |
|---|---|---|---|---|
| Specification | ASTM D1655 | DEF STAN 91-91 | GOST 10227 | CGSB-3.22 |
| Freezing point, max (°C) | -40 | -47 | -50 (chilling point) | -51 |
| Flash point, min (°C) | 38 | 38 | 28 | None listed |
| Density (kg/m³) | 775 to 840 | 775 to 840 | 774 min at 20°C | 750 to 801 |
| Aromatics, max | 25% vol | 25% vol | 22% mass | 25% vol |
| Smoke point, min (mm) | 18 | 19 | 25 | 20 |
| Net heat of combustion, min (MJ/kg) | 42.8 | 42.8 | 42.9 | 42.8 |
That table reflects the specifications as Chevron wrote them in fall 2004, and specifications are revised over time. Chevron’s table lists each grade against one specification, but ASTM D1655 covers Jet A and Jet A-1 alike, so check the current edition before you rely on a figure.
Why Does Turbine Fuel Have So Many Limits?
Each limit guards against a specific failure, and they interact. Chevron notes that as total aromatics rise, density, final boiling point and freezing point rise too, while smoke point falls. That is why the specification caps several properties at once rather than naming ingredients.
- Freezing point keeps the fuel liquid in the cold. ATSDR notes that Jet A-1’s lower limit suits long international flights, especially polar routes in winter.
- Flash point limits how readily the fuel’s vapour ignites during handling. Chevron lists a 38°C minimum for Jet A and Jet A-1, and ATSDR notes that the carrier fuel JP-5 has a higher, 60°C flash point for safer handling aboard ships.
- Aromatics, naphthalenes and smoke point are capped because these compounds form carbon particles in the combustor, which can disrupt airflow and cause visible smoke.
- Thermal stability matters because the fuel acts as a heat sink for oil, hydraulic fluid and air conditioning, and poor stability leaves deposits.
- Lubricity comes from trace oxygen, nitrogen and sulfur compounds, and refining that removes them can leave a fuel that needs a lubricity additive at around 10 ppm.
What Additives Can Go Into Turbine Fuel?
Only additives approved in the specification, in the stated amounts, which are measured in parts per million. Chevron says an additive must be tested at four times its maximum dose alongside other additives before approval. Its summary of civil grades:
| Additive | Purpose | Jet A | Jet A-1 |
|---|---|---|---|
| Antioxidant | Prevents gums and peroxides forming in storage | Allowed | Required in hydroprocessed fuel, otherwise optional |
| Static dissipator | Speeds the dissipation of static charge | Allowed | Required |
| Metal deactivator | Blocks metal contamination that degrades stability | Allowed | Allowed |
| Corrosion inhibitor and lubricity improver | Protects metal and adds lubricity | By agreement | Allowed |
| Icing inhibitor (FSII) | Stops ice crystals forming from dissolved water | By agreement | By agreement |
| Thermal stability additive | Raises heat tolerance in military fuel | Not allowed | Not allowed |
In practice, international Jet A-1 contains a static dissipator and may carry an antioxidant, while US Jet A usually contains no additives or only an antioxidant. Chevron adds that most commercial aircraft have filter heaters and that icing inhibitor isn’t used by large commercial carriers. Additive use is the main difference between commercial and military fuels.
How Does SAF Change the Picture?
Sustainable aviation fuel has to end up meeting the same specification. According to the IATA SAF Handbook, neat SAF already meets most requirements except its aromatic content and, in some cases, viscosity and density. So it’s blended with conventional fuel, up to 50% depending on the pathway, and then re-certified to ASTM D1655. Once blended, it is treated as ordinary Jet A or Jet A-1, as IATA’s technical certification fact sheet explains.
Aromatics are the reason. GreenAir News reported in 2022 that aromatics swell seal materials, and without them seals can shrink and leak in some older engines and fuelling equipment. Mixing a zero-aromatic component 50/50 with a conventional fuel at about 17% aromatics leaves at least 8%. Our SAF guide covers the pathways.
What Should Buyers Check?
Ask which grade and specification each batch meets and for the certificate to prove it, and confirm the grade your aircraft and airport need. Don’t assume additives: a Jet A uplift may carry none. Our UAE fuel supply guide covers certificates, audits and contract terms.
Frequently Asked Questions
What is turbine fuel?
Turbine fuel is kerosene-type fuel for gas-turbine engines such as turbofans, turboprops and turboshaft helicopters. It is defined by specifications, mainly ASTM D1655 and DEF STAN 91-91, rather than by a fixed recipe.
Is Jet A the same as turbine fuel?
Jet A is one kind of turbine fuel. Jet A-1, TS-1 and Jet B are others. Jet A has a maximum freezing point of -40°C and Jet A-1 -47°C, according to Chevron’s 2004 summary.
What additives are in jet fuel?
Only approved ones, in parts-per-million amounts. International Jet A-1 contains a static dissipator and may carry an antioxidant, while US Jet A usually contains none or only an antioxidant.
Why is SAF blended with conventional jet fuel?
Neat SAF lacks the aromatics that keep some seals swollen, so it’s blended, up to 50% depending on the pathway, and re-certified to ASTM D1655.
Read the Full Composition Guide
For the hydrocarbon classes in Jet A, the types of aviation fuel and which aircraft use which, see our main guide.