Aeroplane Fly in Which Layer of Atmosphere?
Aircraft · 3 min read
Knowing where an aircraft flies is important for aviation professionals to understand, as it can help inform decisions such as fuel consumption, altitude, and speed.
Aviation turbine fuel (ATF) has gotten people’s attention recently because all petrol and diesel prices have gone to record highs with international oil prices soaring due to the current crisis in Ukraine. Earlier this year, news from New Delhi provided by the Business Standard pointed to a hike of 4,481.63 Indian Rupees per kiloliter or 5.2 percent to 90,519.79 Indian Rupees per kiloliter, according to a price notification of state-owned fuel retailers.
Of course, this has been a difficult hurdle for the aviation industry since jet fuels are at the top of the expenses of aircraft carriers. Moreover, jet fuel is not like any other fuel, and cannot be easily found either, especially with global supply chains under pressure.
If you want to learn more about aviation turbine fuels, keep reading as we provide you with the details.
Although gasoline was the first type of jet fuel used when the first aviation turbine engine was developed in 1939, kerosene quickly replaced it as the primary jet fuel because it had a better supply during and after World War II.
Of course, just switching from gasoline to kerosene would not be enough to guarantee performance and safety, so new standards were needed.
Governments and their corresponding authorities introduced different specifications for the fuel types that could be used, and these have been evolving ever since.
Common properties that were usually prioritized included volatility, freezing point, specific gravity, sulfur, and aromatic limits.
As can be expected, the more demanding these specifications are, the more complex it is to produce jet fuel. If we add the fact that international crude oil prices are very high, it is easy to understand why aviation turbine fuel prices are also getting higher.
To better understand the effect of international oil prices on jet fuel prices, it is a good idea to learn more about this type of fuel and the aviation business. So, we are now going to provide answers to some common questions.
Aviation Turbine Fuel (ATF) is the name given to a byproduct of crude oil used to power a jet engine. Although many people call it aviation gasoline, the reality is that the most common types currently used in aviation are kerosene-type fuels and not gasoline.
According to British Petroleum (BP), “almost all jet fuels are derived from crude oil in refineries and are manufactured to tightly controlled specifications.”
They explain that a complex combination of processes is required to produce aviation turbine fuel (ATF). These processes are:
There are different grades of fuels depending on their use: civil or military. We will focus on the most relevant ones for civil aviation.
The main grades are two, the Jet A and the Jet A-1 fuels. However, there are other grades specific to certain regions. For example, the TS-1 is mainly available in Russia and CIS states, and the Chinese grades are traditionally designated by the RP prefix, but recently renamed as No. 1 Jet Fuel and No. 2 Jet Fuel.
Another grade is the Jet B, described as a distillate covering the naphtha and kerosene fractions and a good alternative to the Jet A-1 fuel. Yet, it is not frequently used due to having higher flammability, and the only advantage is a better cold-weather performance. Therefore, it is reserved for regions like Canada, where most cities are situated in a colder climate zone.
Now, the fact is that most airplanes can operate with any of the grades mentioned above. The differences are not very big, and those differences are only determined by the specification that applies to each grade. Let’s see some of them in detail to illustrate this better.
Jet A-1 is a kerosene grade fuel suitable for most turbine-engined aircraft and it is widely available around the world. It has a flash point minimum of 38°C (100°F) and a freeze point maximum of -47°C. The main specifications for Jet A-1 grade are the UK specification DEF STAN 91-91 (Jet A-1) NATO code F-35, (formerly DERD 2494), and the ASTM specification D1655 (Jet A-1).
Mainly, or perhaps only, available in the United States, Jet A is a kerosene grade fuel with the same flash point as Jet A-1 but a higher freeze point maximum (-40°C). The specification for this fuel is the ASTM D1655 (Jet-A).
As it was mentioned above, Jet B is a distillate covering the naphtha and kerosene fractions. The ASTM provides a specification for Jet B, but in Canada, it is supplied according to the Canadian Specification CAN/CGSB 3.23.
As you can see, the freezing point is the main difference between Jet A and Jet A-1 grades. Jet A-1 freezes at less than or equal to -47°C whereas Jet-A freezes at less than or equal to -40°C. The performance difference is important for certain routes. For example, when flying from Washington to Tokyo over the polar route, the airline would want to know the freezing point of the fuel to be used.
Now that we know that these fuels derive from oil, that it takes a complex series of processes to produce it, and that there are different grades with their corresponding specifications, it is clear that an increase in oil prices will result in an increase in ATF prices.
Moreover, ATF prices have a direct impact on the economy of a country, like the case of India mentioned at the beginning. It is no surprise that they need to revise jet fuel prices twice a month and pass a price notification whenever necessary.
Also, many countries import these fuels and big increases can have a significant impact on the national capital.
For the aircraft carriers, there is also added tax, such as the local sales tax and the value-added tax imposed on this product, making the ATF price even higher in certain countries.
Although new governments have taken actions like cutting those taxes, the basis rates have remained unchanged. Let’s hope for this global crisis to come to an end soon.