Airplanes in different forms and sizes have dominated the skies for decades. From the bicycle wonder of the Wright brothers to the supersonic miracles of the Concorde and the brute force and maneuverability of fighter jets, airplanes never cease to amaze us. Just like in other combustion engines, it is no secret that for an aircraft engine to generate thrust and eventually achieve flight, it needs fuel to run its engines. This leaves aviation enthusiasts to wonder: do all airplanes use the same fuel?
All airplanes don’t use the same fuel. Airplanes of different kinds use different variations of fuel to run their engines based on the purpose they are designed to fulfill.
There seems to be a general misconception that all aircraft engines run on the same fuel. It is not totally out of place to hear the word jet fuel thrust into the air when questions arise on the kind of fuel used in jet engines. However, the answer to this question is more elaborate and complex than a combination of words that seem rather colloquial.
Nevertheless, as an aviation enthusiast, possessing the knowledge that different planes use a variation of jet fuel is not enough. For this reason, in this article, we would go beyond this simple answer and explore the following areas:
- Types of fuel used in jet engines.
- Factors affecting the kind of fuel used.
- Prospects for jet fuel.
Table of Contents
Types of Fuel Used in Airplane Engines
Generally, all fuel types used in various jet engines are of a higher quality than those used in other transport systems because of their critical applications. They also contain certain additives that reduce the possibility of icing and explosions due to low and high temperatures, respectively. However, the basic types of jet engines are:
- Kerosene-based jet fuel
- Jet propellant fuel
- Av-gas fuel (aviation gasoline)
- Compressed natural gas and liquified natural gas
Kerosene-Based Jet Fuel
As the name implies, kerosene-based fuel commonly consists of a kerosene base with other additives that increase its purity and efficiency. This type of fuel is rich in hydrocarbons and can be used in both compression or turbine engines. Their efficiency and high quality make them the best fuel type choice for commercial flight. Kerosene-based jet fuel is further divided into:
- Jet A (exclusive to the USA).
- Jet A1 (used in most turbine engines outside the USA).
- Jet B (a favorite in remarkably cold regions).
Jet Propellant Fuel (Military-Based Fuel)
Like its counterpart the kerosene-based jet fuel, the jet propellant (JP) fuel contains kerosene but with a mix of hydrocarbons, naphthenes, alkenes, and aromatic hydrocarbon.
This cocktail of hydrocarbons provides the jet propellant with a higher flash point than the kerosene-based fuel. This feature allows the jet propellent fuel to mitigate the heat and stress associated with high-speed supersonic flights. Sub-divisions of the jet propellent fuel ranges from JP1 to JP8.
Av-Gas Fuel (Aviation Gasoline Used In Piston Aircraft)
No, this is not the same gasoline that keeps your car running.
The av-gas fuel possesses a higher octane rating than the gasoline that keeps our cars running, and contains the right mixture condition for take-off and flight cruise in situations where reduced fuel consumption is critical.
It is a stable and very reliable fuel with anti-knock properties. Furthermore, its stability, safety, and reliability in most environments make it most suitable for small piston-powered aircraft used for a select number of purposes that require a lot of maneuvers.
Compressed Natural Gas and Liquified Natural Gas
Compressed and liquified natural gases present a radical alternative to fossil-oil, which has become the norm.
Aircrafts such as the Russian Tupolev 155 (Tu-155) and American (NASA) Sugar Freeze are optimized to allow the use of compressed and liquified natural gases in their engines.
However, the low specific energy of this fuel type makes it less desirable than its fossil-oil counterparts.
Sugar Breeze
Can Airplanes Run on Gasoline?
Finally, we have arrived at the one question that has been on your mind: can airplanes run on gasoline?
Jet engines run at very high temperatures, which means that gasoline is a poor fuel because it has a low octane rating and tends to burn too fast. Again, the answer is no. Due to its lower octane rating, it’s highly unlikely that you’ll thrust into the air with an airplane that runs on motor gasoline.
Factors Affecting the Kind of Fuel Used in an Airplane
A few factors influence the type of fuel used to run jet engines. Certain fuel types may be suitable for some airplane types but unsuitable for others, owing to varying combustion rates and other factors.
Here are the most common factors affecting the kind of fuel used in an airplane:
- Purpose and design of aircraft.
- Type of aircraft engine used.
1. Purpose and Design of Aircraft
Some airplanes were designed for their sheer speed, maneuverability, and bombardment ability as in fighter jets. Others prioritize efficiency, steadiness, and smooth flight like in commercial airplanes. The purpose and design of an airplane greatly influence the kind of fuel that will be used to run its engines.
Commercial planes
The primary purpose of commercial planes is for the safe movement of people and light freights from one place to another. Therefore, as a paramount point of consideration, aircraft engineers design engines that offer safety first above everything else.
Consequently, commercial planes use high-quality kerosene-based fuel. This blend of kerosene-based fuel must also pass a very high purity test to ensure efficient combustion in the engines of commercial planes.
Military planes
Military planes are a different breed of airplanes. Unlike commercial planes, military planes earn their legitimacy from their super-sonic speed, combat worthiness, and bombardment ability.
This factor affects the engine specifications and of course the fuel type of these military planes. The fuel used by the jet engines of military planes contains a blend of kerosene and hydrocarbons, naphthenes, alkenes, and aromatic hydrocarbons with a high flash point. As explained earlier, this fuel type copes well with the heat and stress associated with the supersonic flights of fighter jets.
Light aircraft
A light aircraft as the name suggests is a lightweight airplane with very high maneuverability and low speed. These kinds of airplanes are used for special purposes such as sight-seeing, agriculture (fertilizer spraying), photography, and so on. As a consequence, the kind of fuel needed for this plane type needs to be stable, safe, and predictable. These factors make avgas (aviation gasoline) a more suitable choice for light aircraft.
2. Type of Aircraft Engine Used
Another factor to be considered when choosing the right fuel type to be used in a plane is the type of engine the fuel is going to run in the first place. This parameter is very important as it goes a long way to define the purpose of the plane. Different engine types require a different kind of fuel to run them based on international specifications.
Turbine engines
Most airplanes use different variations of turbine engines. These engines are complex with a lot of mechanical parts that rapidly generate heat, which creates the need for a fuel that is combustion efficient and anti-heating. This makes the kerosene-based fuel and jet propellant fuel the best fuel choices for these engines. Owing to their low viscosity at low temperatures and limited density and calorific values, they burn clean and remain stable at high temperatures.
Spark-ignited internal-combustion engines (Piston Engines)
This engine is powered by a small piston and used in small aircraft (light aircraft).
Because their pistons work like those used in car engines, the best fuel choice for these engines is the AvGas fuel. Although AvGas varies from the motor gasoline on many fronts, they are similar in their functionalities and how they influence their respective engines.
Prospects for Jet Fuel
The world is evolving on all frontiers, and aviation is not showing signs of lagging behind. Growing technological advances, as well as the need to solve the ecological problems of fossil fuel, have led to interesting prospects for jet fuel. The emergence of bio-fuel and speculations over the possibility of solar-powered airplanes have become hot topics amongst aviation enthusiasts.
Scientists are in the race to provide an effective alternative to conventional jet fuel as we know it. A product of this race is the ion-propelled plane, which adopts an electrical phenomenon known as the ion wind effect to generate thrust without moving parts.
This idea has already received a patent and is registered under the US Patent No. 10 119 527. With all these interesting innovations, I believe it is safe to say that the future of aviation is bright and beautiful. Who knows, we could soon be cruising in ‘star-trek-like’ shuttles!
Summary
In all, it is conclusive to establish the fact that not all airplanes use the same fuel. An understanding of this fact alone broadens our general perspective on planes and allows us to interact more accurately and factually with the prospects of aviation.
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