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The Air Fuel Management System of Aircrafts

by Admin on November 1, 2022

Fuel is one of the most essential components of flight operations. iJET provides a classification of aircraft fuel management due to our years of experience in providing clean and reliable airplane fuel.

In almost every industry, setting up sustainability strategies seemed like the most logical solution. In addition, an effective sustainability plan is needed in the aviation sector. It is the most environmentally friendly type of fuel, also known as sustainable aviation fuel (SAF). Compared to conventional jet fuel, it is more environmentally friendly.

As a result of the size and complexity of each aircraft, aircraft fuel system differs greatly from one to the next. Typically, a fuel system will have a single gravity-fed fuel tank connected to a fuel line that feeds the engine. The fuel propulsion system on a modern, multi-engine aircraft will likely contain multiple fuel tanks, located either in the wings or in the fuselage.

Depending on the application, each tank may be equipped with an internal fuel pump, valves and plumbing to feed the engines, allow for refueling and defueling, isolate individual tanks from each other, or allow fuel used in aircraft fuel dumping or the optimization of the aircraft’s center of gravity.

Light Single Engine Aircraft

A single tank fuel system is common on small piston-engine aircraft. Aircraft fuel tanks are more commonly found in the wings of newer aircraft. To control fuel delivery to a single engine, a two tank system requires additional components. It depends on where the fuel tanks are located whether or not boost pumps are incorporated.

Light Twin Engine Aircraft

Fuel systems and their management become more complex when an aircraft adds a second engine. A small multi-engine aircraft may also offer in-tank fuel pumps, an improved fuel quantity indicator system, and fuel crossflow capability. In most cases, refueling is done on a tank-by-tank basis.

Turboprop and Turbojet Aircraft with Multiple Engines

The fuel system of an aircraft will typically change as its size and complexity increase. Among these changes may be increased automation of the system, additional fuel tanks, specific AFM (Active Fuel Management) requirements regarding fuel distribution in flight, and how the tanks should be filled or used in flight in a particular sequence. There is a reliable system indication and alerting system, as well as provisions for single point refueling and defueling, and a provision for fuel dumping and/or center of gravity optimization through fuel movement in flight in larger aircraft.

The Ignition of Fuels

In general, aviation fuels can be classified into two categories: aviation gasoline – commonly abbreviated as “avgas” – and paraffin fuel, which is used by all gas turbine engines.

AVGAS

The quality control of AVGAS is much more rigorous than that of automotive gasoline. AVGAS has an octane rating of 100, which measures how resistant a fuel is to pre-ignition (the chance that combustion occurs before a spark is thrown). When handled improperly, it can ignite at the same flashpoint as automotive gasoline. Almost all aircraft utilizing AVGAS are light aircraft, despite the fact that there are many more aircraft that use it than jet fuel.

Jet Fuels

A jet fuel called Jet A-1 is the most common jet engine fuel in use. Their flashpoint is 38°C, making them kerosene grade fuels. As Jet B has a much lower freezing point, it is a great choice for use in extremely cold conditions. Its flash point (minus 18°C.) is also much lower, making it an excellent choice. There are some fuels that have higher flashpoints and have been developed for specific military applications so that they can provide an additional safety margin. The quality of jet fuel is rigorously tested for impurities, and any fuel that fails is diverted to the ground. A variety of additives are included in aviation fuels. These include corrosion inhibitors, static dissipaters, and anti-freezing agents.

Contributing Factors

With the follow-up of aircraft engineering there are a number of factors that can inhibit the effective planning of preflight fuel, including time constraints, changing weather conditions, poor communication, and complacency on the part of dispatchers or pilots.

Robust Fuel Management in the Company Operations

An Air Operator Certificate (AOC) approval will depend on the content of the Company Operations Manual as specified by the National Aviation Authority (NAA). Regulated requirements may be contained within the National Authority’s Regulations or in separate publications, such as British CAA publication CAP 789 – Operator Requirements and Guidance Material. Either way, the Operations Manual must include specific tenets of the Company fuel policies, which is a crucial aspect of the guidance provided.

  • Minimum contingency fuel quantities and pre-departure fuel usage policy
  • Taxi criteria for single engine aircraft
  • Policy for monitoring and recording fuel consumption
  • In non-standard operations such as remote destinations or long range flights, specify fuel policy
  • The amount of Final Reserve Fuel should be specified by aircraft type
  • Identify actions to be taken if Final Reserve Fuel appears likely to run out
  • Once the Final Reserve Fuel has been exhausted, describe what action should be taken
  • Taking action when there appears to be insufficient fuel to continue the flight
  • The process of declaring a fuel emergency (PAN or MAYDAY)
  • For issues such as the uplift of fuel in excess of basic flight plans
    • Inclimate conditions
    • Delays to be expected
    • Congestion in the airspace
    • Fuel penalties for failure to comply with the Minimum Equipment List (MEL) or Configuration Deviation List (CDL)

iJET provides commercial, cargo, private, and military jet operators worldwide with all types of jet fuel. The best possible rate in the market is available when we refuel your aircraft with Jet A, Avgas, Jet A-1 fuel, and more. Our global network of major and local fuel suppliers ensures we can meet all of your fuel requirements.

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