Aircraft fuel tanks are a major component of aircraft fuel systems.
Fuel systems differ enormously from aircraft to aircraft because of the relative size and complexity of the aircraft in which they’re put in. In essentially the most primary form, a fuel system will include a single, gravity feed fuel tank with the related fuel line connecting it to the aircraft engine. In a modern, multi-engine passenger or cargo aircraft, the fuel system is prone to comprise of a number of fuel tanks that could be positioned within the wing or the fuselage (or both) and, in some instances, within the empange.
Every tank will potentially be geared up with internal fuel pumps and have the associated valves and plumbing to feed the engines, enable refuelling and defueling, isolate the person tanks and, in some functions, enable fuel dumping or for optimization of aircraft centre of gravity.
Types of Aircraft Fuel Tanks:
Aircraft usually use four forms of fuel tanks: integral, rigid removable, bladder, and tip tanks.
- Integral tanks are areas contained in the aircraft construction which have been sealed to permit fuel storage. An instance of this kind is the “wet wing” generally utilized in larger aircraft. Since these tanks are a part of the aircraft construction, they can’t be eliminated for service or inspection. Inspection panels should be offered to permit internal inspection, repair, and overall servicing of the tank.
Most massive transport aircraft use this system, storing fuel within the wings, belly, and generally tail of the airplane.
- Rigid removable tanks are put in a compartment designed to accommodate the tank. They’re
usually of metal construction and could be eliminated for inspection, substitute, or repair. The aircraft doesn’t depend on the tank for structural integrity. These tanks are generally present in smaller common aviation aircraft, such as the Cessna 172.
- Bladder tanks, or fuel cells, are augmented rubberized bags put in in a section of aircraft structure designed to accommodate the load of the fuel. The bladder is rolled up and put in into the compartment by means of the fuel filler neck or access panel and is ensured by way of metal buttons or snaps contained in the compartment. Many high-performance light aircraft, helicopters, and a few smaller turboprops use bladder tanks. One main downside to this sort of tank is the tendency for supplies to work harden by way of extensive use, making them brittle inflicting cracks. One major plus aspect is the ability to make use of as much of the aircraft as feasible to store fuel.
Many aircraft designs function fixed tip tanks mounted at the end of each wing. The load of the tanks and fuel counteract wing bending loads throughout manoeuvres and cut back fatigue on the spar structure.
Combat aircraft and helicopters usually make use of a self-sealing fuel tank. Fuel tanks have been involved in aviation disasters, being the reason for the accident or worsening it (fuel tank explosion).
Safety of Fuel Tanks:
Appropriate design and construction of a fuel tank play a significant function in the safety of the system of which the tank is part. Generally, intact fuel tanks are very safe, because the tank is filled with fuel vapour/air mixture that’s effectively above the flammability limits, and thus cannot burn even when an ignition supply was present (which is limited).
Bunded oil tanks are used for cautiously storing domestic heating oil and different hazardous supplies. Bunding is usually required by insurance corporations, rather than single skinned oil storage tanks.
A number of systems, corresponding to BattleJacket and rubber bladders, have been developed and deployed to be used in protecting (from the explosion brought on by enemy fire) the fuel tanks of military vehicles in battle zones.
Placement of Fuel Tanks:
On passenger planes, fuel tanks are sometimes built-in into the wings, and when there are also tanks contained in the body of the aircraft, the wing tanks are used preferentially. The position reduces the stress on the wings throughout take off and flight, by placing the heavy fuel directly contained in the supply of lift.
Placing tanks in the primary wings rather than close to the tail or nose additionally reduces the amount of weight that’s off-centre from the airplane’s centre of gravity, and which changes because it flies and which might make the plane much less efficient by requiring increased use of elevators. Given their irregular form and lack of windows, wings are sometimes unusable for the storage of cargo or seating of passengers. However, their hollow construction makes in-wing fuel storage possible and efficient use of space;
the presence of structural spars in “wet wing” tanks reduces sloshing. Placement of fuel tanks within the wings also strikes them farther from passengers and crew within the event of a leak or explosion.
1. What are aircraft fuel tanks made of?
They are typically made of metal, plastic or fibreglass construction, and may be removed for inspection, replacement, or repair. Rigid removable tanks are not relied on for the aircraft’s structural integrity. These tanks are commonly found in smaller general aviation aircraft, such as the Cessna 172.
2. Which gas is used for purging an aircraft fuel tank?
An inerting system decreases the probability of combustion of flammable materials stored in a confined space, especially a fuel tank, by maintaining a chemically non-reactive or “inert” gas, such as nitrogen, in such a space. “Inerted” fuel tanks may be used on land, or aboard ships or aircraft.
3. What is an integral fuel tank?
Integral tanks are areas inside the aircraft structure that have been sealed to allow fuel storage. An example of this type is the “wet wing” commonly used in larger aircraft. Since these tanks are part of the aircraft structure, they cannot be removed for service or inspection.
4. Why are aircraft fuel tanks vented?
The venting system also helps to prevent fuel evaporation. As the aircraft climbs due to the reduction in pressure, the boiling point of fuel decreases. This evaporates fuel. The duct in the picture allows ram air to enter the fuel vent system, which pressurises the fuel tanks and avert the evaporation of fuel.