Do you know how the aircraft is refueled? Is it the same as refueling a car, just opening the fuel tank cap and putting the oil gun in? And what kind of fuel is added to the plane? Is it the same as the oil in the car?
First of all, let’s understand how various oil products are produced.
Production of different fuels:
Petroleum is distilled to obtain gasoline, diesel, and kerosene at different temperatures. Kerosene is stable and efficient, so most aircraft use “aviation kerosene”—you can often smell it when the air-conditioning system is turned on after the plane is ignited.
The type of aviation kerosene used by aircraft is called “Jet A”. There are two types: Jet A and Jet A-1. Jet A has a slightly higher freezing point and is more pure than Jet A-1.
When it comes to the basic refueling methods of aircraft, there are currently two types, gravity refueling and the other is pressure refueling.
Small aircraft are usually refueled using refueling hoses from refueling on the aircraft’s wings. The aviation fuel is transported to the refueling port through the oil pump on the refueling truck,
and the aviation fuel flows into the aircraft fuel tank by gravity.
When it comes to large aircraft, this method of refueling is not suitable. Because large wide-body airliners have a fuel tank capacity of several hundred tons,
it takes a lot of time to refuel only by gravity, so there is a method of “pressure refueling”.
Pressure refueling mainly relies on pressure to add aviation fuel into the fuel tank. This refueling method needs to be refueled with the help of a refueling platform located at the lower part of the leading edge of the wing.
Most refueling systems consist of a refueling hose, a refueling control panel, and a fuel gauge.
How is aviation fuel stored? Since planes have large fuel tanks, where is so much aviation fuel stored when refueling?
When the aircraft is refueled, there is a fuel truck in the picture that drives near the aircraft.
Some friends may be curious: this fuel truck is so small, how much aviation fuel can be added?
In fact, this refueling truck does not store aviation fuel itself. Under the apron of some large airports, many pipelines will be buried to transport aviation fuel.
The pipe network under the apron is under pressure, just like an underground fountain. The aviation fuel is in the oil depot far away, and through the pressure-maintaining pump, every interface of the entire apron pipeline network is under pressure.
At this time, the oil truck can be understood as a “filter”. After the underground aviation fuel is filtered and purified, it can be transported to the fuel tank of the aircraft.
This kind of refueling truck is called a “pipeline fueling truck”. Of course, some airports do not have pipelines under them, so what should they do? At this time, it is necessary to rely on the “tank fuel truck”.
It looks like a sprinkler that we often see on the road, and aviation fuel is stored in a large tank in the car. Its working process is actually similar to that of a pipeline-type refueling truck.
The difference is that the tank-type refueling truck pumps its own aviation fuel, while the pipeline-type refueling truck pumps aviation fuel from underground pipelines.
Due to height restrictions, the tank truck cannot drive under the wings of the plane. The distance from the tanker to the filling port requires dragging the oil pipe.
Smaller airports, or airports built earlier, have no pipelines underground, so tankers can only be used to refuel. Some tankers are very large and can hold dozens of tons of fuel.
Relatively speaking, it is certainly more convenient to have underground pipelines. Because some tankers are too large to run around unsafely. The pump truck is small in size, and the oil pipe has wheels. It is more convenient.
Aircraft refueling operation:
Refueling the aircraft needs to be operated strictly in accordance with the prescribed procedures.
Before refueling the aircraft, the refueling crew must wear a full set of professional work clothes and be fully equipped with safety shoes, goggles, and other equipment.
Next, the refueling crew drives the refueling truck according to the prescribed route and drives smoothly under the wing at a speed of 5 km/h.
At this time, it is necessary to strictly maintain a safe distance from the aircraft and other operating equipment.
In the deafening roar of the aircraft engine, after the aircraft refueling vehicle stops, the first thing to do is to place the wheel chocks to ensure that the vehicle will not move during the refueling process.
The second thing is to connect the static conduction device between the refueling vehicle and the aircraft, which is to eliminate the potential fire hazard caused by static electricity.
Then, the aircraft refueling crew will connect the ground well connector of the refueling vehicle with the well of the underground pipe network on the apron, and set up the on-site warning signs.
At the same time, connect the emergency pull rope to ensure that the fuel source can be cut off the first time in case of an accident.
Subsequently, the aircraft refueling operator operates the lifting platform through the refueling truck and connects the refueling joint of the vehicle to the fuel tank port of the aircraft.
The on-site crew signs the refueling confirmation form, and after checking the refueling amount, the aircraft refueling crew can start the refueling operation.
The above is the knowledge about aircraft refueling, so the seemingly simple refueling actually requires a very strict process.