Aircraft Fueling and Defueling Procedures

Maintenance crews are often tasked with carrying out a number of standard aircraft safety procedures, two of which include fueling and defueling. These procedures vary from aircraft to aircraft, wherein there may be a prescribed sequence to follow when performing such tasks to prevent damage to the airframe or other structures. As such, making sure that the proper procedures are taking place prior to fueling is paramount.

To begin, fueling procedures should only take place outside, never in the hangar where fuel vapors can accumulate and increase the risk of an accident. There are two types of fueling processes: over-the-wing refueling and pressure refueling. The former is achieved by removing the fuel tank cap on the surface of the wing or fuselage and inserting the fueling nozzle into the opening, allowing fuel to be pumped into the tank. When the tank is full, the cap should be secured.

Pressure refueling, on the other hand, occurs at the bottom, front, or rear of the fuel tank. The pressure refueling nozzle is fastened onto the fueling port at the aircraft fueling station. Fuel is then pumped into the aircraft via this secured connection. Meanwhile, gauges should be strictly monitored to confirm when the tanks are properly loaded. Within some aircraft, an automatic shutoff system may be present, closing the fueling valve once the tanks are full. With pressure refueling, one must ensure that they can identify the various components within the fueling valve assembly. As some valves are more sensitive than others, refueling personnel should be guided through the correct use of each.

Regardless of the fueling procedure being carried out, each should be handled with care. Firstly, it is critical that the correct quantity of fuel be put into the aircraft. More than that, ensuring that the type of fuel used is compatible with the aircraft model at hand is important. The pilot in command or other personnel should consult the manufacturer’s maintenance instruction manual for such information.

Another important aspect of fueling and defueling procedures includes keeping a keen eye on cleanliness. With this in mind, the area adjacent to the fill port should be clean when refueling over the wing. To ensure that outside contaminants do not make their way into the filling port, the cap should only be removed during refueling or defueling. Additionally, internal aircraft structures are much more delicate than the fuel nozzle; thus, you must make sure that the neck of the nozzle does not hit the bottom, causing damage to the tank or aircraft skin.

When fueling from a fuel truck, precautions should be taken. For example, visually inspecting the fuel for debris or particulate matter is paramount. If turbine fuel is being used, the fuel must settle for a few hours. Moreover, the aircraft should approach the fueling vehicle slowly and park parallel to the wings or in front of the fuselage if feasible. Once parked, set the parking brake, chock the wheels, and connect the static bonding cable from the truck to the aircraft. Typically, the cable can be found on a reel mounted on the truck.

Usually carried out for maintenance purposes or to check for contamination, defueling follows the same precautions and procedures required for fueling. As such, defueling must take place outside and fire extinguishers should be on hand. Also, bonding cables should be connected to protect against static electricity buildup. Similar to fueling, there is a sequence of procedures that must be carried out to avoid damage. If defueling is taking place due to contamination, the fuel should be disposed of properly. In contrast, good fuel should be stored as per the manufacturer’s recommendations.

Lastly, due to the combustible nature of fuel, there is an increased risk for fire during fueling and defueling. Therefore, one must avoid open flames near the area where such procedures are being carried out. Likewise, the operation of electrical devices should be avoided and the use of radio and radar is prohibited. That being said, if you find yourself in need of fuel gauges, refueling nozzles, refueling pumps, or other related equipment required for fueling and defueling, rely on Aerospace Exchange.

Aerospace Exchange is a leading supplier of aircraft engines and their various components. With over 2 billion items in our inventory, we can fulfill all of your operational needs with ease. Kickoff the procurement process with a competitive quote which you may access through our Instant RFQ service, and see how Aerospace Exchange can serve as your strategic sourcing partner.