Refuelling - Fuel Systems - Airframes & Aircraft Systems #68

Summary

This lesson covers aircraft refueling methods, emphasizing safety regulations. Light aircraft use the over-wing method, while most jets are pressure refueled through underwing points. The script details refueling controls, tank capacities, and safety measures, including no smoking, proper bonding, and fire precautions. It also addresses refueling with passengers aboard, highlighting the need for qualified supervision and emergency preparedness.

Takeaways

• 🛩 Light aircraft are refueled using the over-wing method by removing filler caps and pumping fuel into the tanks.
• ✈️ Modern jet engine aircraft are typically pressure refueled through underwing refuel and D fuel coupling points.
• 🚫 Before refueling, fueling zones must be established to ensure safety, with restrictions on smoking, flash photography, and electronic flashes.
• 🔌 Aircraft must be bonded to the fueling equipment to prevent electrical sparks during refueling.
• 🔧 Each fuel tank has a three-position refuel valve switch, which can be controlled automatically or manually.
• 💡 The high-level light indicates when the tank is full, and the refueling valve is closed to prevent overfilling.
• 🔄 The D fuel transfer valve allows for fuel to be pumped back into the tanker from the aircraft's tanks.
• ⚠️ Special precautions are necessary during refueling, such as moving ground equipment clear if the aircraft settles and not operating main engines.
• 🚫 Aircraft should not be refueled near radar equipment or if the landing gear is overheated.
• 🛂 Passengers can remain on board during refueling under certain conditions, with specific safety procedures in place.

Q & A

What is the over-wing method for refueling light aircraft?

The over-wing method involves removing the tank filler caps in the wing upper surface and pumping fuel from the dispensing unit into the tanks.

How are modern jet engine aircraft typically refueled?

Modern jet engine aircraft are pressure refueled from hydrants or delivery vehicles through underwing refuel and D fuel coupling points, controlled from an external refill control panel.

What is indicated on the gauge of the delivery vehicle during refueling?

The quantity of fuel delivered in liters or gallons is indicated on a gauge on the delivery vehicle.

What does the blue high-level light on the control panel signify?

The blue high-level light illuminates to indicate that the high-level flow switch has operated to close the refill valve because the tank is full.

What are the three positions of the refuel valve switch on aircraft?

The three positions of the refuel valve switch are normal, open, and shut. In normal, the tank refill valve is controlled by the automatic refueling computer; open opens the refueling valve unless the tank is full; and shut keeps the associated refuel valve closed.

What is the purpose of the test switch on the refueling control panel?

The test switch is a three-position switch used to test the operation of the high-level float switches or volumetric chopped-off units to ensure they are serviceable.

What safety measures must be in place before refueling an aircraft?

Before refueling, fueling zones must be established, no smoking or use of flash equipment is allowed, and the aircraft must be bonded to the fueling equipment to prevent electrical sparks.

What are the restrictions within the fueling zones?

Within fueling zones, there must be no smoking, no use of photographic flashbulbs or electronic flash equipment, and only authorized personnel and vehicles should be allowed.

Why is it important to follow the correct refueling sequence for aircraft tanks?

The correct refueling sequence is important to avoid adversely affecting the aircraft's center of gravity position, especially if the aircraft has a vertical or horizontal stabilizer tank.

Under what conditions are passengers allowed to remain on board during refueling operations?

Passengers may remain on board during refueling operations if the aircraft has more than 20 seats, and if F gas or Jet B is not being used. Additionally, one qualified person must be present to handle emergency procedures, and passengers must be informed that refueling is taking place.

What should be done if fuel vapor is detected inside the aircraft during refueling?

If fuel vapor is detected inside the aircraft during refueling, fueling must be stopped immediately, and appropriate safety measures must be taken.