Fuel Servicing

AVGAS

  • Aviation gasoline (AVGAS) is used in reciprocating engines

  • AVGAS is identified by red, blue, green, and purple colors according to fuel grade

    • Tetra-ethyl lead is a common additive used as anti-knock agent

    • Other additives include gum deposits, and corrosion and ice inhibitors

Jet Fuel

  • JET A fuel is used in turbine engines

  • Turbine fuels are a yellow or straw color

    • Prist is a common anti-icing additive, but a biocide may also be mixed in to prevent microbial growth

-NEVER mix AVGAS and turbine fuel

Figure 1

Fuel contaminants

-Contamination in aviation fuel is anything in the fuel that is not supposed to be there

  • Controlling contamination is extremely important to prevent engine failure and loss of life

  • Best method = prevent introduction to fuel system

  • Keep fuel dry; use filters, screens, and separators

  • Other fueling concerns: Static electricity buildup, breathing fuel vapors, fuel spill on clothing or skin

Types of Contaminants

-The most common contamination is servicing with the wrong type of fuel

  • AVGAS in turbines leave lead deposits on blades

  • Reciprocating engines will not run on turbine fuel

-Other contaminants include water, solids, and microbial growth

Fueling Procedures

-Two types of fueling procedures:

  • Smaller aircraft use over-the-wing method

  • Larger aircraft use single point fueling method

    • Utilizes a receptacle to fill all tanks from one point

-Prior to refueling, turn off all electrical systems and devices, connect static ground wires, ensure correct fuel type, and equip PPE.

  • Do not fuel if lightning is near (5 mi or 500ft from operating radar)

Figure 2

Defueling Methods and Precautions

  • Gravity defueling or pumping

    • Always follow safety precautions when defueling

    • Make sure aircraft and defueling equipment are grounded with correct fire extinguisher on hand

    • Use caution not to empty the forward tanks first when defueling

Figure 3