Grounding ensures electrical continuity between the aircraft and the earth. Static electricity resulting from the flight or the environmental conditions on ground (wind with dust, sand, etc...) is discharged to the earth through the tires.

Grounding an airplane during fueling is a critical safety measure used to prevent electrostatic discharge (sparks) from igniting the highly flammable jet fuel vapors. As fuel flows through the hose at high speeds (up to 1,000 gallons per minute), it creates friction, which generates a significant buildup of static electricity on both the fuel truck and the aircraft's skin. Additionally, the air flowing over the wings during flight can leave a plane with a residual static charge. If a spark were to jump between the fuel nozzle and the aircraft's fuel tank port, it could trigger a catastrophic explosion. To prevent this, a "bonding wire" is first connected between the fuel truck and the aircraft to equalize their electrical potential, and a second "grounding wire" is connected to a metal point in the tarmac (the "ground") to dissipate any remaining charge safely into the Earth. In 2026, fueling systems use automated "closed-loop" monitoring to ensure these connections are secure before a single drop of fuel is pumped, making the refueling process one of the most strictly controlled procedures in aviation.