SkyDrill

Static bonding during over-the-wing refueling

Aviation Mechanic Airframe (AMA) practice question 6 of 12 on Aircraft Fuel Systems. ACS element AM.II.J.K4 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic Airframe (AMA) practice mode.

Question bank updated 2026-09-22

QUESTIONDuring over-the-wing refueling, when must the static bonding wire on the fueling nozzle be attached to the aircraft?

  1. AAfter the nozzle is seated in the fill port
  2. BOnly when fueling a turbine-powered aircraft
  3. CBefore the fuel cap is opened
Show the answer and explanation

Correct answer: C. Before the fuel cap is opened

  • A — incorrect Waiting until the nozzle is seated leaves the open fill port exposed to a static discharge while vapors are escaping.
  • B — incorrect Bonding is required for aviation fuel handling generally, not only for turbine fuel, because both fuels produce ignitable vapor.
  • C — correct Aviation fuel nozzles carry static bonding wires that must be attached to the aircraft before the fuel cap is opened.

BACKGROUND

Aircraft are fueled outside rather than in a hangar, where vapors can accumulate. Over-the-wing refueling opens a cap on the upper wing or fuselage surface and pumps fuel through a nozzle, while pressure refueling uses a nozzle locked onto a port at the bottom, front, or rear of the tank. Before an over-the-wing cap is opened, the nozzle's static bonding wire is attached to the aircraft, and the cap is opened only when the operator is ready to dispense fuel. The area next to the fill port and the nozzle itself are cleaned first to keep solid contaminants out. The nozzle is inserted with care and not pushed deep enough to hit bottom, which could dent the tank or the skin of an integral tank.

STUDY TIP

Remember the order of events for over-the-wing fueling: clean, bond, open, insert, fuel, secure the cap.

KEY POINTS

  • Bond the nozzle to the aircraft before opening the fuel cap.
  • Fuel outside, never in a hangar where vapors collect.
  • Do not let the nozzle neck bottom out in the tank.

SOURCES

  • sources/ama-airframe/ch14.txt, "Fueling"
Practice the Aviation Mechanic Airframe (AMA) test →Timed 100-question exam, by ACS area, or review your misses. Free.
MORE ON AIRCRAFT FUEL SYSTEMS

SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-31B Aviation Maintenance Technician Handbook – Airframe, and 14 CFR part 43. Regulations and handbooks are revised; confirm details against the current edition.