Fuel Systems & Aircraft Plumbing Flashcards

What is the purpose of a fuel crossfeed system on a multi-engine aircraft?

Answer: To feed both engines from either tank to manage fuel load or feed a live engine from any tank after an engine failure

A crossfeed system allows either engine to draw from any tank, balancing fuel loads and enabling a surviving engine to draw from the opposite side's tank after an engine failure.

Aircraft fuel quantity gauges are required by FAR to be accurate to within what tolerance?

Answer: They must only be accurate when reading empty (zero fuel)

FAR 23.1337 requires fuel quantity gauges to be accurate only at the empty (zero) position; at all other quantities, accuracy is advisory and may vary.

What type of material is prohibited for use in aircraft fuel system tubing due to incompatibility with aviation fuels?

Answer: Galvanized steel tubing

Galvanized steel is prohibited in fuel systems because zinc from the galvanizing reacts with tetraethyl lead in AVGAS to form lead compounds that clog filters and damage fuel system components.

When is it mandatory to bond and ground an aircraft during fueling?

Answer: Always, before fueling begins, to prevent static discharge ignition of fuel vapors

Bonding and grounding are always required before fueling to equalize static electrical charges and prevent sparks that could ignite fuel vapors.

What is the correct tube material for a high-pressure aircraft fuel line (above 1,500 PSI)?

Answer: Corrosion-resistant steel (CRES / stainless steel) or titanium

High-pressure fuel lines require CRES (stainless steel) or titanium tubing for the strength and corrosion resistance needed at pressures above 1,500 PSI.

A flexible fuel hose assembly should be replaced if it shows:

Answer: Blistering, cracking, collapse under load, or has exceeded its calendar life limit

Flexible hoses must be replaced if they exhibit blistering, cracking, inner tube collapse, chafing through to reinforcement, or if the calendar service life has expired.