Electrical Systems & Avionics Flashcards

What is the purpose of a bus bar in an aircraft electrical system?

Answer: To distribute electrical power to multiple circuits from a common point

A bus bar serves as a common distribution point that connects multiple electrical circuits to a power source.

When an aircraft generator fails to produce voltage, which component should be checked first?

Answer: The generator brushes and slip rings

Worn or dirty brushes are a common cause of generator output failure and should be inspected first.

What does the term 'floating ground' indicate in aircraft wiring troubleshooting?

Answer: A ground wire with excessive resistance or an open circuit

A floating ground refers to a ground connection that has high resistance or is completely open, preventing proper circuit completion.

What type of wire insulation is required in areas of an aircraft exposed to fuel or hydraulic fluid?

Answer: Fluid-resistant insulated wire such as PTFE or nylon-jacketed

Wiring in areas exposed to fluids must use fluid-resistant insulation like PTFE (Teflon) or nylon jacketing to prevent degradation.

Which instrument uses a Wheatstone bridge circuit to measure fuel quantity?

Answer: The capacitance-type fuel quantity system

Capacitance-type fuel quantity systems use a Wheatstone bridge to compare capacitance values and determine fuel quantity accurately.

What is the correct method for splicing aircraft wiring when a connector is not available?

Answer: Use a solderless crimp splice with approved heat-shrink tubing

FAA-approved crimped splices with heat-shrink tubing are the correct method; wire nuts and tape are not approved for aircraft.

A pilot reports intermittent compass deviation when the landing gear is cycled. What is the most likely cause?

Answer: A chafed wire in the landing gear circuit creating electromagnetic interference

A chafed wire can create intermittent shorts that generate magnetic fields near the compass, causing temporary deviation.