AME - Aircraft Maintenance Engineer Aircraft Electrical Systems Questions and Answers

Question 1

What is the primary function of a Constant Speed Drive (CSD) unit in an aircraft's AC electrical system?

Accepted Answer

To convert variable engine RPM into a constant generator RPM.

Answer

To rectify alternating current (AC) to direct current (DC).

Answer

To regulate the voltage output of the generator.

Answer

To act as a circuit breaker in case of an electrical fault.

Question 2

During a routine inspection of a 24-volt lead-acid battery, an AME notices a significant difference in specific gravity readings between individual cells (e.g., one cell is 1.275 while another is 1.220). What is the most appropriate action?

Accepted Answer

Replace the battery as it is likely nearing the end of its service life.

Answer

Top off the low cell with distilled water and return to service.

Answer

Charge the battery and re-check the specific gravity.

Answer

Add sulfuric acid to the low cell to equalize the specific gravity.

Question 3

In accordance with 14 CFR Part 25, if a fuse is essential for safety in flight and is accessible to the flight crew, what is the minimum number of spare fuses that must be carried on board?

Accepted Answer

At least 50% of the number of fuses of each required rating.

Answer

One spare for each essential fuse.

Answer

At least 25% of the number of fuses of each required rating.

Answer

A quantity sufficient to replace all essential fuses once.

Question 4

Which of the following describes a 'trip-free' circuit breaker?

Accepted Answer

A circuit breaker that will open a circuit even if the operating control is held in the 'ON' position.

Answer

A circuit breaker that can be reset remotely from the cockpit.

Answer

A circuit breaker that requires a special tool to be reset.

Answer

A circuit breaker that cannot be manually reset until it has cooled down.

Question 5

An aircraft is being prepared for flight at a remote station without ground power available. The AME needs to power the ground handling bus to operate the cargo bay lights and refueling system. Which power source would typically be used in this scenario?

Accepted Answer

The Auxiliary Power Unit (APU) generator.

Answer

The main aircraft battery via an inverter.

Answer

A Ram Air Turbine (RAT).

Answer

The main engine-driven generators.

Question 6

When selecting the proper wire size for an electrical installation in an aircraft, which of the following is a critical factor according to the American Wire Gauge (AWG) standard?

Accepted Answer

The wire's cross-sectional area.

Answer

The color of the wire insulation.

Answer

The wire's flexibility rating.

Answer

The brand of the wire manufacturer.