AET Diagnostic and Testing Tools 3

Question 1

When measuring resistance in an installed aircraft circuit with a digital multimeter, the technician must first:

Accepted Answer

De-energize the circuit and discharge any capacitors

Answer

Measuring resistance in a live circuit will give inaccurate readings and can damage the meter; the circuit must be de-energized first.

Question 2

Which of the following best describes the function of a BITE (Built-In Test Equipment) system?

Accepted Answer

Onboard self-test circuitry that monitors and reports system faults automatically

Answer

BITE is embedded within avionics units to continuously or on-command perform self-tests and store fault codes for maintenance retrieval.

Question 3

A technician uses an oscilloscope to observe a 400 Hz aircraft power bus waveform and notices the top of the sine wave is flattened. This condition is called:

Accepted Answer

Clipping or waveform clipping

Answer

Clipping occurs when a signal exceeds the linear range of a component or supply, causing the peaks to be cut flat.

Question 4

The correct procedure when using a megohmmeter (megger) to test aircraft wire insulation is to:

Accepted Answer

Disconnect components from the wire under test to avoid applying high voltage to sensitive avionics

Answer

Megohmmeter test voltages (typically 500–1000 V) can permanently damage solid-state avionics connected to the wire under test.

Question 5

When calibrating a pressure transducer used in an aircraft fuel quantity system, which test equipment is most appropriate?

Accepted Answer

Dead-weight tester or precision pneumatic pressure calibrator

Answer

A dead-weight tester or precision pneumatic calibrator provides traceable reference pressures needed to verify and adjust pressure transducer accuracy.

(AET) Aircraft Electronics Technician Practice Test

(AET) Aircraft Electronics Technician Practice Test

AET Diagnostic and Testing Tools 3