CAT Avionics and Electrical Systems 1

Question 1

What does the acronym 'EFIS' stand for in aircraft avionics?

Accepted Answer

Electronic Flight Instrument System

Answer

EFIS stands for Electronic Flight Instrument System, which replaces traditional analog gauges with digital displays for flight data.

Question 2

What is the standard DC voltage used in most commercial and military aircraft electrical systems?

Accepted Answer

28V DC

Answer

28V DC is the aviation standard for aircraft DC electrical systems, as specified in MIL-STD-704 and related airworthiness standards.

Question 3

At what frequency do most aircraft AC electrical systems operate?

Accepted Answer

400 Hz

Answer

Aircraft AC systems operate at 400 Hz, which allows transformers and motors to be significantly smaller and lighter than 60 Hz ground-based equipment.

Question 4

What is the primary function of an Integrated Drive Generator (IDG) on a commercial aircraft?

Accepted Answer

Produces constant-frequency AC power from variable engine speeds

Answer

An IDG incorporates a Constant Speed Drive (CSD) to maintain 400 Hz AC output regardless of engine RPM fluctuations.

Question 5

Which data bus standard is used in modern aircraft such as the Boeing 787 for high-speed Ethernet-based avionics networking?

Accepted Answer

ARINC 664 (AFDX)

Answer

ARINC 664 (AFDX – Avionics Full-Duplex Switched Ethernet) provides high-bandwidth, deterministic data networking used in the B787 and A380.

CAT - Certified Aerospace Technician Practice Test

CAT - Certified Aerospace Technician Practice Test

CAT Avionics and Electrical Systems 1