Avionics and Electrical Systems Flashcards

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

Answer: Electronic Flight Instrument System

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

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

Answer: 28V DC

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

At what frequency do most aircraft AC electrical systems operate?

Answer: 400 Hz

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

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

Answer: Produces constant-frequency AC power from variable engine speeds

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

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

Answer: ARINC 664 (AFDX)

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

Which navigation system uses a network of VHF ground-based transmitters to provide azimuth information to aircraft?

Answer: VOR

VOR (VHF Omnidirectional Range) uses ground station radio transmissions to provide magnetic bearing information to airborne receivers.

What is the purpose of an aircraft Ground Fault Interrupter (GFI) circuit?

Answer: To detect and interrupt unintended leakage currents flowing to the airframe

A GFI detects small leakage currents flowing to the airframe structure and interrupts the circuit to prevent shock hazards or fire.