Avionics Engineer Interview Questions UK: 8 Real Questions and What Interviewers Want

Most Avionics Engineer interviews in the UK follow a pattern, and knowing it beats guessing. Below are eight questions from our bank of 12, each with a note on what the interviewer is really after.

Eight Avionics Engineer interview questions, and what the interviewer is thinking

1. Explain ARINC 429 and how it differs from MIL-STD-1553 and AFDX or ARINC 664.

Why they ask: They want to confirm knowledge of the main avionics data buses.

2. Describe your fault-finding method on an avionics defect, from the pilot's report to the fix.

Why they ask: They want to see a disciplined troubleshooting process and documentation use.

3. What is the Part-66 B2 licence, and how does the approval to release an aircraft to service work in a Part-145 organisation?

Why they ask: They want to check you understand the UK and EASA-style maintenance regulatory framework.

4. How do you inspect and repair aircraft wiring, and what is EWIS?

Why they ask: They want to see practical wiring knowledge, a major source of defects.

5. What environmental and qualification factors apply to avionics equipment, such as DO-160, EMI and lightning protection?

Why they ask: They want to test knowledge of how avionics is qualified and why installation practice matters.

6. You have a flight due in 40 minutes and a fault message on a flight control display. The minimum equipment list may allow dispatch. What do you do?

Why they ask: They want to see the balance between operational pressure and airworthiness.

7. Tell me about a time you diagnosed a difficult electrical or avionics fault.

Why they ask: They want proof of practical troubleshooting under real constraints.

8. What does an avionics engineer do, and what qualities does the job demand?

Why they ask: They want to check you understand the role and its disciplines.

A sample answer to question 1

Explain ARINC 429 and how it differs from MIL-STD-1553 and AFDX or ARINC 664.

ARINC 429 is a simple, unidirectional serial bus: one transmitter talks to up to twenty receivers over a twisted shielded pair, using 32-bit words that contain a label, source and destination identifier, data and a parity bit, at either 12.5 or 100 kilobits per second. It's reliable and easy to fault-find, but a separate bus is needed for each direction and transmitter. MIL-STD-1553 is a bidirectional, command-response bus at 1 megabit per second, controlled by a bus controller that polls remote terminals, with a monitor optionally listening, and it's very deterministic and robust, used mostly in military aircraft. AFDX, based on ARINC 664 Part 7, is an avionics version of switched Ethernet, with virtual links, bandwidth allocation and redundant networks, giving high speeds of 100 megabits per second and far lower wiring weight, as on the A380 and 787. When troubleshooting, I'd use a bus analyser or the aircraft's built-in test equipment to check data integrity, label content, signal levels and termination, depending on the bus involved.

Common mistake to avoid: Mixing up the buses; Only reciting definitions with no practical use

Want the rest?

Full model answers, key points and common mistakes for all 12 questions are on the Avionics Engineer interview questions page. The first five are free, no sign-up needed.