- Exam Snapshot: The Numbers You Must Know
- Domain 1: Introductory and General Requirements
- Domain 2: Common Maintenance Practices
- Domain 3: Fundamentals of On-Equipment Maintenance
- Domain 4: Aircraft Fundamentals
- Registration, Fees, and Retake Mechanics
- Who Actually Hires AET Holders
- The Final-Week Review Plan
- Frequently Asked Questions
- The AET exam has 90 multiple-choice questions, a 2-hour limit, and no hands-on component.
- You need a 73% passing score across four domains, not per-domain minimums.
- The $175 fee is charged for every attempt - retakes are unlimited but never free.
- Certification lasts 5 years, after which renewal or specialty endorsement paths apply.
Exam Snapshot: The Numbers You Must Know
Before diving into content, memorize the mechanics. These are the facts examiners assume you already know walking in, and they're the same facts that trip up candidates who show up unprepared for the format rather than the material.
| Detail | Fact |
|---|---|
| Governing standard | ASTM F3245-25 (maintained by ASTM Committee F46 / NCATT) |
| Exam administrator | SpaceTEC Partners' Credential Testing Services |
| Format | Computer-based, 90 multiple-choice questions |
| Time limit | 2 hours |
| Passing score | 73% |
| Fee | $175 per attempt |
| Hands-on component | None |
| Certification term | 5 years |
| Testing options | Approved test sites or remote proctoring |
Notice what's absent from that table: prerequisites. There's no age, education, training, career field, or experience requirement to sit for the AET exam. If you want the full eligibility picture, the AET requirements guide covers it, but the short version is that anyone can register and test.
Domain 1: Introductory and General Requirements
This domain sets the foundation - safety culture, documentation discipline, and the regulatory language that runs through every other domain. It's less about memorizing part numbers and more about understanding how the aviation maintenance world operates.
Domain 1: Introductory and General Requirements
Candidates must understand the regulatory and procedural backbone of aircraft electronics work before touching hardware-specific content.
- Maintenance documentation and recordkeeping expectations
- Safety practices, hazard communication, and workplace protocols
- General industry terminology and role definitions used across the field
- Foundational understanding of how certifications like AET fit into the broader maintenance ecosystem
Questions here often read like scenario-based judgment calls rather than pure recall. If a term or acronym feels unfamiliar, don't skip it - the exam domains guide breaks each of these four areas down further with subtopic detail.
Domain 2: Common Maintenance Practices
Domain 2 is where hand-skills knowledge gets tested on paper. You won't physically crimp a connector or solder a joint during the exam, but you'll be asked questions that assume you've done it - or at least understand the correct procedure well enough to identify errors in someone else's work.
Domain 2: Common Maintenance Practices
Covers the physical techniques and standards technicians apply across virtually all aircraft electronics tasks.
- Wiring, termination, and connector practices
- Soldering standards and inspection criteria
- Tool usage, calibration awareness, and proper handling procedures
- Static-sensitive device precautions and general workmanship standards
Key Takeaway
Domain 2 questions frequently present a "which of these is done correctly" scenario. Study workmanship standards as procedures with defined right and wrong steps, not as loose concepts.
Domain 3: Fundamentals of On-Equipment Maintenance
This is the troubleshooting-and-diagnostics domain. It tests whether you can reason through a malfunction using test equipment, schematics, and systematic elimination rather than guesswork.
Domain 3: Fundamentals of On-Equipment Maintenance
Focuses on diagnosing, testing, and maintaining installed equipment using proper methodology.
- Use of multimeters, signal generators, and other common test equipment
- Reading and interpreting wiring diagrams and schematics
- Fault isolation logic and systematic troubleshooting sequences
- Preventive maintenance concepts applied to installed avionics equipment
Many candidates underestimate Domain 3 because it feels the most "practical," yet on a multiple-choice exam it's tested through diagrams and written fault descriptions rather than a physical bench. Practicing with realistic question formats matters more here than in any other domain - the AET study guide walks through how to simulate that experience before test day.
Domain 4: Aircraft Fundamentals
The final domain zooms out from bench-level electronics to the aircraft as a whole system - how airframes, powerplants, and avionics integrate, and how electrical systems interact with everything else on board.
Domain 4: Aircraft Fundamentals
Tests broad, systems-level knowledge of how an aircraft's electrical and mechanical components work together.
- Basic aircraft structures and systems terminology
- Electrical power generation, distribution, and load management concepts
- Interaction between avionics systems and other aircraft subsystems
- General aerodynamic and mechanical principles relevant to system integration
Because Domain 4 pulls together threads from the other three, it's a good final review area rather than a starting point - reinforce it after you've built the technical vocabulary from Domains 1 through 3.
Registration, Fees, and Retake Mechanics
The business side of the AET exam is straightforward, but the details matter for anyone budgeting or scheduling around it.
- Cost: $175 per exam attempt, charged again for every retake - there's no discounted resit rate.
- Scheduling: Test at an approved physical testing site or remotely via proctoring, whichever fits your location and preference.
- Attempts: Unlimited retakes are allowed, so a failed attempt doesn't end your path to certification, only your wallet takes the hit.
- Validity: Certification is valid for 5 years, after which renewal or continued-competency steps apply.
- After passing: AET holders can pursue specialty endorsements layered on top of the core credential.
For a full line-item breakdown of what you'll spend from registration through retesting, see the AET certification cost guide. And if you're still deciding whether the numbers justify the investment, the ROI analysis tackles that question directly.
Who Actually Hires AET Holders
The AET credential is built for people working on or entering roles involving aircraft electrical and electronic systems - not just those with "avionics technician" on a business card. Because the exam has zero prerequisites tied to career field, it draws candidates from several adjacent paths:
- Avionics and electronics technicians at MRO (maintenance, repair, and overhaul) facilities
- Airline and charter operator maintenance teams
- Military electronics personnel transitioning to civilian aviation careers
- Manufacturing and installation technicians working on aircraft wiring harnesses and systems
- Technical school graduates seeking an industry-recognized credential before their first aviation job
Employers value AET because it's standardized under ASTM F3245-25 rather than proprietary to one company or training program, making it portable across employers. If you're evaluating career direction, the AET jobs overview and AET salary guide go deeper into where this credential tends to open doors.
Key Takeaway
You don't need current aviation employment to sit for the AET exam - many candidates use it as a credential to break into the field, not just to formalize existing experience.
The Final-Week Review Plan
Generic study techniques only matter if they're mapped to AET's specific structure. Here's how to spend the last stretch before test day, assuming you've already worked through full content once using the AET study guide.
Domains 1 & 2 Consolidation
- Drill terminology and documentation scenarios from Domain 1
- Rehearse workmanship standards and "correct vs. incorrect procedure" questions from Domain 2
Domains 3 & 4 Consolidation
- Practice reading wiring diagrams and fault-isolation logic for Domain 3
- Review systems-integration concepts and electrical distribution basics for Domain 4
Full-Length Simulation
- Take timed practice exams matching the 90-question, 2-hour format
- Identify the domain producing the most misses and do one final targeted pass
Running full practice sets under real exam conditions on our practice test platform is the closest you can get to test-day pacing before you actually sit for it. It also surfaces which domain still needs attention - often more accurately than self-assessment alone.
Frequently Asked Questions
AET stands for Aircraft Electronics Technician. If you want the full breakdown of the term and how it's used across the industry, see AET Meaning or What Does AET Stand For?
No. The AET exam is entirely computer-based with 90 multiple-choice questions and no practical or bench-testing component.
Retakes are unlimited, but each attempt requires paying the $175 exam fee again - there's no reduced-cost retest option.
No. The exam is open to candidates regardless of age, education, training, career field, or experience, as detailed in the AET requirements guide.
The certification has a 5-year term. Holders may also pursue specialty endorsements after passing the core exam, extending the credential's value without starting over.
Keep this page bookmarked as your quick-reference sheet, but don't treat it as a substitute for full content review. Pair it with the domain-specific detail in the exam domains guide and timed repetitions on our practice tests to turn these facts into exam-day speed.