How the CAET Course Was Built
The CAET course trains entry-level avionics technicians. Nick Brown’s course team, people and AI coding agents, built it to one written method under one subject expert’s review. This site shows that method, the rules behind it, and the lesson parts themselves, live, so you can try them in your browser.
The CAET Course
CAET is the Certified Avionics Electronics Technician certification of the Aircraft Electronics Association (AEA). The course that prepares students for it has 51 lessons and 25 hands-on labs in 14 topic rooms, from Shop Safety to Surveillance. Each lesson is one web page that moves left to right, one idea per page, built to one written standard. Students reach the same lessons through two front doors: a 3D training hangar they walk through in the browser, and a plain course library.
Each one a run of pages in the same order, one idea per page.
Hands-on work on simulated circuits, instruments and a wiring bench.
From Shop Safety and Regulations to Navigation and Surveillance.
From Plan to Lecture
Every lesson goes through the same nine steps. A builder, a person or an AI agent, does the work; the course owner approves the plan, reviews every page and publishes. A page that needs work goes back to the build step until the owner signs it off.
- 1
Plan
The lesson gets its place in the course: its scope, objectives tied to CAET codes, prerequisites and a page plan.
Out: one entry in the course Blueprint
The builder reads the one build standard and walks the approved model lesson. A rebuild lists every part of the old lesson and gets a storyboard approved.
Out: an approved storyboard
Every word of every page is written before anything is built: the label, the plain heading, the goal, the on-screen text, the interaction and the sources.
Out: the page copy file
The words go in a data file, the layouts in templates, and one script assembles the lesson. Working sims are lifted from the old lesson, never redrawn.
Out: the lesson page
Five check questions, one per objective focus. Every wrong option is a real mistake, and every option has one sentence of feedback that teaches.
Out: the lesson’s check file
- 6
Test
Unit tests, a browser test that drives every page on a desktop and a phone, and a person looking at a screenshot of every page.
Out: a review packet
Only the course owner publishes. The preview site is rebuilt from committed files.
Out: the lesson on the preview
The owner reads every page on a phone and writes a squawk, the aviation word for a reported defect, against any page that needs work. Each squawk is fixed and signed off.
A squawk goes back to step 4.
Out: every page signed off
The classroom lecture, two narrated instructors at an animated whiteboard, is re-cut to match the signed-off lesson.
Out: a narrated lecture deck
Ten Rules
Each rule came from a review decision on a real lesson, and each one rests on a principle in the library.
- 1
NEETS-Style Writing
Write like the Navy Electricity and Electronics Training Series (NEETS): state the fact, define the term, show how it is applied. Plain noun headings, no slogans, no em or en dashes. Every term is defined the first time it appears.
Why: plain language and Simplified Technical English. How: the writing rules
- 2
One Idea per Page
Each page names one subject, opens with its point set big, and fits about one and a half phone screens. Key content is never hidden in a drop-down.
Why: cognitive load, segmenting
- 3
An Interaction on Every Page
Every page has at least one interaction or graphical block, never two plain paragraphs in a row. Each interaction must make the student think about the page’s idea, and no two pages in a row use the same one.
Why: the ICAP framework. How: the mixing guide
- 4
Real Documents
Students read the real regulation, safety data sheet, form or FAA figure and tap its parts, instead of reading a summary of it. Every document is credited on the page.
Why: transfer of learning. Try it: the 91.411 demo
- 5
Keep the Real Sims
A rebuilt lesson lifts its working simulations and real schematics from the old lesson. It never replaces them with a drawing. A proof that lost the sims was rejected.
Why: simulation and fidelity. How: the Circuit Lab
- 6
Picture Questions
Where a picture is the skill, the options are pictures: three schematics, three meter faces, three parts, each beside a one-line description.
Why: dual coding. Try it: the picture options demo
- 7
History and Incidents from Official Reports
A person gets a page only when the story carries the concept to the bench. A real accident is told from the official report, with what a technician would have caught, and no blame beyond the report.
Why: learning from incident cases. How: history and incidents
- 8
3D Where Shape Teaches
A 3D model only when turning the part shows what a flat drawing cannot: a generator loop, a micro switch, a gyro that precesses. Each one has view buttons, labels and a still picture for weak phones.
Why: animation, video and 3D. How: 3D in lessons
- 9
Phone First
Every page is tested at 390 pixels wide and looked at: text 16 px or larger, tap targets 44 px or larger, no sideways scroll, and every drag also works by tap and by keyboard.
Why: accessible design. How: the Electric Ink look
- 10
The Reviewer Is the Subject Expert
The course owner, an avionics subject expert, reads every page and writes a squawk against any page that is wrong or unclear. A lesson is done only when every page is signed off.
Why: expert task analysis. How: the Squawk Board
Try the Lesson Parts
Seven parts from real lessons, with the lessons’ own words, running on a dated snapshot of the course’s shared code. Each one has a short note on why it teaches, linked to the principle and the craft note behind it. Every demo works by tap, by keyboard and on a phone.
One-Card Sort
Sort five shop moments into when you open the safety data sheet: before the job, during an exposure or a spill, or after the job.
Open the demo Series CircuitsPicture Options
Pick the drawing that shows a series circuit, from three small schematics, and read the feedback for your answer.
Open the demo Pitot-Static SystemsFlip Cards
Name the part that guards a pitot or static line against water, ice, insects or a blocked port, then turn the card.
Open the demo The Certification ChecksHotspot on a Real Document
Work three lookups on the current text of 14 CFR 91.411, and read what each paragraph means in plain words.
Open the demo Antennas and CoaxProcess Stepper
Step through an antenna installation, with the FAA figure and the advisory circular’s own words for each step.
Open the demo Blocked Ports and Altimeter SettingPredict, Then Reveal
Predict what the airspeed indicator shows with the static line blocked, then see the two pressures behind the reading.
Open the demo Series CircuitsA Paged Lesson
Six pages in the course’s page order (problem, objectives, recall, a concept page, the check and the field card) on the course’s own pager, with a note on each page saying why it is there.
Open the demoTry a Real Lesson
The course runs on a public preview. These lessons show the method at its best, and each link opens the lesson at the page named. The lessons are built for students, so they save your place in your own browser.
Safety Data Sheets
The approved model lesson, 23 pages. Read a real Safety-Kleen safety data sheet, section by section, with job lookups.
Open at “Reading” Regulations and RecordsThe Certification Checks
Tap each paragraph of the current eCFR text of 14 CFR 91.411 and 91.413 to read what it means on the job.
Open at “91.411 test” AC ElectricityAC Principles
Turn the loop of a 3D generator and watch the meter swing, then meet Michael Faraday, who discovered induction in 1831.
Open at “Generator” Solid-State and Digital ElectronicsBasic Logic Gates
A 3D micro switch on a landing gear: set the gear down and locked, try it out of rig, and read the gear-down signal.
Open at “Downlock” Flight InstrumentsGyro Instruments
Push the rim of a spinning 3D rotor and see the motion appear 90 degrees later in the direction of spin: precession.
Open at “Precession” DC ElectricitySeries Circuits
The picture-option question that started the rule, a path traced on an FAA figure, and a dim landing light to solve.
Open at “One path” Aircraft WiringHarness Fabrication
The Harness Bench: build twelve cable ends from the drawing with real crimp tool data, ring out the harness and find a planted fault.
Open at “Harness Bench”The Course Around the Lessons
The Course Library
Every lesson in a plain list of topic courses, one per room.
Open the course library Front doorThe Training Hangar
A 3D building students walk through: classrooms with lecturing instructors, desks that open the lessons, lab benches and a library.
Walk the hangar SimulatorThe Avionics Circuit Lab
The circuit simulator and avionics bench behind the labs. Every meter reading comes from a real circuit solver, not a script.
Open the Circuit LabIf a page is slow to open the first time, the preview server is starting. Give it a minute.
Read the Library
Everything on this site is written up in full in the pedagogy library on GitHub: the learning science behind each move, how each part should look and teach, and how a lesson is built, step by step.
Principles
66 chapters in seven groups, from learning science to assessment and motivation. Each gives the evidence, the effect size and when not to use it.
Open on GitHub craft/interactionsInteractions
31 interaction patterns: what the student does, when it teaches, when it does not, and how the course builds it. Plus the mixing guide.
Open on GitHub craft/media-motionMedia and Motion
Figures, animation, simulations, 3D and short video: when each one teaches and how to build it for a phone.
Open on GitHub craft/history-incidentsHistory and Incidents
How to tell a person’s story or a real accident from the official report, and how to check an image’s licence.
Open on GitHub craft/visual-designVisual Design
Electric Ink, the one look every lesson uses: tokens, type, the accent per room, cards, documents and the phone rules.
Open on GitHub buildBuild
The method and the tools: the pipeline, the paged lesson format, the sims, the hangar, testing and publishing.
Open on GitHub skillsSkills
The written instructions AI agents load to build, so a rule set in one review reaches every later build.
Open on GitHub showcaseThis Site
The source of this showcase: plain HTML, CSS and JavaScript with no build step, and the snapshot of the course’s shared parts.
Open on GitHubCredits and Licence
The CAET course and this library are the work of Nick Brown, Aircraft Electronics Association, and his course team.
Text
The text of this site is licensed under Creative Commons Attribution 4.0 (CC BY 4.0). Share and adapt it with credit.
Code
The code, including the snapshot of the course’s shared lesson parts in assets/core/, is licensed under the MIT licence.
FAA figures and federal text
FAA handbook and advisory circular figures, the FAA handbook text and the eCFR text of 14 CFR 91.411 are US government works in the public domain. Each is credited where it appears.
Other images
Every other image is credited where it appears. The drawings and icons in the demos were drawn for the course.
- FAA-H-8083-30B, Aviation Maintenance Technician Handbook, General, Figure 12-82.
- FAA-H-8083-31B, Aviation Maintenance Technician Handbook, Airframe, Figures 11-161 and 11-162.
- FAA Advisory Circular 43.13-2B, Acceptable Methods, Techniques, and Practices: Aircraft Alterations, Figure 3-1 and the quoted paragraphs.
- FAA-H-8083-25B, Pilot’s Handbook of Aeronautical Knowledge, Chapter 8, quoted text.
- 14 CFR 91.411, from the eCFR (www.ecfr.gov), up to date as of 29 September 2026.
- Typefaces: Space Grotesk, IBM Plex Sans, IBM Plex Mono and Newsreader, under the SIL Open Font License, served by Google Fonts.