Open source aircraft projects
This site exists partly because the same problem kept recurring across several projects: aviation data that everyone needs is either locked in a vendor format or trapped in a PDF. Everything below is open source, and everything below either produces or consumes the formats this site defines.
Open Checklists
This site. A machine-readable checklist corpus with real provenance, an editor, a preflight log and an open pilot logbook format. Schemas are permissively licensed so anyone can implement them, including in closed commercial products.
Junco
An open flight computer for experimental and ultralight aircraft: an ESP32 sensor hub, your phone as the display, and a black box on an SD card. It consumes the checklist format defined here, which is why that format has stable phase identifiers — so software can map a checklist to a moment in flight.
Nuthatch
An open single-seat ultralight aircraft design. The reason Part 103 is a first-class citizen here rather than an afterthought: an aircraft that needs no approved flight manual has no source document to transcribe, so its checklist has to be authored — and the format has to say so honestly.
Flight simulator
An open source simulator, in progress. It will load checklists from this corpus directly, which means practising a procedure in the sim and flying it in the aircraft use the same file.
Aircraft profiles
A profile describes how one airframe is wired — limits, sensor maps, calibration baselines, unit preferences — so Junco supports a new aircraft without a firmware change. Profiles are TOML rather than JSON, and that difference is deliberate.
A checklist is a document with a source you can cite and a verification state that has to travel with it. A profile is hand-edited hardware configuration: there is no upstream document to transcribe and no provenance to record, and someone will edit it in a text editor at a hangar with cold hands. TOML is the better shape for that, so the two formats are not forced to become one.
| ParaPlane PM-2 Twin-engine two-stroke powered parachute |
pm2.toml · draft |
The format specification is spec/aircraft-profile.md. Junco's own copy redirects to it, so there is one authoritative definition rather than two that drift apart.
Why the formats matter more than the site
A checklist that only this website can read would be worth very little. The point of publishing schemas — and of making them permissive enough for closed products to adopt — is that the corpus becomes usable by panel software, by simulators, by logbook apps and by whatever comes next. The site is one consumer of the data, not the owner of it.
That is also why the corpus lives in a git repository rather than a database: if this site disappears, the data and its history survive, and anyone can host it.
Contributing to any of it
Checklist contributions go through the contribute page. For the other projects, the repositories are the place to start. The most useful thing anyone can do here is not code: it is taking one checklist and checking it against its source document, because that is the one thing the tooling cannot do for itself.