Van's Builder Assistant

For builders of Van's kit planes. Free, for Mac and Windows.

Track the build. Ask the manual.

The construction manuals with a checklist inside, notes where you need them, and answers that cite the page.

NOTE:Only the RV-12iS is supported at the moment. Support for other Van's models will be added based on interest, so say which one you are building.

Version 0.1.5, released 09/24/2026. All versions and release notes are on the releases page.

The app showing page 12iS/U-03 of the empennage fairings section: the manual page in the middle with Figure 1 outlined, the list of pages on the left, and the six steps of the page on the right.
Section 12iS/U, page 03. The page as Van's drew it in the middle, its steps listed beside it.

Import the manuals

Point it at the construction manual PDFs you downloaded from Van's, one file per section. Each page is read into its steps, figures and notes, so the section appears in the list with a progress bar the moment it is parsed.

When Van's publishes a new revision, import it over the old one. Your progress and notes carry across.

The manuals are not included. Van's provides them to kit owners.

The Manuals pane with sections 06 to 11 listed, each with a progress bar, and the status bar reading Parsing 7/7 12iS-U_12iS.pdf, page 2/12.

Track the steps

Mark a step done, in progress or skipped, from the list or by clicking it on the drawing. The date is kept, and the time it took if you want to log it.

Notes attach to a step, a figure or a whole page, and show up right under the text they belong to.

The step list for page 12iS/U-03: steps 1 to 3 marked Done with dates and minutes, a note under step 2, and step 4 In progress.

Ask about a step or a drawing

Select a step or a figure and ask. The AI assistant searches the manuals for related steps, reads the drawings, and looks through builder sites such as VAF, the Van's site, EAA and Kitplanes. Answers cite their sources, and a citation jumps back to the exact step.

Like any AI, it can be confidently wrong. Treat an answer as a pointer, and check it against the manual page it cites and your own judgement before you drill, cut or rivet.

This part is optional and runs on your own Anthropic API key, entered in Settings. Without a key, everything else works.

The Ask pane: a question about getting the fairing flush with the skin in step 4, and an answer that cites 12iS/U-03 Step 4 and Step 1.

Search everything

Press ⌘K on a Mac or Ctrl+K on Windows from anywhere in the app. One search box covers the manuals, your notes and your past conversations, and a hit opens the page or the thread it came from.

⌘F (Ctrl+F) finds text within the open section, including on pages Van's shipped as pure drawings.

The search palette with the query smooth transition: two hits in the manuals and one in a conversation.

What stays on your computer

The manuals, your progress and your notes live in a folder on your machine. Nothing is uploaded and there is no account. The only thing that leaves your computer is a question you choose to ask, which goes to Anthropic with the page it concerns.

Free for any Van's builder. Questions, bugs and requests for other models: use the contact details below.