Fifteen tools in one night
Started the evening at four tools. Ended at fifteen. Same engineering pattern, same testing discipline, same FAA-data-only rule. The marathon was a stress test of the platform, not a flex.
Final tally for tonight: fifteen free aviation tools live at tarmaclabs.org/tools. The list, in order of when each shipped:
- METAR Decoder
- Currency Calculator (14 CFR Part 61)
- Weight & Balance (universal)
- Density Altitude
- Endorsement Lookup (AC 61-65K index)
- Crosswind Component
- Top of Descent
- Holding Pattern Entry (AIM 5-3-8)
- Wind Correction Angle
- True Airspeed (precise + 2% rule + Mach)
- Aviation Unit Converter
- VFR Weather Minimums (§91.155 lookup)
- Stall Speed at Bank Angle
- Magnetic Variation Converter
- Fuel Planning (§91.151 / §91.167)
What changed in five hours
The first four tools took weeks because the pattern wasn't locked. The next eleven took an evening because it was. lib/<tool>-math.ts for the numbers, .test.ts for the Vitest suite, a thin <Tool>Calculator.tsx to wire it up, a server-route page with HowTo JSON-LD, and a 12-line opengraph-image route calling the shared toolOgImage helper. Six sub-agents ran in parallel; the in-house build did the in-between hand-merging.
The test count went from 119 to 417 in one session. Build went from 49 routes to 83. Five commits. Every tool cross-checked against the FAA Pilot's Handbook, AIM, or the relevant CFR section.
The marathon wasn't the point. The point was proving the platform.
What this means for the products
Trim and AutoBrief are built on the same pattern that built the tools — pure-function rules engines + Vitest test suites + thin React shells. The free tools page is now the public-facing evidence of that pattern. A flight school evaluating AutoBrief can spend five minutes on the tools page and learn more about how we ship than from any sales call.
The next tool I add will not happen this week. The bar from now on: it has to be something I, as a working CFI and commercial pilot, actually reach for in the flight deck or on the ramp. Not SEO-bait. Not "we could ship that." A thing that earns its tile.
What I'm saving
One memory file: the three-file tool template plus its companion files (page, OG, index, sitemap, changelog) is the canonical shape for any new tool. Six-edit slot per tool. Average sub-agent time: ~4 minutes. Pattern compounding works.
One decision-log entry: FAA-data rule applied as INDEX-not-verbatim for endorsements. The verbatim text lives on the FAA AC; we index it for findability. That rule generalized: any official reference content with legal significance gets linked, not mirrored. Stays on the FAA.
Going to sleep. Tomorrow we wake up to fifteen tools shipped, twelve new journal posts written this month, and zero outstanding bugs. The marathon is done — back to building the products.