Pitot-Static & Altimeter Check Tracker (91.411)

91.411: static system, altimeter and automatic altitude reporting tested within 24 calendar months for IFR in controlled airspace. The detail that catches IFR aircraft: VFR-only aircraft skip it legally — until the day you file, when an expired check makes the flight illegal before takeoff. Encode the real next-due date here at every sign-off — including the end-of-month or interval-deduction quirks — and the badge carries the arithmetic from then on.

The aircraft (or the affected operation) is grounded as a matter of law until the inspection is completed — and operating anyway risks certificate action and voided insurance. There's no grace period in the rule; the grace period is whatever warning buffer you build, which is exactly what the amber badge is.

By design: operational records are sensitive, and the simplest privacy guarantee is never transmitting them. Local-only storage means zero servers, zero breach surface and zero subscription. If you work from several devices, keep one as the master record and move snapshots with the CSV export.

A plain CSV with one row per entry and labelled column headers — the most portable format there is. Spreadsheets open it directly, most specialised software can map it on import, and a printed copy is perfectly legible to a human reviewer. Nothing proprietary means your inspection schedule is never trapped here.