EFIS Data Manager

Ground-support automation for GRT HXr / Mini EFIS systems on macOS. It keeps a GRT chart USB drive current, archives the flight data your EFIS records, and provides an analysis dashboard for engine and flight data.

Why

Seattle Avionics does not offer a Mac version of its Chart Data Manager — the official tool is Windows-only. If you fly behind a GRT EFIS and use a Mac, there is no supported way to keep your chart/nav data current or to work with the flight data your EFIS logs. This project fills that gap: plug in your EFIS USB drive and everything happens automatically, with a companion dashboard for analyzing what your engine and airframe are doing.

Independent project, not affiliated with or endorsed by GRT Avionics or Seattle Avionics. Use at your own risk; always verify chart currency before flight.

New here? See GETTING-STARTED.md for a five-minute quick start. This README is the full user guide.

Functionality

Menu-bar tool (automatic, runs in the background):

• Detects when an EFIS-managed USB drive is inserted (recognized by a durable identity file the app writes, not by its volume name). A never-before-seen drive is adopted once via Prepare Drive.
• Downloads and stages current chart data and GRT navigation databases to a local USB image. You choose which chart products to pull based on your subscription — VFR sectionals, IFR low, IFR high, approach plates — so a VFR-only pilot isn't downloading (or paying storage for) IFR data.
• Syncs the drive to the current data (delta sync; resilient to interruptions).
• Prepare Drive: formats and provisions a fresh USB stick as an EFIS drive.
• Archives the data your EFIS writes each flight: FDL engine/flight logs, DEMO recordings, snapshots, settings backups, and the logbook.
• Notifications, a "Recent Errors" view, and a Diagnostics panel.

Analysis dashboard (opens in your browser):

• Operations list — every engine start/stop cycle, flagged flight vs. ground.
• Flight detail — stacked, reorderable panels (EGT, CHT, power, flight data, and more) with full 1-second resolution, synchronized zoom/pan, a shared crosshair, and any parameter selectable into any panel.
• GAMI lean test — auto-detects lean sweeps and shows the classic EGT-vs-fuel-flow plot with per-cylinder peaks, GAMI spread, and peak order.
• Trends — rolling engine-parameter trends across flights.
• Alerts — CHT/EGT/oil exceedances and anomalies, with jump-to-timestamp.
• Oil consumption — tracked from logbook additions and manual oil-change entries, with a consumption-rate chart.
• CSV export for flight summaries, trends, oil, and raw FDL data.

Prerequisites

• A Mac running macOS (Apple Silicon or Intel).
• A Seattle Avionics chart subscription (for chart/nav downloads).
• A GRT EFIS USB drive (or a blank USB stick to prepare one).
• An internet connection for the first install.

You do not need to install Python or anything else yourself — the installer sets up everything it needs.

Install (recommended, no technical steps)

1. Go to the latest release and download EFISDataManager.zip (under "Assets").
2. In your Downloads folder, double-click the ZIP to unzip it. You'll get a folder named EFISDataManager.
3. Open that folder and right-click install.command → Open. (Right-click → Open is needed the first time because the app isn't from the App Store — see First launch security note below. A normal double-click may be blocked by macOS.)
4. A Terminal window opens and the installer runs. Follow the on-screen prompts:
   • On a new Mac, macOS may ask to install Command Line Tools — click Install and accept.
   • You may be asked for your Mac password (to install Homebrew/Python).
   • The installer then downloads everything and sets up the app. The one-time browser download is ~100 MB, so give it a few minutes.
5. When it says "All done," the EFIS Data Manager icon appears in your menu bar (top-right) and in your Applications folder.

That's it. The installer handles Homebrew, Python, the app dependencies, the menu-bar app, and starting it at login — all using your home folder, nothing hardcoded.

First launch security note

Because this is a free, un-notarized app (not distributed through the App Store), macOS Gatekeeper will warn you the first time. This is expected:

• For install.command: right-click it → Open, then click Open in the dialog. You only need to do this once.

• On macOS Sequoia (15) and later, right-click → Open no longer offers an override for scripts. Instead, after the first blocked attempt, go to System Settings → Privacy & Security, scroll to the message naming install.command, and click Open Anyway. Then run it again.

• If it still won't open, clear the download quarantine flag in Terminal and run it once more:

  xattr -d com.apple.quarantine ~/Downloads/EFISDataManager/install.command

Install with git (for developers)

If you're comfortable with the terminal and have git:

git clone --branch v1.0.1 --depth 1 https://github.com/flightlead404/EFISDataManager.git
cd EFISDataManager
./install.sh

To update later:

git fetch --tags
git checkout v1.0.1   # whichever release you're moving to
./install.sh

First-time setup

1. Launch EFIS Data Manager from /Applications (or it starts at next login). Look for the small attitude-indicator (PFD) icon in the menu bar, top-right.
2. Settings… — set your aircraft tail number, choose your Archive and USB Image folders, and select which chart products to download (VFR sectionals, IFR low, IFR high, approach plates) to match your subscription.
3. Seattle Avionics Login… — enter your subscription email and password. Credentials are stored in the macOS Keychain (see Security below), never in the project or in a plaintext config file.
4. Analysis Dashboard… — opens the browser dashboard. In its Settings, set your number of cylinders and engine parameter thresholds.

How to use

Once set up, the tool lives in your menu bar and works mostly on its own.

Everyday use — just plug in your drive. When you insert your EFIS USB drive, the tool automatically archives the flight data your EFIS wrote (FDL logs, DEMO recordings, snapshots, settings, logbook), imports it for analysis, and brings the drive's charts and nav data current. Chart/nav update checks also run on a background schedule, so the local copy stays fresh between insertions.

How a drive is recognized — by identity, not by name. The tool treats a mounted volume as EFIS-managed if and only if it carries the app's identity file (EFIS_DRIVE_ID.json) at its root. The volume label plays no role in detection — the old EFIS/EFIS_1/EFIS_SPARE name matching is gone. Labels are now purely cosmetic (a Finder convenience).

First contact with any drive is always an explicit user action: a never-before-seen drive — even one that already holds a GRTCHARTS/ folder or a full chart payload — triggers no automatic archive or sync. The app just notes it found an unmanaged drive and points you at Prepare Drive to adopt it. Nothing happens to a drive until you've prepared or adopted it once.

Preparing or adopting a drive (Prepare Drive…). Use the menu bar's Prepare Drive… item. The first step, Select Drive to Prepare, lists your removable volumes (internal and Time Machine drives are excluded) and asks you to type the exact name of the one to use — this only chooses the drive; you set its label in a later step. The app then inspects the drive and offers the right path:

• Blank / no chart data → Start clean: reformat as FAT32 with an MBR partition map (the layout GRT EFIS expects), write a fresh identity, and populate it with your current chart and nav data. You're asked for a cosmetic EFIS_<name> label and a final confirmation before anything is erased.
• Previously-used GRT drive (has chart data from the Windows Chart Data Manager or an older version of this app, but no identity yet) → choose Adopt & update or Start clean. Adopt & update is non-destructive: it keeps your existing charts, writes the identity file so the drive becomes managed, and runs an incremental sync that brings only the delta current — no ~9 GB re-copy, no reformat.
• Already managed (has our identity) → Update (non-destructive incremental sync) or Start clean (reformat).

Flight-data safety. Before either Start clean or Adopt, if the drive holds un-archived flight data or logbooks (FDL logs, DEMO recordings, snapshots, settings backups, or a logbook export), you're prompted to Import first (archive it, preserving the data) or Erase (skip archiving). This applies to both paths — Start clean erases everything, and Adopt can overwrite settings backups — so flight data is never silently lost.

Cosmetic labels. During Start clean the Choose Label step lets you name the drive EFIS_<your text> (letters/numbers, upper-cased, 11-character FAT32 limit; blank → EFIS). It is pre-filled with the drive's current label suffix, so re-using the same name is one click, and if you type a value that already starts with EFIS_ it is not doubled. The label is only for telling rotating drives apart in Finder; the app keys on the identity file, never the label. A distinct label per drive is still recommended for clarity.

Start clean is destructive. It erases the whole target disk. Double-check the volume name before confirming, and never point it at a drive holding data you want to keep. Adopt & update is non-destructive.

Migration note. Because detection is now identity-only, any drive that was previously auto-detected by its EFIS… label must be adopted once via Prepare Drive → Adopt & update (non-destructive) before automatic archive/sync resumes for it.

Using multiple EFIS drives. If you rotate more than one drive — say the one in the airplane, an n-1 spare, and one at the Mac — the tool tracks each drive independently by a durable identity file (EFIS_DRIVE_ID.json, written at the drive's root). This means an in-progress or interrupted sync on one drive is never confused with another, even when macOS reassigns mount paths (the same stick can come up as /Volumes/EFIS one time and /Volumes/EFIS_1 the next).

• Recommended: give each drive a unique, meaningful cosmetic label via Prepare Drive (EFIS_SPARE, EFIS_N1, EFIS_2, ...). It plays no role in detection — that's the identity file — but it keeps the drives clear in Finder and in the app.
• Every managed EFIS drive you plug in is archived and refreshed to current — including the n-1 emergency drive when you bring it back. There are no per-drive roles; no drive is skipped.
• Known limitation: connecting two EFIS drives at the same time is not supported. Connect them one at a time. The identity keying prevents state from being mixed up, but concurrent drives are neither guaranteed nor tested.
• The identity file is small, visible, and safe to leave on the drive — the HXr ignores it. If you ever wipe a drive's contents, it's re-created on the next sync.

Other menu items: Settings…, Seattle Avionics Login…, Analysis Dashboard…, Diagnostics… (versions, paths, and a self-check), plus a Recent Errors view. Quitting from the menu is logged.

Notes & limitations

• EFIS software updates (HXr / Mini display firmware) are detect-and-notify only. grtavionics.com is behind bot protection that blocks automated downloads; the tool tells you when a new version is available so you can download it manually. Nav database updates are fully automated.
• The chart data files, credentials, and analysis database stay local to your Mac. Nothing is uploaded anywhere.
• First chart sync to a slow USB stick can take a while (many thousands of small files). Subsequent syncs are incremental and much faster, since only changed files are rewritten.
• Hidden ._* companion files on the drive. When macOS writes a file to a FAT32/exFAT drive it also creates a small hidden AppleDouble companion (._<name>) to hold metadata the drive can't store natively. On a full first-time populate this roughly doubles the number of files written, which is the main reason the initial sync is slow; it is unavoidable on macOS (the underlying com.apple.provenance attribute cannot be removed) and harmless to the EFIS, which ignores these files. Routine incremental updates only rewrite changed files, so they create very few.

Security & privacy

• Your Seattle Avionics credentials are stored in the macOS Keychain, using the system security service — the same protected store macOS uses for Safari and Wi-Fi passwords. They are never written to the project directory, the config file, or any log, so there's nothing sensitive to accidentally commit or share.
• Everything stays on your Mac: chart files, the analysis database, and your flight data are all local. The tool talks only to Seattle Avionics and GRT to fetch updates; it uploads nothing.

Uninstall

launchctl unload ~/Library/LaunchAgents/com.efisdatamanager.plist
rm ~/Library/LaunchAgents/com.efisdatamanager.plist
rm -rf "/Applications/EFIS Data Manager.app"
# Optional: remove the project folder, ~/EFIS data, and app-support config

Support

This is an early release for testing. Please report issues with the contents of ~/EFIS/DataManagerLogs/efis_data_manager.log and the Diagnostics panel output.

License

Copyright (C) 2026 Martin C. Walker.

EFIS Data Manager is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See the LICENSE file for the full text.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

The AGPL is a strong copyleft license: anyone who distributes this software or a modified version — including running a modified version as a network service — must make the complete corresponding source code available under the same terms. The source is at https://github.com/flightlead404/EFISDataManager.