Tutorial: what the Fleet is for

Five minutes with Fleet on ten flights made for it, with a known answer.

One flight log answers what happened in this flight. The Fleet answers the questions a single log cannot: is it getting worse (a motor wearing out, a battery losing capacity), which flight was the first to cross a limit, and which logs have a finding - across every log in a folder, with the same automatic checks as the Log panel. It keeps an index on this computer; the logs stay where they are.

The example

examples/fleet: two quad-copters, X8-A and X8-B, ten ArduPilot flights between 2 Sep and 17 Oct 2026 (the date of each flight comes from its GPS time).

1. Index it

1. Fleet in the top row (beside Recordings and Sweeps) ▸ Try the example fleet (or Add a folder… and choose examples/fleet). The ten logs are read once; Update later reads only new and changed files.
2. It opens with the number Vibration · max above 30 (the limit the health check uses): the trend of every flight, the limit as a dashed line, and the list - one flight, X8-A_2026-10-07 (67 m/s/s, with clipping).

2. Follow one copter

1. Type X8-A in the search: the trend is that copter alone - 18, 19, 22, 25, 29, then 67. The vibration grew for five weeks before the bad flight: a bearing wearing out, visible long before it failed. Type X8-B: flat, about 17.
2. Click the last point (or the flight in the list): its findings - Vibration, Clipping, Log warnings - each with Open here, which opens the log at that moment with the Log panel.

3. Search by finding

1. Clear the number (No number) and the search, and choose the level Warning or error: three flights - X8-A's last one, X8-B's flight of 19 Sep (5 satellites, HDOP 3.2 - a stretch of poor GPS) and of 17 Oct (the battery sagged under its low-voltage limit - a worn pack).
2. Any finding ▾ narrows to one kind (only the GPS ones, only the battery ones).

With your own logs

Add a folder… takes a folder of .bin / .tlog / .ulg logs, sub-folders too, and keeps watching it: Update after a day of flying. A log without GPS time gets the file's date (marked *). The numbers you can follow are the health checks' (vibration, clipping, GPS satellites and HDOP, battery voltage, EKF, motor balance, Vcc...) and the flight's length.

The answer

The logs were made by tools/make_fleet_example.py from the same flight: X8-A's vibration scaled 1.0 → 1.78 over five flights and a loose propeller in the sixth; X8-B with a stretch of five satellites (118-152 s) in one flight and an 880 mAh battery in another.