Fleet Health
Fleet Health at https://rotorlab.app/fleet/health is condition monitoring across your fleet, computed from filed flight logs. RotorLab trends peak vibration, battery sag under load, and motor output balance for every monitored airframe. Readings that exceed a limit are flagged, and so are readings trending steadily upward while still within limits, which is the early signature of a failing bearing or a degrading pack.
Health trending is a paid add-on billed per aircraft. Switch monitoring on per aircraft in the Fleet Manager; the card at the top of this page shows how many monitoring slots are in use.
Where the numbers come from#
Ground stations can attach the flight log when they file a flight, and RotorLab retains the file with its flight record. A monitored aircraft's logs are read automatically and the measurements land on the flight; the health page then computes everything on read from those per-flight metrics. There is no stored score to drift out of date.
Only measured flights feed health. A hand-logged flight is a real flight and counts toward hours and currency, but it measured nothing, so it is left out of trends rather than diluting them with silence.
A trend needs at least 3 measured flights. With fewer, the page says "Not enough history to judge trends" and shows only the readings themselves. A trend compares the newest third of the flights against the oldest third; the page does not dress a handful of noisy points up as a regression.
The overview#
The page opens on the whole monitored fleet: how many airframes are being watched of those registered, how many alerts and warnings stand against them, how many are measured and clear, how many are monitored with no log filed yet, and how many measured flights are behind the trends.
An aircraft nobody is monitoring is listed on the board below but never counted as clear. Nothing is reading it, and a summary that called it fine would be reporting a clean bill of health for something unread.
What is flagged gathers every alert and warning across the fleet into one list, worst first, each with what was measured and the dates it came from. Each name opens that aircraft.
Against the rest of the fleet ranks every monitored airframe on peak vibration, battery sag and motor output spread, with the fleet average drawn as a line through the bars. A trend says whether an aircraft is getting worse than it was; this says which one is worse than its siblings, which catches a machine that has been the outlier since the day it was built and which a trend on it alone can never show. The average is the average of the airframes shown, so it never includes an aircraft the page is not drawing. One monitored aircraft is not ranked: an average made only of itself is a true comparison and a useless one.
The ranking is deliberately measured against your own fleet rather than a published limit. A limit answers "is this airframe unsafe", which the flags above already do.
The fleet board#
One card per aircraft, with a colored edge for its worst finding (red alert, amber warning, green clear). Each card shows the aircraft's name and registration, its worst flag or "Nothing flagged", total flights and hours, when the last flight was filed, and its alert and warning counts. An aircraft without monitoring says so on its card. Click a card to open the detail panel.
Reading an aircraft's detail#
The detail panel shows stat boxes (flights filed, hours flown, flights analyzed, model, serial, status), then the findings. Every flag says how many flights it was derived from and the dates they were flown, so you can go and look. The flags the page raises:
| Flag | Meaning |
|---|---|
| Severe vibration | Peak vibration reached 60 m/s2 or more. Check prop balance, motor bearings, and anything loose before the next flight. |
| Vibration above the usual limit | Peak vibration reached 30 m/s2, the usual investigate line. |
| Vibration is climbing | Peak vibration is up 25% or more across the last flights. |
| Large battery sag | The pack sagged 1.5 V or more under load: a tired pack or a poor power connection. |
| Sag is growing flight to flight | Sag grew by 0.3 V or more across the history, which is what an aging pack looks like. |
| One motor is working much harder | Average motor outputs differ by 120 us or more: a damaged prop, a failing bearing, or a frame that is not true. |
| Uneven motor outputs | Outputs differ by 60 us or more. |
| Motor outputs are diverging | The spread grew by 25 us or more across the last flights. |
| Pack internal resistance is high | Fitted internal resistance reached 30 milliohms per cell or more. |
| Internal resistance is climbing | Resistance rose 40% or more across the history. Unlike sag this does not depend on how hard the flight was, so a rise is the pack aging. Plan a replacement. |
| The estimator rejected measurements | An EKF innovation test ratio passed 1.0, which is what precedes most position failures. |
| Compass field tracks throttle | Field magnitude moved with throttle (correlation 0.55 or stronger): current-induced interference. Move the compass away from the power leads or fit an external one. |
| Accelerometer clipped in flight | Clipped samples are lost, not noisy; almost always a mounting or balance problem. |
| Last flight ended in a crash | The analyzer found a crash signature in the most recent filed log. |
When nothing is out of limits the panel says so explicitly, across how many flights it checked.
Against the rest of the fleet#
A trend says whether this aircraft is getting worse. The peer comparison says whether it is worse than its siblings, which catches an airframe that has always been the outlier and which a trend on it alone can never show.
The comparison uses aircraft of the same model when the fleet has enough of them, and says so; otherwise it compares against the whole fleet. It needs at least 3 registered aircraft and at least 2 measured flights on each side, and when it cannot be drawn it says why. The compared measures are peak vibration, motor output spread, accelerometer clipping, worst EKF innovation, and minimum satellites, shown as this aircraft against the fleet average with the percentage difference.
Trends#
Charts plot peak vibration, battery sag, motor output spread, and flight duration across the filed flights, oldest to newest.
Filed flights and stored logs#
The Filed flights table lists each flight with its stored log file, source format, duration, and the three headline measurements (vibration, sag, motor spread) plus a verdict (clean, or the crash reason).
The file cell is live:
- The filename is a download link, with the file size. Download is never gated; it is your own file.
- A state chip shows where an unread log is: queued (waiting for the analyzer), reading (being read now), failed (the analyzer could not read it), or too big (stored, but above the size read automatically).
- Read appears on a log that has not been read and is not already on its way, and reads it now. Reading a stored log is the paid act: it needs Fleet Health on the aircraft or the Crash Analyzer on the account. The log stays stored either way, so you can analyze flights recorded before monitoring was enabled, with no re-upload.
- Delete removes the stored file. The flight record and any measurements already taken from it stay.
The Stored logs card below the table shows how many files you hold, your usage against the storage allowance (and where the allowance comes from), and the retention window. Set Keep logs for N days (1 to 3650) and press Save; shortening the window sweeps logs past it immediately and tells you how many went. Storage itself costs nothing and needs no add-on.
Acting on a degrading trend#
A rising trend is the point of the page: it is the warning before the failure. When an airframe is flagged, open a work order for it in Maintenance and set the aircraft to In maintenance in the Fleet Manager so the availability picture on the dashboard stays honest. The flag's flight list tells you exactly which flights to look at, and each is one click from its stored log.