Engine Data

Import your engine monitor's data logs to chart every flight: CHT and EGT by cylinder, time over your CHT limits, trends against the engine's own history, a health status on the Maintenance page, and a per-pilot view for owners and the maintenance officer.

Overview

Engine Data turns the logs your engine monitor already records into a picture you can use. Import the files from the monitor’s SD card and 5-by-5 splits them into flights, charts the cylinder head temperature (CHT) and exhaust gas temperature (EGT) of every cylinder, counts any time over your CHT limits, and watches for changes against the engine’s own history.

It lives on the web dashboard: Maintenance → Engine Data, or the Engine Data widget on the Maintenance page. Engine Data is part of the paid plans.

Which monitors work

Engine Data reads the CSV data logs Garmin displays write to their SD card. It was built and tested with the Garmin GI 275 set up as an engine display. Other Garmin displays that write the same log format, such as the G1000 and G3X, should import the same way; if a file from yours doesn’t, email it to support@fly5by5.com and we’ll take a look. JPI and other monitors aren’t supported yet.

What 5-by-5 can show depends on what your monitor records. An engine-display-only install (such as a GI 275 EIS) records engine data and a GPS track but not airspeed or attitude, so climb, cruise and descent are worked out from GPS altitude.

Who can do what

  • Everyone in the group can see the flight list, each flight’s detail, the trends and the Maintenance-page widget.
  • Owners, admins and the maintenance officer can import and delete logs, set the CHT limits, fix which flight-log entry a flight belongs to, and see the Pilots tab.

Importing Logs

  1. On the web dashboard, open Maintenance → Engine Data (or click Flights on the Engine Data widget).
  2. In Import logs, click Choose folder and pick the folder from the monitor’s SD card, or Choose files to pick individual .csv files.
  3. 5-by-5 checks each file and tells you how many are new and how many were already imported. Click Import.

Pick the whole card every time; there’s no need to sort out which files are new. Files already imported are skipped, and so are power-ups where the engine never started (the monitor writes a file every time it’s switched on). A short engine run on the ground is kept as a ground run, not a flight.

The first time you import, 5-by-5 links the monitor to the aircraft you’re viewing, so later imports go to the right airplane. If some files come from a different monitor, a warning says so before you click Import; import them only if that monitor is in this aircraft.

When a log holds more than one takeoff, for example a fuel stop with the engine left running, each leg becomes its own flight.

Matching flights to the flight log

The engine logs don’t record who flew, so 5-by-5 matches each flight to its flight-log entry. That’s how flights get a pilot. Matching runs after every import:

  • One flight-log entry that day: every flight that day belongs to it.
  • Several entries that day: the day’s flights are shared out by each entry’s tach time.
  • No entry that day (the outbound day of a trip logged once on the return day): the trip’s entry up to a week away, when it has tach time left to cover the flight.

If a flight lands on the wrong entry, or none, open the flight and change it under Flight log. Any entry within 10 days is listed. If a flight was never logged, log it on the Flights page and it will be matched automatically. When some flights aren’t matched, a Match to flight log button above the list runs the matching again.

The Flight List

The Flights tab lists every flight, newest first, 50 to a page: date, route, pilot, airborne time, cruise power and altitude, cruise fuel flow, peak CHT, cruise CHT spread (hottest minus coolest cylinder), and a flag for time over a limit.

  • Filter by period (all time, last 90 days, last 12 months, or a year), by limits (Above a limit or Reached the red line), by pilot, or by airport. Owners, admins and the maintenance officer can pick any pilot; everyone else can pick My flights.
  • Sort by clicking Date, Airborne, Peak CHT or CHT spread.
  • The tiles at the top describe the flights you’ve filtered to.

No reading in the fuel-flow column means the fuel-flow sensor read zero for the whole flight while the engine was at cruise power. One such flight is a glitch; several are worth having the sensor checked.

A Flight in Detail

Click any flight to open it:

  • Tiles: airborne time, fuel burned, cruise power and fuel flow, peak CHT (with cylinder and time), cruise CHT and EGT spread, and the fastest CHT cooling rate.
  • Limits on this flight: every stretch over the operating limit for more than a minute, and any time over the red line, with when it started, how long it lasted, how hot it got and which cylinder.
  • CHT and EGT by cylinder across the flight, with climb, cruise and descent shaded and your limits drawn in. Hover to read values.
  • Six smaller charts: GPS altitude, RPM, manifold pressure, fuel flow, oil temperature and oil pressure.
  • By cylinder: cruise and peak CHT and EGT for each cylinder.
  • Flight log: the entry this flight is matched to, which owners, admins and the maintenance officer can change.

Owners, admins and the maintenance officer can Delete this log. That removes every leg in the file; you can import the file again later.

Engine data also appears in the Flight Log on the Flights page: open a logged flight and the matched engine legs show below the route map and altitude profile, with peak CHT, cruise power, fuel flow, a small CHT trace and a link to the full view.

CHT Limits

Each aircraft has two CHT limits, set in the CHT limits box on the Flights tab:

  • Operating limit: the CHT you’d like to stay under. A flight counts against it only when a cylinder stays above it for more than a minute, so a brief climb peak doesn’t.
  • Red line: the engine’s maximum. Any time over it counts.

Leave a box empty to use the published value for your engine. For engine families where we’ve confirmed the figures (for example, Continental IO-520 and IO-550, and Lycoming O-360, IO-360, O-540 and IO-540), 5-by-5 fills in the red line from the engine’s type certificate data sheet, and the operating limit from the manufacturer’s recommended continuous CHT where one is published, or 400°F where it isn’t. Where the red line depends on the exact model (Continental O-470 and IO-470, Lycoming TIO-540), no red line is filled in: enter yours from the engine data sheet.

Changing a limit recalculates every imported flight. Published limits assume the probe type the manufacturer specifies (a bayonet or well-type probe); a spark-plug-gasket probe reads differently. Always check your own engine’s data sheet.

Red-line alerts

When an import includes a flight from the last 30 days where a cylinder went over the red line, the owners, admins, maintenance officer and any mechanic get an email and a notice in the Notification Center. One email covers every such flight in the import, listing each one with its peak, the cylinder and the time over the red line, and linking to the flight. Each flight is only ever alerted once, and older flights in a big history import don’t send email; they show on the Engine Data pages instead.

The Trends tab shows how the engine is doing over time:

  • A status at the top: Running in line with its history, Worth a look or Needs attention, with each finding and links to the flights behind it. Until there are about 20 flights at typical cruise power, it reads Still learning this engine.
  • Cruise CHT by cylinder over time.
  • Each cylinder’s CHT and EGT compared with the engine’s average. A cylinder that always runs hotter or cooler than the others is normal for that engine; this chart shows when one moves away from where it usually sits.
  • CHT spread, oil temperature, oil pressure and fuel flow in cruise.
  • Squawks, completed maintenance and oil samples marked on the same timeline; hover a point to see what happened nearby.

Only flights near the engine’s typical cruise power are compared, so a few flights at unusual power settings don’t look like a change. Each line is a rolling median of several flights, and a gap in a line means weeks with no flights.

The checks compare the latest 10 comparable flights with the 30 before them, and look for:

  • one cylinder’s CHT or EGT moving relative to the others, on most of the recent flights;
  • cruise CHT spread widening;
  • oil temperature or oil pressure in cruise changing;
  • any time over the red line in the last 30 days;
  • a sensor reading nothing: fuel flow at zero while cruising, or a CHT or EGT probe that’s dead.

The checks describe what changed. They don’t diagnose anything; your A&P decides what, if anything, to do.

On the Maintenance page

The Engine Data widget on the Maintenance page shows the same status with its top finding, the latest flight and its peak CHT, the number of flights in the last 90 days that reached the red line or stayed over the operating limit, and a small chart of cruise CHT by cylinder. Flights and Trends open the full pages.

Pilots

The Pilots tab, for owners, admins and the maintenance officer, shows how each pilot tends to run the engine. Pilots fly different routes and power settings, so each one is compared with what this engine normally does at the same cruise power, worked out from everyone’s flights:

  • typical cruise power and altitude;
  • fuel flow, CHT and EGT compared with that normal (fuel flow well above normal suggests a richer mixture, well below a leaner one);
  • typical peak CHT in climb;
  • the share of flights over the operating limit, next to the group’s share;
  • red-line flights, and the typical fastest CHT cooling rate.

Pilots need at least 8 matched flights before the comparisons show. It’s a starting point for a conversation, not a grade.

Asking AI About the Engine

Ask AI can read your engine data: the same health status and findings as the Trends tab, what the checks found over the past year, time over your limits, recent flights and monthly cruise CHT by cylinder. It also knows how recent the data is. Try:

  • “How is our engine running lately?”
  • “Has cylinder 3 changed since the last oil change?”
  • “Which flights went over the red line this year?”