For pilots
ACARS for X-Plane 11 and 12 explained
An ACARS client is a program your virtual airline has you run alongside X-Plane 11 or 12. It reads the sim through datarefs, the named values X-Plane exposes for everything in the simulation, then records the flight and files it with your airline. A client that uses X-Plane's built-in network interface needs no plugin inside X-Plane.
Jordan HavardFounder, Skyvex SoftwareIf you fly X-Plane with a virtual airline (VA), your ACARS client reads the sim through datarefs. X-Plane exposes these out of the box, so on a standard install there's very little to configure. In our experience, when something does go wrong it's almost always a port or a firewall.
How an ACARS client reads X-Plane
A dataref is a named value inside X-Plane that holds one piece of the simulation's state. There are thousands of them. A few that matter for ACARS:
| Dataref (example) | What it holds |
|---|---|
sim/flightmodel/position/latitude | Your latitude |
sim/flightmodel/position/longitude | Your longitude |
sim/flightmodel/position/elevation | Your altitude above sea level |
sim/flightmodel/position/groundspeed | Your ground speed |
sim/flightmodel/position/vh_ind_fpm | Your vertical speed |
X-Plane listens for network messages on a UDP port (49000 by default). An ACARS client running on your computer sends X-Plane a request saying "send me these datarefs, this many times a second". X-Plane then streams the values back until the client stops asking. Nothing is installed into X-Plane for this, because the network interface is built in.
From those values the client works out your position, your phase of flight, your takeoff and landing times, your fuel burn and your landing rate.
Landing rate in X-Plane
X-Plane doesn't keep a single "vertical speed at touchdown" value the way some other simulators do. ACARS clients therefore calculate the landing rate themselves from the data in the last moments before the wheels touch. That's one reason two different clients can show slightly different landing rates for the same landing. What is a good landing rate covers what the numbers mean.
X-Plane 11 vs X-Plane 12
Both versions use the same dataref system and the same network interface, so one client can support both the same way. A few dataref names and aircraft behaviours changed in X-Plane 12, so check your airline's client lists the version you fly.
Do you need XPUIPC or a plugin?
Some older ACARS software reads X-Plane through an extra add-on that translates X-Plane data into a format originally built for other simulators. Clients that read datarefs directly don't need it. If your airline's client says it connects to X-Plane natively, skip any extra installs.
What you need set up
- X-Plane 11 or 12 on Windows, macOS or Linux. X-Plane runs natively on all three, so a client that does too can run on the same machine.
- Your airline's ACARS client on the same computer, or on another computer on your home network.
- A VA account and a booked flight, so the client knows your route and aircraft.
- Default network settings. On a standard install there's nothing to change in X-Plane.
Start X-Plane, load your aircraft at the departure gate, open the client and check it shows a connection before you start tracking.
Running the client on another computer
X-Plane accepts connections from other computers on your network by default. To use a client on a second machine, enter the X-Plane computer's IP address and port (49000 unless you changed it) in the client. Both machines must be on the same local network, and the X-Plane machine's firewall has to let the traffic in.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Connects but shows no data | Another plugin is using port 49000 | Set a different port in X-Plane's network settings and match it in the client |
| Never connects | Firewall blocking X-Plane | Allow X-Plane through your firewall on private networks |
| Never connects to a remote PC | Wrong IP address, or Wi-Fi client isolation | Check the IP, and turn off client or AP isolation on your router |
| Odd fuel or engine values | Add-on aircraft with custom systems | Check your airline's approved aircraft list |
| Landing not recorded | Tracking stopped, or the sim was paused at touchdown | Keep the client tracking until you're parked |
| Phases look wrong after a reload | Aircraft moved while tracking | Return to where tracking stopped before resuming |
Custom datarefs in add-on aircraft
Some add-on aircraft model their systems with their own custom datarefs, alongside X-Plane's standard ones. An ACARS client reads the standard set, so if an aircraft keeps its real fuel or engine state only in custom datarefs, the client may see something different from what's on your cockpit display. Your airline's staff may already know which aircraft report cleanly.
Pausing and time acceleration
When X-Plane is paused, the values stop changing, and a good client notices and holds the flight. Time acceleration speeds the data up, which some airlines don't allow, so check your VA's rules before using it.
Tips for clean X-Plane flights
- Load at a gate or ramp start, not on the runway, so taxi and takeoff are recorded.
- Start tracking before you move.
- Don't reposition the aircraft with the map once tracking is running.
- Keep the sim running and unpaused through touchdown and rollout.
- Shut the engines down at the gate and let the client register that you've arrived.
Flying Microsoft Flight Simulator (MSFS) instead? See ACARS for MSFS. For how your position ends up on your airline's map, see flight sim flight tracking.
Frequently asked questions
Does ACARS work with X-Plane 12?
Yes. X-Plane 12 keeps the dataref system and network interface from X-Plane 11, so clients that support X-Plane 12 connect the same way.
Can I use ACARS with X-Plane on a Mac?
Yes, if your airline's client runs on macOS. X-Plane is native on Mac, so both can run on the same machine with no extra setup.
What port does X-Plane use for ACARS?
UDP port 49000 by default. If you change it in X-Plane's network settings, enter the same port in your ACARS client.
Do I need to turn on data output in X-Plane?
Not if your client requests datarefs directly: it doesn't need X-Plane's data output screen. If your client's guide says otherwise, follow it.
Does ACARS work with X-Plane on Linux?
It can. X-Plane runs natively on Linux, so any ACARS client with a Linux build can run on the same machine. If your airline's client is Windows or Mac only, run it on another computer on your network and point it at the Linux machine's IP address.
Where Stratos fits
Stratos reads X-Plane 11 and 12 through datarefs directly, with no XPUIPC or X-Plane plugin to install, and works with X-Plane's default network settings. It runs on Windows, macOS and Linux, and if you've changed X-Plane's UDP port you set the same one in Stratos under Settings, Simulator. The remote simulator setup guide covers running Stratos on a different computer from X-Plane.
Stratos by Skyvex Software
Free ACARS for every pilot.
On Windows, macOS and Linux.
Stratos reads Microsoft Flight Simulator and X-Plane directly. Continuous telemetry, a landing score from the raw data, and the PIREP filed before you leave the cockpit.