Reference

29Internet connection

The complete picture of what needs a connection, what works offline, what degrades, and how to prepare for a flight with no coverage.

Mixed, see chapter

The short answer#

The dividing line is simple, and it is worth internalizing because it holds almost everywhere in the app.

Flying works offline
Recording, navigation, task flying, airspace and obstacle warnings, the vario, the flight computer, the logbook and replay all run on the phone.
Sharing needs internet
Anything that involves other people or the server: live tracking, uploads, competitions, buddies, public tasks, XC leagues.
Data needs preparing
Maps, airspace, obstacles, tasks and waypoints are downloaded once and then work offline forever.

Good to know

You are never signed out by a lost connection. The app tells the difference between the server rejecting your session and the server being unreachable, so a whole day in a valley with no coverage leaves you signed in.

Feature by feature#

This is the full picture. Offline means it works with no connection at all. Prepared means download it once, then it works offline. Degraded means it works but with limits. Online means it needs a connection at the moment you use it.

Feature Needs Detail
Recording a flight Offline No account check, no server, no signal. The track goes straight to the phone.
Flight statistics Offline Computed on the device from your track.
Task navigation Offline Optimized route, start gates, turnpoints and goal all run locally.
Vario and sound Offline Phone sensors or a Bluetooth vario.
Thermal assistant Offline Derived from your own climb data.
XC Guide Offline All geometry is computed on the phone.
Airspace and obstacle warnings Prepared Install the files once. Warnings then run entirely offline.
The base map Prepared Download an offline region. Outside it, with no signal, the map is empty.
Terrain height, AGL, arrival, side view Prepared Inside a downloaded region it works offline. Outside one it needs a connection.
Thermal maps Prepared Included in a downloaded region for the seasons you downloaded.
Local tasks and waypoint lists Offline Anything stored on the device.
Task QR import and export Offline Two phones side by side need nothing else.
Layout sharing by QR Offline Same as tasks.
Logbook, flight detail, replay Offline Local database. The map underneath follows the map rules above.
IGC import and export Offline Local files.
Pilot identification QR Degraded Cached on the phone. Offline it shows the cached code with its cache date.
Live tracking Degraded Positions are buffered while offline and flushed when the signal returns. The buffer is in memory and capped.
Buddies overlay Online Positions are fetched live and are not cached.
Level messages and pilot status Online Sent to the organizer over the internet.
Post flight retrieve request Online Needs a signal to reach the organizers.
Weather stations Degraded The last loaded readings stay on screen. Nothing new arrives offline.
Sign in, register, password reset Online The one time you truly need a connection.
Profile and gliders Online Loading and saving both talk to the server. Gliders already added work offline.
Glider catalog search Online The catalog lives on the server.
Competitions, news, files, operations Online Pull anything you need before you leave coverage.
My tasks and public tasks Online Save them locally to fly them.
XC routes, challenges, leagues, records, feed Online Routes already saved to the device work offline.
Flight upload Online There is no upload queue. Upload when you have a signal.
XContest publishing Online Follows the upload.
Share image with a map background Online This map loads its style from the server, unlike every other map in the app.
Cloud layout templates and settings backup Online Local layouts and settings are unaffected.
Downloading maps, airspace or obstacles Online By definition.

Live tracking in poor coverage#

Live tracking deserves its own note, because it is the feature most likely to be misunderstood.

  • Your recorded track is never affected. Live tracking failing has no effect on your flight, your statistics or your IGC file.
  • Positions that could not be sent are held and flushed automatically when the connection returns, so a gap fills in afterwards.
  • The backlog is held in memory and is capped. A very long stretch with no coverage loses the oldest positions.
  • Force closing the app while offline loses the backlog entirely.

Caution

Tell anyone relying on your live track that the last visible point is where you last had signal, not necessarily where you are now.

Preparing for a flight with no coverage#

Everything on this list is done at home on Wi-Fi and takes about ten minutes. Afterwards the app is fully functional with the phone in airplane mode.

  1. Download an offline map region covering where you will fly and where you might land out. Use standard detail over the flying area.
  2. Install the airspace dataset for the country, and check it is enabled.
  3. Install the obstacle package for the area, and check it is enabled.
  4. Save any tasks you will fly to the device, and import the waypoint lists you need.
  5. For a competition, work through the Files tab and pull the airspace, obstacle and waypoint files the organizer published.
  6. Open the task once with a connection so the terrain heights for its turnpoints are resolved.
  7. Check your glider is set up, since the glide numbers depend on it.
  8. Charge the phone, and decide whether battery save mode is worth turning on.

Tip

The step people skip is opening the task with a connection. Without it, the ground heights at your turnpoints may be unresolved, and arrival height at goal is exactly the number you do not want to be missing.

Note

For travel abroad, also turn off Use mobile data for maps in Maps. With a downloaded region the map costs you nothing and never stalls waiting for tiles.

Keeping data usage down#

Download regions on Wi-Fi
A standard detail region over mountains can approach 1.5 GB.
Turn off mobile data for maps
Streamed tiles are the largest ongoing cost.
Live tracking is small but constant
Positions are tiny individually, but they are sent throughout the flight.
Buddies polls regularly
Turn the overlay off when you are not using it.
Upload flights on Wi-Fi
An IGC file with photos is the single largest transfer the app makes.