Atmo calibrates most of itself. This article lists what it learns on its own, the one reference it takes from you, what accuracy to expect, and a symptom table for the questions pilots ask after their first flights with it.
What Atmo calibrates by itself
| What | How Atmo handles it | When |
|---|---|---|
| Gyro drift | Estimated continuously as part of the solution | Throughout the flight, seeded while the glider stands still on the ground |
| Instrument tilt | Measured while the glider stands still for about three seconds; the attitude at that moment becomes the level reference | Once per switch-on, between power-up and the first GPS fix |
| Airspeed-system error | Learned separately for slow, medium and fast speeds, because an error fixed to the glider averages out over a full circle and what remains is the error itself | While thermalling |
| Air density | Measured from static pressure against GNSS altitude, so a sun-heated temperature probe does not distort true airspeed | During climbs and descents of a few hundred metres |
None of this needs a setting. The airspeed correction and the density in particular get better as the flight goes on: the first circles of the day are when Atmo is least certain.
The level reference — the one thing that comes from you
Atmo needs to know how the instrument sits relative to the glider's flight attitude, because the vertical wind depends on the exact angle at which the air meets the fuselage. One degree of error at 110 km/h is about half a metre per second of netto error.
It takes that reference each time the Era is switched on: whatever attitude the glider has while it stands still before the first GPS fix becomes "level". So switch the Era on with the glider standing still and leave it still for the first seconds — if it is being pushed around until the GPS finds its fix, the measurement is skipped. On the ground a glider rests on its main wheel and its tail or nose, which is rarely the attitude it flies at, so in most gliders the reference is off by a degree or a few.
What that does:
- The smart vario in straight flight carries a steady offset — this is where you see it.
- The smart vario in established circling comes from the total-energy vario and is not affected.
- The horizontal wind is hardly affected.
How to give Atmo a better reference: switch the Era on with the glider in flight attitude — wings level and the fuselage at the attitude the glider manual gives for levelling, usually with a trestle under the tail — and keep the glider still until the GPS has a fix. After that you can move the glider; the reference holds until the next switch-on. Do this at least for your first flights with Atmo, so that you know what your installation reads.
What accuracy to expect
- Wind in circles settles over the first circles and keeps improving as Atmo learns the airspeed error.
- Wind in straight flight stays live — that is what Atmo is for — but heading is hardest to observe in long, smooth glides. There the wind can drift by several knots, more in perfectly smooth air, until the next turn re-anchors it. The average wind smooths this; it does not correct it. For a final glide, plan with the more pessimistic of Atmo's wind and the classic wind.
- The smart vario is built to ignore horizontal gusts and pull-ups; stalls and hard pull-ups can still briefly produce a false reading. Its level in straight flight depends on the level reference above and on Atmo's built-in glider model — the polar and wing loading of a typical standard-class glider, not your Era's glider settings.
- Values are withheld rather than guessed: on the ground, in the first seconds after takeoff, and when the airspeed stops agreeing with the GNSS and the wind, the Wind page and the cyan needle go blank until Atmo's inputs make sense again.
Troubleshooting
| What you see | Usual cause | What to do |
|---|---|---|
Wind page reads No data before takeoff | Correct behaviour: there is no airflow to solve the wind triangle with | Nothing — it fills in a few seconds after takeoff |
Wind page stays No data in flight and there is no cyan needle | The licence is not active yet: loaded without the restart that follows, a file renamed on the way to the card, or firmware without Atmo | Switch the Era off and on; check that the file on the card is called exactly Fusion.lic and load it again; update the firmware |
| The licence is loaded but still nothing in flight | The licence was made for a different serial number, or the Era takes its position from a FLARM unit instead of its own GPS receiver | Compare Setup › Service › Device Info with the serial in your licence e-mail; check the Era's GPS antenna; then contact us |
| The smart vario shows steady lift or sink in calm straight flight | Level reference taken with the glider on its wheel and tail, and Atmo's built-in glider model differing from your glider | Switch on in flight attitude for a better reference; expect some offset in gliders far from a standard-class sailplane |
The SVAR navbox reads 0.0 | Atmo has no value yet, or the navbox is on a second-seat instrument | Use the cyan needle or the Wind page, which show no value instead of zero |
| The AHRS page shows a different attitude than before | With Atmo running, the AHRS page uses Atmo's attitude ahead of an LX AHRS module | Compare the two on the ground; contact us if they disagree clearly |
| The current wind direction wanders on a long glide | Heading is hardest to observe in smooth straight flight | Expected; the next turn re-anchors it. Plan final glides with the more pessimistic wind |
| The current wind moves around inside a thermal | Gusts in the thermal, and an airspeed error Atmo has not learned yet | Use the average; it settles over the first circles |
| Wind and vario blank for a while in flight, then come back | Atmo stopped trusting an input — typically a blocked or iced pitot, a GPS outage or a manoeuvre far outside normal flight | Nothing in the air; if the airspeed indication was also wrong, check the pitot-static system after landing |
| The cyan needle stays put for a few seconds after a pull-up | It holds its last trustworthy value through manoeuvres | Expected — it resumes when the glider is flying steadily again |
| The cyan needle disagrees with the classic needle in turbulence | By design: gusts move the airspeed, not the airmass | Nothing — this is the difference Atmo makes |
| The final glide uses a different wind than the Wind page | The final-glide calculation still uses the Era's classic wind | Compare the two — see flying with Atmo 3D |
| The sound behaves like the old vario | Smart vario sound is off, the instrument is in speed-command mode, or Atmo has no value yet and the sound has fallen back to the classic vario | Tick Setup › Vario/SC › Smart vario sound; check the vario/SC mode |
When to contact us
If Atmo still shows nothing in flight after the checks above, or the smart vario keeps a clear offset after you switched on in flight attitude, contact your dealer or LX support. Tell us the instrument's serial number and firmware version, the glider type, and what happened in flight: when Atmo stopped or started, and what the airspeed indication was doing at the time.