Altimeter #

This interface allows configuration of all barometric altimeter parameters.

Altitude Mode #

[QNH]
[QFE]

With this setting, the altimeter can be set either to QNH or QFE mode.

QNH is the altimeter setting that makes the altimeter read airfield elevation above mean sea level (MSL) when the aircraft is on the ground. In flight, it shows altitude (AMSL) and is used for standard navigation.

QFE is the setting that makes the altimeter read zero on the runway threshold. In flight, it shows height above the airfield (useful for circuit work but not for en-route navigation).

If the standard pressure of 1013.25 hPa is set (QNE), the altimeter is useful to keep flight levels (FL). This setting is normally used above the transition altitude for standardized vertical separation.

Auto Transition #

[Disable]
[Enable]

With this setting, the altimeter can be automatically switched to the QNH standard pressure of 1013.25 hPa once the aircraft passes the defined transition altitude or also called transition layer.

Transition Altitude #

50.00 FL

With this setting, the country-specific transition altitude can be defined as a flight level (FL). This parameter is only relevant when the automatic transition function (Enable) is activated. Below the transition altitude, the altimeter operates using the local QNH setting; above it, the system automatically switches to QNE based on the standard pressure setting of 1013.25 hPa.

Typical transition altitudes vary by country and region. In parts of Central Europe, values as low as 3,000 ft (FL30) are common, while in the United States the standard transition altitude is generally 18,000 ft (FL180). Each country or airspace authority defines its own applicable transition altitude.

Alt. Source #

[TE Sensor]
[Baro Sensor]
[GPS/FLARM]

Either the TE sensor or the baro sensor or even an external source like GPS or FLARM can be selected as the altitude source. The baro sensor is the default. Using the TE sensor is only meaningful if total energy altitude is required or for specific test scenarios.

Alt. Quantization #

[Disable]
2
5
10
20

This setting defines the quantization interval of the altitude display between 2 and 20 meters (or 6–60 ft). In the image above, the default interval is 10 meters. The last two digits of the altitude then scroll upward or downward like a mechanical counter wheel, which greatly improves readability during altitude changes compared to a standard digital readout.