Das SkyEcho funkt auch auf 1090 MHz rum, das darf man so ohne weiteres nicht überall.

Auch in UK darf man das nicht, wenn man per ModeS-Transponder sendet. Aus dem Handbuch:

Mode-S or ATCRBS

According to CAP1391 regulations, if the aircraft has an operating Mode-S transponder or ATCRBS beacon, the transmitter must be deactivated. Receive functionality may still be used. Deactivation of the transmitter is accomplished by removing device power or disabling the transmit capability via the configuration settings. These regulations are subject to change. Please be informed of the most current regulations at: https://www.caa.co.uk/General-aviation/Aircraft-ownership-and-maintenance/ElectronicConspicuity-devices/