It has been legal to use PLBs on land since January last year.

BBC: Reverse polarity a risk to climbers, mountain body warns

Magnets in avalanche transceivers, radios, personal locator beacons (PLBs) and cameras may also affect the map reading tool, she said.

BBC: Reverse polarity a risk to climbers, mountain body warns

Investigators of the February crash found that interference from PLBs carried by passengers had caused the "smart" long-range rescue beacons on the aircraft and life rafts to shut down.

BBC: Helicopter locator beacons return