A spokeswoman for the French agency Agence France-Presse has said (translated) that the use of a 5G device on the flight risks disrupting devices that are designed to measure altitude. They say that these devices play an extremely important role during landing.
The DGAC has also recommended that if there is a case of obstructing the equipment of any aircraft, the flight crew should immediately inform the Air Traffic Controllers (ATC) to alert the authorities at the airport. The DGAC has also stated that it has placed certain conditions for the placement of 5G base stations at the airport, so that there is no risk of flights landing.
Not only this, the signal strength emanating from 5G base stations placed near the main airports of France has also been banned. In addition, 5G base stations continue to be monitored around all French airports in collaboration with the agency responsible for radio frequencies.