US airlines have started installing new radar altimeters that are immune to interference from 5G cell phones.
Earlier this year, aircraft manufacturers and airlines were most concerned about the introduction of the 5G wireless standard in the United States. Because it could not be ruled out that 5G radar altimeters (also called radio altimeters) and other aircraft systems would interfere. The US Federal Aviation Administration (FAA) imposed restrictions on certain types of aircraft and airports, while mobile phone providers At&T and Verizon have not yet been allowed to fully roll out their 5G services around airports.
Regional airlines in particular are still affected by the restrictions: At the behest of the FAA, they must install radio frequency filters in aircraft that have been identified as particularly sensitive to interference from 5G by the end of the year.
Retrofitting of the Airbus A320 in the USA has now begun, as the French technology group Thales confirmed on September 14. 50 aircraft have already been fitted with the improved ERT530R radio altimeter. There are around 2,000 orders for the system, which was approved by the European Aviation Safety Agency EASA in July. On September 1st, Thales also received certification for the ERT540R for the A330 and A340. Thales says it is the first company to offer 5G-resistant radar altimeters.
The ERT530R and ERT540R use a band pass filter that isolates signals within certain frequencies – in this case those between 4.2 and 4.4 GHz. Radar altimeters work in this C-band frequency range. Signals above or below, such as those of the 5G C-band between 3.7 and 3.98 GHz, are attenuated. According to Thales, the new radio altimeters can be installed with a simple unit swap.