11 July 2024

The Civil Aviation Authority of Thailand (CAAT) has explained that 5G emissions do not affect aviation and confirmed that the signals are on a different wavelength. The CAAT also pointed out that they have been monitoring the issue closely since last year.

The CAAT’s clarification issued today (Thursday) came after airlines in the US issued warnings about the activation of 5G signals, in the C-Band band used by US telecom operators, because it may affect the safety of aircraft, especially while landing, causing concern globally.

The potential impact of 5G signals on aircraft relates to interference with the operation of critical and highly sensitive systems, especially the radio altimeter, which typically operates in the 4.2GHz – 4.4GHz range. The radio altimeter provides the height above ground to the flight deck systems. Any electromagnetic interference can cause inaccurate altitude information to be reported, which would be dangerous, especially when landing.

Interference with aircraft systems found in the United States has not yet been reported in other countries, because the 3.7GHz – 3.98GHz frequencies to be used for 5G services by US telecom operators are close to those used by radio altimeters devices, which may cause interference.

In other countries, such as France, Australia, and Japan, this problem has not been encountered because they ensure that network bands and aviation frequencies are 100 or 200MHz apart. Additionally, 5G base stations must protect against the transmission of signals in the aviation frequency bands and they must be located at least 200 meters from aircraft approach and departure paths.

In Thailand, 5G uses the 2.6GHz frequency band, which is quite a distance from the radio altimeter frequency band, and should not cause interference.

Moreover, the CAAT has been notifying airlines since June 2021, after receiving information and notifications from the US FAA and International Civil Aviation Organisation (ICAO).

To date, there have been no reports of interference with flight operating systems by 5G signals in Thailand, but it remains an issue which the CAAT will monitor closely.