Since January 19, 2022, I have no idea what behavior the Radar Altimeters on board of the airplane I fly will show when flying in the USA. It could either fail, generate no data or even worse, create erroneous data which will be used by other aircraft systems. Pilots, just like myself, could be presented with the wrong flight altitude and unexpected behavior of other flight control systems. This all as a result of the rollout of 5G in the USA.
A lot has already been written and said about the issue. In the USA, the band used for 5G within the communication spectrum is between 3.7 – 3.98 Ghz. The buffer is 220 Mhz with the frequencies used in the aviation industry (4.2-4.4 Ghz). In Europe, this buffer is larger because 5G in Europe uses the band 3.3 - 3.8 Ghz. Nevertheless, EASA is still paying attention to the issue and participating in studies on the effect of 5G on aviation safety.
But in the US, due to the comparatively small buffer, combined with a much higher output power and different position of the 5G antenna, the risk of interference with aircraft systems is considered to be relatively high.
This interference may not impact the radio altimeters all in the same way, so the effects may be variable. Multiple systems on board can be influenced and start showing unexpected behavior. This includes crucial systems like the Autopilot, Autothrottle, Engines, Flight Controls, Flight Instruments and others. It is clear that this is an unacceptable risk to Flight Safety.
Furthermore, aviation receives yet another blow, in addition to the impact of the COVID pandemic. Since the rollout of 5G in the USA this week many restrictions apply at more than 100 airports in the US. As a precaution airlines from around the world are cancelling part of their flights and some aircraft types with the more vulnerable Radar Altimeters are banned from flying to the USA.
It seems that something went wrong in the governance and oversight of the communications spectrum policy in the USA
Against this background, it seems that something went wrong in the governance and oversight of the communications spectrum policy in the USA. How is it possible that the telecom giants pushing the 5G have ignored for so long the warnings given by the FAA and other aviation groups? Isn’t this another example of where financial benefits outweigh the importance the safety? Why has this not been solved before rolling out 5G networks? What role does the government have in this process and who will finally carry the responsibility if this leads to serious incidents?
Ultimately, the question is who will pay the bill for a very expensive conversion operation of existing radio altimeter systems in aircraft? In the meantime, until a technological solution is implemented, pilots must rely on the alternative methods of operation, hope no serious incidents will happen, and insist on a swift and solid solution to address 5G’s potential negative safety impacts.
by Otjan de Bruijn, ECA President, Captain Boeing 777