While technology enthusiasts are eagerly waiting for 5G connectivity, it seems airlines are unhappy with it. The US Federal Aviation Administration (FAA) recently warned that 5G networks may interfere with in-flight instruments like altimeters– which basically measure the height of the aeroplane from the ground. Soon after this warning, major airlines like British Airways, Emirates, Japan Airlines, Lufthansa, All Nippon Airways and Air India decided to cancel some flights to the US.
Note that not all flights to the US are getting cancelled. Only those locations like Los Angeles, Chicago, San Francisco and other major locations which have got 5G networks up and running are seeing a disruption.
Basically, some airlines are scared that the 5G networks may indeed interfere with the in-flight altimeter and may lead to a flight crash. Or, simply why even take the risk when FAA itself is warning about it. Having said that, what readers should understand is that there are many other airlines like Virgin Atlantic, Air France-KLM and others who have not cancelled any flights to the US.
AIR INDIA RESUMES 6 INDIA-US FLIGHTS ON BOEING B777 AIRCRAFT
Despite the so-called 5G scare, Air India announced that it has resumed six India-US flights on Boeing B777 aircraft after Boeing itself gave the clearance to operate them, as per news agency PTI. This comes after Air India had cancelled eight flights on India-US routes due to deployment of 5G internet in North America.
WHY ARE AIRLINES SCARED OF 5G ROLLOUT IN THE US
It all boils down to frequency. The frequency range with which altimeters operate is 4.2-4.4 GHz. The problem is the 5G frequencies are close to this range and may cause interference. As per a report by Reuters, altimeter readouts are also used to facilitate automated landings and to help detect dangerous currents called wind shear. United Airlines CEO Scott Kirby said last month the FAA’s 5G directives would bar the use of radio altimeters at about 40 of the biggest US airports.
“The Federal Communications Commission (FCC) has recently taken action to reallocate a portion of the 3.7–4.2 GHz frequency band, making the frequency spectrum from 3.7–3.98 GHz available for flexible use including 5G applications. This spectrum will be auctioned to new licensees beginning in December 2020. The aviation industry noted in the FCC rulemaking process that deployment of 5G networks in this frequency band may introduce harmful radio frequency (RF) interference to radar altimeters currently operating in the globally-allocated 4.2–4.4 GHz aeronautical band. Radar altimeters are deployed on tens of thousands of civil aircraft in the United States and worldwide,” as per Radio Technical Commission for Aeronautics , a non-profit organisation.
Talking about interference, the RTCA said, “Radar altimeters used in civil and commercial aviation operate using either unmodulated pulse radar or frequency-modulated continuous wave (FMCW) radar technology, with FMCW being far more common among models developed in the last few decades. In either case, the above ground level (AGL) altitude of the aircraft is measured in the radar altimeter by transmitting radio frequency (RF) energy down to the ground and receiving a portion of this energy back through reflection off of the terrain or other obstacles, and determining the round-trip propagation time of the RF energy. The radiated power levels are low, typically on the order of one watt, and thus highly sensitive receivers are required for radar altimeters to function properly.”
“As such, radar altimeters are highly susceptible to RF interference entering the receiver, which can negatively impact their performance. Radar altimeters operate in an Aeronautical Radionavigation Service (ARNS) spectrum allocation in the 4.2–4.4 GHz band, which is internationally recognized and protected by the International Telecommunications Union (ITU). Radar altimeters may be susceptible to RF interference received either within this band of operation or within adjacent or nearby frequency bands,” it added.
WHAT AIRLINES ARE TRYING TO EXPLAIN WITH RESPECT TO 5G INTERFERENCE?
According to the FAA, “Radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations…limitations prohibiting certain operations requiring radio altimeter data when in the presence of 5G C-Band interference”. This is applicable for fixed-wing aircraft and helicopters.
WHAT DO THE TELECOMS COMPANIES SAY?
According to a report by Reuters, “Verizon and AT&T have argued that C band 5G has been deployed in about 40 other countries without aviation interference issues. They have agreed to buffer zones around 50 airports in the United States, similar to those used in France, for six months to reduce interference risks.”
WHY 5G INTERFERENCE IS ONLY AN ISSUE WITH US AIRSPACE
New agency Reuters in its report said that the European Union in 2019 set standards for mid-range 5G frequencies in a 3.4-3.8 GHz range, a lower frequency than the service set to be rolled out in the United States.
“The bandwidth has been auctioned in Europe and is in use in many of the bloc’s 27 member states so far without issue. The European Union Aviation Safety Agency (EASA), which oversees 31 states, said on December 17 the issue was specific to US airspace. At this stage, no risk of unsafe interference has been identified in Europe,” it said.