January 24, 2022 - 11:22 am

The Concern Over 5G And Flight Safety

    Travel plans for thousands of passengers, including those travelling to India, have been disrupted after several international airlines, including Air India cancelled some flights to and from the US over the issue of deployment of new 5G service. The airlines have warned that the signals from new 5G phone service could interfere with airplane navigation systems. 5G airwaves pose a risk to aircraft instruments, impacting at least some commonly used jets like the Boeing 777, which will need to undergo retrofitting to avoid the issue.

Last February, the two biggest telecom operators in the US -- AT&T and Verizon -- spent a whopping $76 billion to buy mid-range spectrum so they can start offering 5G services. The operators were gearing up to launch the service in December. But this date was first pushed back to January 5th and later again to January 19th. This delay was due to concerns that the new set of radio frequencies they purchased, called the C-Band, could interfere with a critical plane instrument that helps pilots land a plane. A day before the new technology was set to go live, airlines in the US warned of a catastrophic aviation crisis that could render a number of wide-body aircraft unusable and strand thousands of Americans overseas. The panic came to a head when international airlines like Air India, Emirates and Japan Airlines cancelled flights to some American cities that were scheduled to arrive on January 19th, citing uncertainties because of the 5G rollout.

The US aviation regulator warned of a potential interference with aircraft’s radar altimeters. For all airborne vehicles — an aircraft, spacecraft, or even a missile—an altimeter is crucial to gauge the altitude and the distance covered. Altimeters are of three main kinds: barometric, laser, and radio or radar altimeters. Most commercial passenger and cargo aircraft use a combination of all these altimeters along with global positioning system (GPS) to determine their path, as well as fact or such as height above sea level, presence of high rises, mountains, and other obstacles, and the likely flying time. The radio or radar altimeter is a very small, low-power radar system that operates in the 4.2-4.4 GHz frequency microwave C-band. The high frequency of these altimeters enable aircraft makers to install small antennae that produce powerful signals that can be relayed quickly and accurately. The US regulator feared that the instruments may give wrong readings if its radio waves don’t bounce back from the ground because of 5G interference. The concern is that 5G frequencies come too close to spectrum band use by altimeters.

In India, where 5G is yet to be rolled out, the frequency range for5G telecoms operations is pegged around 3.3-3.68 GHz. It is learnt that the Federation of Indian Pilots has, in its meetings with the Department of Telecommunications (DoT), expressed concern about the frequencies being close together. The DoT however, assured them that there would be no interference as the frequencies for commercial 5G services were at least 530MHz away from those used by altimeters.

Flights to the United States from India resumed on Thursday as the Federal Aviation Administration (FAA) cleared the landing of more aircraft even in low visibility conditions, despite the roll out of C-band 5G technology. Following the announcement, Air India resumed flights from India to the US, with the first flight for John F Kennedy International Airport in New York departing in the morning.