US aviation hit by fears over 5G, Air India joins long list of cancellations

Air India said on Twitter that “due to deployment of the 5G communications in the US”, on Wednesday, it will not operate eight of its flights on the Delhi-New York, Delhi-Chicago, Delhi-San Francisco sectors. Besides Air India, American Airlines and Delta Airlines currently operate direct flights between India and the US.

The Director General of Civil Aviation (DGCA) is learnt to be coordinating with Indian carriers on the issue, which stems from a warning issued by the US Federal Aviation Administration (FAA) on January 14 that the new 5G technology being rolled out in the US from Wednesday could potentially lead to interference with on-board instruments such as radar altimeters.

Altimeters measure how far above the ground an airplane is flying. Radar altimeters operate in the 4.2-4.4 GHz (gigahertz) frequency range and the concern being flagged by aviation authorities and airlines is that the auctioned mid-range frequencies in the US are extremely close to this band. The US had auctioned 5G bandwidth to mobile phone companies in 2021 in the 3.7-3.98 GHz on the spectrum range called the C-band.

The use of C-band spectrum for deployment of 5G technology by telecom service providers has been a cause of concern for the aviation industry throughout the world. Across geographies, aviation regulatory bodies as well as airlines have argued that if the frequencies of commercial 5G deployment is “near” the frequency of the airwaves being used by wide-body airplane instruments such as the altimeter, it could disturb readings.

#FlyAI: Due to deployment of 5G communications in USA, our operations to USA from India stand curtailed/revised with change in aircraft type from 19th January 2022.

Update in this regard will be informed shortly.

— Air India (@airindiain) January 18, 2022

The issue is particularly of concern in the US, given the proximity of the two frequency bands. In most other countries and regions such as the European Union, where deployment of commercial 5G has started, most telecom service providers operate in the 3.4-3.8 GHz range. Similarly, in South Korea, 5G operates in the 3.42-3.7 GHz band. Both these frequencies are lower than the mid-band frequency of 3.7-3.98 GHz range in the US, which airlines say is extremely close to the 4.2-4.4 GHz range that the airlines’ altimeters use.

The issue appeared to particularly impact the Boeing 777, a wide-body aircraft used by carriers for long-haul operations.

Dubai-based Emirates announced that it would halt flights to Boston, Chicago, Dallas-Fort Worth, Houston, Miami, Newark, New Jersey, Orlando, Florida, San Francisco and Seattle. It said it would continue flights to Los Angeles, New York and Washington. In its announcement, Emirates cited the cancellation as necessary due to “operational concerns associated with the planned deployment of 5G mobile network services in the US at certain airports”.

Japan’s All Nippon Airways said in a statement that the FAA “has indicated that radio waves from the 5G wireless service may interfere with aircraft altimeters”. “Boeing has announced flight restrictions on all airlines operating the Boeing 777 aircraft, and we have cancelled or changed the aircraft for some flights to/from the US based on the announcement by Boeing,” ANA said. The carrier cancelled 20 flights to the US — to Chicago, Los Angeles and New York. AI also uses the 777s on the US routes.

The cancellations come even after US mobile phone carriers AT&T and Verizon, who are slated to launch 5G services, said they will postpone the launch of the service near some US airports.

Typically, in the telecom sector, the higher the spectrum frequency, the better the service. According to industry experts, the chances of interference of the two bands occur as telecom service operators, in order to extract the full value of 5G and therefore give their customers the best experience, push operations to the highest band possible. Similarly, altimeters of flights need to operate at higher frequencies in order to get the most accurate readings possible.

In India, too, where 5G rollout is yet to commence, the frequency range for 5G telecoms operations is pegged around 3.3-3.68 GHz. It is learnt that the Federation of Indian Pilots had in its meetings with the Department of Telecommunications (DoT) expressed concerns about the frequencies being close together. The DoT however, assured that there would be no interference as the frequencies for commercial 5G services were at least 530 MHz away from those used by altimeters, a government official said. The DoT stand has also been corroborated by the Cellular Operators Association of India (COAI), which said that commercial 5G and aviation could safely exist.

“We understand the concerns raised by Federation of Indian Pilots, and the matter has been highlighted in the past as well wherein the authorities have found the issue of spectrum interference uncorroborated. There is a gap of 530 MHz (from 3670 MHz to 4200 MHz) in the transmission of frequencies. Thus, making it safe for 5G and aviation to co-exist,” S P Kochhar, director general of COAI had said.