Pradeep S. Mehta and Sidharth Narayan | 5G rollout and aviation safety: Need solutions over long term

The recent fiasco concerning 5G telecom services and civil aviation safety and security in the United States has been resolved for the time being, after some patchwork measures. Flights from other countries have now resumed, and other aviation authorities have confirmed that the issue was specific to the United States. The Telecom Regulatory Authority of India (Trai) has clarified that this problem does not exist in India and even though we are yet to roll out the 5G networks, the problem would not arise.

The problem arose in the United States as the spectrum for operation of 5G services and aircraft operations were extremely close. Mobile phone firms in the US had rolled out 5G services, operating in the 3.7-3.98 GHz range on the spectrum, known as the C-band. It had the potential to interfere with the proper working of crucial instruments on aircraft, such as altimeters, which operate in the 4.2-4.4 GHz range.

In other countries like India, Japan, South Korea and members of the European Union bloc, among others, the 5G spectrum was chosen in the 3.3-3.8 GHz range, which is quite distant from the spectrum used by most aircraft.
Altimeters measure how far above the ground an aircraft is travelling, and are also used to facilitate automated aircraft landings. They also help in detecting dangerous wind currents. Any interference in such instruments could compromise the safe landing of aircraft, especially during poor weather conditions.

Notably, altimeters possibly being impacted by the C-band are reported to be prevalent in many popular aircraft models, such as the Boeing 777, 787, 737, among others. These models are used by major American and international airlines, like United Airlines, Emirates Airways, Air India, Nippon Airways, Japan Airlines, among others. This led to many of these airlines temporarily cancelling/rescheduling flights to affected airports of the United States.
However, after some delay, the US Federal Aviation Administration (FAA) has cleared an estimated 78 per cent of aircraft (including these models) for operating in airports where the 5G C-band is deployed. More are expected to be cleared soon. Despite these clearances, however, the aircraft manufacturers have warned pilots of possible adverse impact on crucial aircraft components due to 5G interference.

Notably, this comes even after mobile network companies in the United States have agreed to temporarily defer turning on a few wireless towers located near key airports. They have also agreed to create buffer zones around 50 airports in the US for six months to reduce interference risks. This however remains patchwork, as future consumer demand for 5G in and around airports could compel its deployment.

Better coordination between the FAA with the Federal Communications Commission (FCC) in America at the time of the spectrum auction, as well as with the counterparts of the FAAs the and FCC in other countries at the time of 5G C-band rollout, could have avoided such a situation. Multilateral standard setting organisations such as the International Telecom Union and International Civil Aviation Organisation could also be made use of.

Further, attention also needs to be given to the possible impact of 5G on military aircraft. While the FAA has begun approving civilian aircraft for use around 5G towers, military flight authorities are yet to release any additional guidance for military pilots, given that the 5G testing programme run by the US Air Force is yet to announce its results.

The EU Aviation Safety Agency had claimed that the issue of aviation interference was specific to US airspace, and no risks were identified in Europe. A similar statement has now also been given by TRAI and the Cellular Operators Association of India (COAI) with respect to India.

This came after the Federation of Indian Pilots (FIP), with a strength of 6,000 pilots, had expressed aviation safety concerns over the possible interference of 5G wireless signals with aircraft equipment.

In India, 5G is set to offer various benefits to consumers and businesses alike. The country has currently earmarked 3.3-3.6 GHz range for 5G, and many Indian telecom operators are using lower bands at the moment for offering 4G.

However, it must be noted that some mobile manufacturers are bringing out products capable of supporting 5G up to 4.2 GHz. This may cause similar problems in India, should India decide to raise the 5G spectrum band to the US standard of 3.7-3.98 GHz range, in future. This becomes more important, as India intends to start the rollout of 5G later this year.

It is imperative for the Directorate General of Civil Aviation (DGCA) to work closely with TRAI and DoT to ensure that long-term solutions are implemented in India for 5G and aviation safety to coexist. Also, as demanded by the Air Line Pilots’ Association (ALPA), a detailed evidence-based study needs to be carried out to ascertain the 5G interference and aviation safety issue, especially for Indian flights landing in the US. The absence of such a study was acknowledged by minister of state for communications Devusinh Chauhan in the Lok Sabha recently.

A “whole of government” approach, as well as inclusive stakeholder consultations, will need to be adopted for the safe and timely rollout of 5G in India, so that such aviation safety concerns and chaos are avoided. Lessons also need to be learnt for harmonising other vulnerable sectors with further developments in telecommunication technology such as 6G. Adopting scientific regulation-making tools at the time of the spectrum auction, through tools such as the Regulatory Impact Assessment (RIA), would also be helpful in this regard.