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Summary
DGCA has asked all airlines to modify radio altimeters, a cockpit tool to measure altitude of an aircraft, so that they are tolerant to 3,300-3,670MHz C-band of 5G services by 31 December 2027.
Ever found your mobile phone's signal to be patchy while waiting for a flight? That’s because telecom operators can’t provide stronger signals near airports, as these can interfere with a small cockpit tool—a radio altimeter.
The electronic gauge, which measures the altitude of an airborne plane, feeds data to multiple automated systems on board. A wrong reading can be a safety risk, especially during poor visibility. But the restrictions have sparked concerns as telecom operators expand 5G coverage and prepare for even stronger 6G networks.
Now, the civil aviation regulator has asked all airlines to modify the altimeters so that they are tolerant to 3,300-3,670MHz C-band—a key range of spectrum to provide 5G services, according to the Director General of Civil Aviation (DGCA) order dated 19 November 2025. Mint has reviewed a copy of the order.
The required modification or retrofitting must be completed by 31 December 2027, the order said.
India is not alone in facing this challenge. Countries such as the US and those in Europe have faced similar challenges, with regulators proposing deadlines extending to 2029–2032 for full fleet retrofits. But that has also caused a spike in demand. According to estimates by the American regulator Federal Aviation Administration (FAA), upgrades will cost around $4.5 billion for the US fleet alone.
To be sure, the US had earlier addressed 5G interference concerns by requiring upgrades to aircraft radio altimeters, setting a February 2024 deadline. It later said the entire airline fleet had completed these upgrades by September 2023, mitigating immediate risks. However, the country now has plans to expand 5G into a higher spectrum band.
Since the 2022 rollout of 5G in India, telecom operators have had to limit signal strength near airports and follow strict exclusion zones to avoid interference with aircraft systems. According to the November order, the DGCA has also prohibited pilots from conducting automatic landings and from using enhanced flight vision systems for touchdown in aircraft with radio altimeters that are not tolerant of 5G airwaves.
“There are airplanes with an old generation of altimeters, which can cause interference with 5G currently and 6G in the upper C-band in future such as 4.4-4.8GHz,” said Bharat Bhatia, president of ITU-APT Foundation of India, which works with industry and government on telecom policy. “The altimeter replacement is the only solution, which could take time owing to a similar demand from other developing countries.”
According to Bhatia, current rules restrict 5G operations within 2.1 km of the runway ends and within 910 metres of the runway centreline—zones that cover terminal areas at most Indian airports. It effectively limits 5G deployment within airport premises, he said.
The extended band, such as 3.7-4.2GHz, which is allowed to support 5G services in other countries, is restricted in India, he said.
In response to Mint's emailed queries, Boeing said, “We’ll defer to the airline operators for any comments". Honeywell Aerospace, a key manufacturer of radio altimeters used in planes, said, “We are currently in direct engagement with the concerned authorities, including civil aviation ministry and DGCA and are responding to the query.”
Queries emailed to the department of telecommunications (DoT), the civil aviation ministry, IndiGo, Akasa, Spicejet, the Cellular Operators Association of India (COAI) on the matter did not elicit any response until press time.
“Regarding the 5G rollout, as part of a wider industry coalition, we continue to work with the FAA and other involved agencies to study the issue further and work toward solutions,” Airbus said in a statement.
An Air India official said that work on retrofit or upgrade of altimeters started “long time back”. “The airline will be fully compliant before the said deadline,” the official said. “Some of the narrow-body Airbus aircraft we have are already updated and work is ongoing in some,” the official said, without giving a breakup.
Operators rely on in-building networks
To be sure, telecom operators are also relying on in-building solutions inside airports and 4G spectrum bands such as 2,100MHz and 2,300MHz for mobile services.
There are concerns regarding 5G/6G services, but 6G is expected only by 2030, said a government official, speaking on the condition of anonymity. “The expectation is that the altimeters can be modified before that.”
There is a global demand for replacing such altimeters, which is delaying the replacement process in India, said an executive with an aircraft maker. Airline operators have been working with aircraft and equipment manufacturers to fix altimeters for the past couple of years, the executive said.
According to FlightGlobal, a London-based aerospace publisher, airlines in the US say they can speed up altimeter upgrades for 5G but want compensation for the costs involved.
About the Authors
Jatin Grover
Jatin is based in New Delhi and writes on telecom and technology with a keen interest in policy and regulation. With over five years of reporting experience across Informist Media, Financial Express and now Mint, he has extensively covered the telecom, information technology, electronics and semiconductor sectors.<br><br>A commerce graduate, Jatin's work focuses on tracking industry developments, regulatory changes and policy decisions that shape India’s evolving digital ecosystem. Over the years, he has reported on key trends and shifts across these sectors, bringing clarity to complex policy and business issues.<br><br>Known for his strong news sense, Jatin focuses on breaking stories and delivering in-depth reporting that offers readers an understanding of complex topics, policy decisions and corporate developments. His work often examines the intersection of policy and business, highlighting how regulatory decisions impact industry strategy, pricing, and consumer outcomes.<br><br>He brings a strong domain understanding for Mint and his work is widely picked up by other media firms. With a focus on accuracy and depth, he aims to break down developments into clear, accessible insights for readers, while continuing to track emerging trends shaping the future of India’s telecom and technology sectors.
Abhishek Law
Abhishek Law has spent 18 years in journalism, which in news industry terms means he has survived several newsroom restructurings, countless “urgent” press releases, and more cups of tea than he can reasonably count. Based in New Delhi, he covers aviation for Mint, a sector where aircraft, oil prices, geopolitics and airline CEOs regularly conspire to make his life interesting.<br><br>Most of his time gets occupied by translating airline jargon like ASKs, yields, load factors and fleet strategies into language that doesn’t require a pilot’s licence. His motto is simple: if readers need a glossary, he hasn’t done his job properly.<br><br>On most days, the quadragenarian is tracking airline strategies, policy changes and the occasional mid-air disruption that suddenly become a stock market story. When planes are behaving themselves (which is not very often nowadays), he strays into other corporate beats like steel, trying to figure out what’s really happening.<br><br>He loves to talk, especially ask—that one more question which people are uncomfortable with, and saving contacts in his phone as a "Source who may or may not pick up calls”. <br><br>But, on a serious note, the goal remains simple: cut through jargon, find that additional detail, and turn complicated business stories into something one can actually enjoy reading.
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