FAA Orders 58,500 Radio Altimeters Replaced by 2030

The FAA has ordered airlines across the United States to replace tens of thousands of radio altimeters. The instruments help pilots land safely when they cannot see the runway clearly. Airlines now have until the end of the decade to fit new equipment that can resist interference from 5G phone signals.

Find out why radio altimeters are so important for safe landings, and how airlines plan to pay for the change.

A radio altimeter tells a pilot exactly how high the aircraft is above the ground. Unlike a normal altimeter, which uses air pressure, it sends a radio signal down to the earth and measures how long the signal takes to bounce back. This makes it far more accurate close to the ground, which is why pilots depend on it during takeoff and landing, especially in fog, heavy rain, or at night.

The problem is that some radio altimeters can pick up signals from nearby mobile phone networks. In 2026, the Federal Communications Commission (FCC) approved a new part of the radio spectrum, called the Upper C-band, for 5G phone networks. This band sits close to the frequencies that radio altimeters use, so there is a small but real risk of interference.

To close that gap, the Federal Aviation Administration (FAA) signed a final rule on 24 July that requires affected aircraft to carry “interference-tolerant” radio altimeters, built to keep working even near strong 5G signals. The FAA says about 58,500 radio altimeters will need to be replaced or upgraded across the country.

Airlines flying scheduled passenger routes, along with large foreign carriers that fly into the US, have until 30 December 2030 to finish the work. Business jets and smaller general aviation aircraft have longer: their deadline is 31 October 2034. The FAA set two different deadlines because commercial airlines fly into busy airports more often, so their aircraft need the upgrade sooner.

The upgrade will not be cheap. Analysts think it will cost US airlines between $1.5 billion and $2.2 billion in total, since each new altimeter costs between $80,000 and $120,000. To help cover this, some of the money the FCC raises when it sells access to the new 5G spectrum, worth an estimated $3.8 billion to $5.7 billion, will go back to airlines as rebates.

The FAA and the FCC worked together on the plan. As well as the new rule for altimeters, the FCC has agreed to limit how much power 5G towers near airports can use, and how tall they can be. Both changes are designed to protect flights without holding back the rollout of faster mobile networks.

For passengers, the change should be almost invisible. Airlines are expected to carry out most of the upgrades during regular maintenance checks, so flights are unlikely to be delayed or cancelled because of the work. But the rule is a reminder that even small pieces of hardware, hidden under the nose of an aircraft, play a critical part in getting planes safely onto the ground.

Check your understanding

Key vocabulary:

• radio altimeter (noun) – an instrument that measures an aircraft’s exact height above the ground using a radio signal. Typical use: “requires … aircraft to carry ‘interference-tolerant’ radio altimeters”.
• spectrum (noun) – the full range of radio frequencies used for wireless communication. Typical use: “a new part of the radio spectrum, called the Upper C-band”.
• interference (noun) – unwanted signals that disrupt the normal working of electronic equipment. Typical use: “resist interference from 5G phone signals”.
• retrofit (verb/noun) – to fit new equipment onto an aircraft that is already built and in service. Typical use: “58,500 radio altimeters will need to be replaced or upgraded”.
• rebate (noun) – a partial refund, often paid back after money has already been spent. Typical use: “will go back to airlines as rebates”.

CEFR Level B1 / ICAO Level 4

Curious about an earlier chapter of this story? Read about the 2023 FAA deadline that first forced airlines to upgrade their altimeters.