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Summer Travel Alert: DOT Predicts Flight Delays Due to 5G Interference

All airlines have until July 1 to upgrade their altimeter technology ahead of the 5G network boost, but a significant number of aircraft have yet to be retrofitted

by Fergus Cole

June 26, 2023

Photo: KLM, Boeing 777-200ER. Courtesy of Alex Muromtsev / Unsplash

The U.S. Department of Transportation (DOT) cautioned travelers about possible flight delays this summer because some aircraft have not been retrofitted with updated altimeters before the July 1 deadline.

From July onwards, wireless network operators across the United States will increase their 5G signal strength in over 100 airports nationwide. This expansion of the 5G C-band signals could interfere with the radio altimeters of some aircraft, which are crucial in measuring an airplane’s altitude relative to the ground. Such interference could potentially cause dangerous situations for planes landing in low visibility conditions.

Photo: 5G Antenna. Courtesy of Baatcheet Films / Unsplash

Last year, network operators like Verizon and AT&T postponed their plans for higher-powered 5G networks close to airports due to concerns about potentially dangerous interference. The DOT then required all domestic and international airlines to upgrade their altimeter technology by July 1 this year, when the 5G frequencies will be increased, in order to address interference concerns.

Only planes with retrofitted altimeters will be permitted to land in low visibility conditions. Currently, more than 80% of aircraft in the U.S. have already had their altimeters upgraded, but only around two-thirds, (65%) of international aircraft flying into the U.S. have been retrofitted.

Despite the concerns of significant flight disruption due to the slow rollout of upgraded altimeters, the DOT has not suggested that the July 1 deadline will be extended.

Photo: Courtesy of Chris Leipelt / Unsplash

“We continue to see a significant number of aircraft still awaiting retrofit, including many operated by foreign air carriers,” said Transportation Secretary Pete Buttigieg in a letter to Airlines for America (A4A). “This means on bad-weather, low-visibility days in particular, there could be increased delays and cancellations.”

Buttigieg told airlines that have yet to update their altimeter technology across their fleet to “act now to adjust your schedules proactively… Carriers should consider how many aircraft still need to be retrofitted when setting and adjusting schedules to avoid causing consumers to rely on an unrealistic published schedule to their detriment.”

It has been confirmed that Delta Air Lines still needs to upgrade its complete fleet. The spokesperson of the Atlanta-based airline stated on Thursday that it still needs to retrofit approximately 190 of its narrowbody aircraft, which includes all of its Airbus A220s, the majority of A319s and A320s, and a few A321s.

Photo: Delta, Airbus A220-100. Courtesy of Trac Vu / Unsplash

“Many Delta teams have been working to insulate any additional delays from our customers and people through strategic aircraft routing,” said a spokesperson for Delta. “While we expect minimal operational impact, we continue to work with our supplier to see that every Delta aircraft is equipped with updated radio altimeters.”