By David Shepardson
WASHINGTON (Reuters) -U.S. Transportation Secretary Pete Buttigieg warned Friday of potential delays starting July 1 for airplanes that have not yet had radio altimeters updated to address potential 5G C-Band interference and urged them to adjust schedules if needed.
While more than 80% of the domestic fleet serving U.S. airports has been updated, Buttigieg wrote in a letter to Airlines for America (A4A) "we continue to see a significant number of aircraft still awaiting retrofit, including many operated by foreign air carriers. This means on bad-weather, low-visibility days in particular, there could be increased delays and cancellations."
Concerns that 5G service could interfere with airplane altimeters, which give data on a plane's height above the ground and are crucial for bad-weather landing, led to brief disruptions at some U.S. airports last year as international carriers canceled some flights.
A4A, which represents major U.S. carriers, said carriers are working to update altimeters "but global supply chains continue to lag behind current demand.... A4A member carriers are confident in their ability to maintain the integrity of their schedules, despite the impending deadline."
International carriers have repeatedly sounded the alarm about the deadline.
Last year, Verizon (NYSE:VZ) and AT&T (NYSE:T) voluntarily agreed to delay some C-Band 5G usage until July as air carriers worked to retrofit airplane altimeters.
Buttigieg urged airlines who will be flying without the updated equipment "to act now to adjust your schedules proactively.... Carriers should consider how many of their 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."
Delta Air Lines (NYSE:DAL) said Friday its supplier told the airline it would not have enough radio altimeters for Delta’s entire fleet by July 1.
Approximately 190 Delta narrowbody aircraft are not yet equipped with updated radio altimeters including all A220s, most A319s and A320s, and some A321s. All Delta widebody aircraft will be equipped with updated radio altimeters prior to July 1, the airline said.
Reuters first reported in March that major U.S. wireless carriers agreed to some voluntary actions to address aviation safety concerns.
The agreement with AT&T, Verizon, T-Mobile US (NASDAQ:TMUS) and UScellular followed lengthy talks with the Federal Aviation Administration (FAA), allowing wireless carriers to increase power levels to get to full C-Band use on July 1.
Buttigieg added Friday "passengers must not bear the brunt of any airline’s inability to equip sufficient aircraft to be able to operate safely in the 5G C-band environment."