(Adds details from memo, FAA comment, reaction from ATT and Verizon)
By David Shepardson
WASHINGTON, May 24 (Reuters) - The Federal Aviation Administration (FAA) wants airlines to complete retrofits of some airplane radio altimeters that could face interference from C-Band 5G wireless service by the end of 2022, according to a memo seen by Reuters.
The FAA memo said following a May 19 meeting of airlines, manufacturers and wireless carriers that "a collective goal was set to complete" retrofits on some Embraer and Airbus planes by the end of the year. Another meeting is set for June 3.
The memo sets out a series of dates for actions by the aviation industry, including by June 1 asking airlines to "commit to purchase filters and installation kits." The FAA plans to develop a "tool to track and report progress in real time" by May 31, the memo says.
Radio altimeters give data on a plane's height above the ground and are crucial for bad-weather landings. AT&T and Verizon voluntarily agreed in January to delay through July 5 switching on some wireless towers and depowering others near airports just hours before the planned Jan. 19 deployment, averting what airlines had warned would cause a potentially "catastrophic" aviation safety crisis.
An airline trade group declined comment.
The FAA and altimeter manufacturers divided the U.S. commercial passenger airline fleet into four groups based on their tolerance to interference. Group 1 has the poorest performing altimeters and primarily consists of Embraer regional jets, while Group 2 is largely Airbus A320s, officials said.
The FAA wants 1,760 planes in Groups "1 and 2" to be retrofitted this year. None have been completed yet.
The memo also says retrofits should be completed for 4,800 Group 3 planes in 2023.
A separate May 19 FAA presentation warns more than 100 U.S. airports could eventually be off-limits without retrofits to Embraer planes in Group 1.
The memo says Airbus will need to complete service bulletins by July 21. Airbus did not immediately comment.
AT&T said in a statement it has made no additional commitments beyond July 5, but is "in discussions with the FAA and aviation on a phased deployment approach that will provide the aviation industry with some additional time to complete equipment updates without stalling our C-Band deployment."
Verizon said it is "encouraged by the work that’s been accomplished so far, including the robust deployment of 5G related equipment in and around airports. As this work continues, we’re confident that this effort will be resolved in a timely manner."
The FAA has shrunk zones around airports where Verizon and AT&T cannot fully use towers and is working to implement a refined zone that would allow more towers to be fully used. The number of towers that Verizon has been unable to use has been cut by more than 50% since January.
The FAA said Tuesday "we continue to make progress with the aviation and wireless industries so that 5G and aviation can continue to safely coexist." (Reporting by David Shepardson; Editing by Bernard Orr)