By David Shepardson

WASHINGTON (Reuters) -Major U.S. air carriers warned on Wednesday that plans by AT&T (NYSE:) and Verizon Communications (NYSE:) Using spectrum to support 5G wireless services may be disruptive for air travel. It could also result in $1.6 billion per year in delays.

Airlines for America (A4A), a trade group representing airlines, said that, in 2019, if an FAA directive was implemented to deal with interference from wireless transmissions, “approximately 325,000 passengers would be affected, as well as 5,400 cargo flight delays, diversions or cancellations.”

Wireless carriers can begin to use the spectrum within three weeks.

FAA released new guidelines last week regarding airworthiness, warning of interference from 5G mobile spectrum that could lead to flight divertsions.

FAA and the aviation industry have expressed concern about interference from 5G to sensitive electronics such as radio altimeters.

In November, AT&T and Verizon agreed to delay the commercial launch of C-band wireless service until Jan. 5 after the FAA raised concerns. To limit interference they took precautionary measures over six months.

According to aviation industry representatives, they are not sufficient to deal with safety issues in the air.

A&T and Verizon did not immediately comment.

A4A claimed that the FAA directive would “materially disrupt airline operations”, and cargo operators added that they believed the directive could have cost them $400 millions annually.

According to the group, travel delays can have an annual cost of $1.59 trillion to passengers.

It has not been shown that wireless carriers would be interested in additional delays to the spectrum, and it was purchased by an industry worth more than $80B.

Jessica Rosenworcel (FCC Chairwoman), did not comment immediately on the analysis of the airlines but stated that she believed the problems could be solved and the spectrum can safely be used.

A4a reported that airlines are dependent on airline customers to transport perishable, time-sensitive products like pharmaceuticals, vaccines or organs. The economy will be severely disrupted and damaged if 5G telecom companies fail to take serious steps to mitigate interference.

FAA Directives require that aircraft and helicopter pilots revise their flight manuals in order to ban certain operations that require radio altimeter data while using 5G CBand wireless broadband signals.

The FAA is still in talks with industry representatives, the FCC and the White House about any restrictions.