June 3 (Reuters) -

Major U.S. airlines want the Federal Aviation Administration

to delay by two years the requirement set to take effect in

August that new passenger airplanes have a secondary barrier to

the flight deck to prevent intrusions, the agency said on

Tuesday.

Airlines for America, the trade group representing American

Airlines ( AAL ), United Airlines, Delta Air Lines ( DAL )

and other major carriers, said in a petition that the

FAA should delay the requirement finalized in 2023 because the

agency has not yet approved a secondary cockpit barrier and no

manuals, procedures or training programs have been authorized.

The FAA said it was opening the airlines' request for public

comment through June 23.

After the hijacking of four U.S. airplanes on September 11,

2001, the FAA adopted standards for flight deck security to make

them resistant to forcible intrusion and unauthorized entry.

The airlines' petition said they expect the FAA to certify

the barriers in June or July. The FAA did not immediately

comment.

The rule requires aircraft manufacturers to install a second

physical barrier on planes used in commercial passenger service

in the United States. The FAA said in 2023 the additional

barrier will protect flight decks from intrusion when the flight

deck door is open.

Air Line Pilots Association President Jason Ambrosi

criticized the industry request.

"We urge the FAA to reject this latest stalling tactic

and implement, without delay, the secondary barrier requirement

as Congress mandated," he said.

Unions in 2023 urged that the rule take effect one year

after publication, while Boeing ( BA ), Airbus and

Airlines for America had called for three years.

The FAA was supposed to have adopted rules by 2019 under

a 2018 federal law, but the agency has said it was required to

follow procedural rules before it could impose new regulations.

The FAA is not requiring existing airplanes to be

retrofitted.

The FAA in 2007 set rules to address flight deck

security when the cockpit door was opened, including requiring

the door be locked when the airplane is in operation, unless

necessary to open it to permit access by authorized persons.