June 3 (Reuters) - Major airlines want the Federal

Aviation Administration to delay a requirement set to take

effect in August requiring 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 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.

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

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

them resistant to forcible intrusion and unauthorized entry.