WASHINGTON (Reuters) -U.S. aviation regulators have issued an updated directive regarding a cracking issue with all of Boeing's 777 model airplanes, according to a notice posted online on Tuesday.

The Federal Aviation Administration's superseding airworthiness directive "was prompted by a report of a crack found in a front spar lower chord," it said in the Federal Register notice. Errors in the earlier directive also "introduced a new unsafe condition related to the application of certain fastener cap seals," it said.

Although Boeing submitted an initial report of errors in late 2022, the company did not produce "detailed and complete documentation of these errors was not received until late July 2023" due to the length and complexity of the requirements bulletin, the FAA said in the notice.

Although Boeing intends to revise the bulletin, the FAA issued the new directive as "this work will take longer to accomplish than the risk to public safety allows," the agency said.

A Boeing spokesperson said it fully supported the FAA's rule, “which is consistent with guidance we have shared with operators previously.”

The FAA did not immediately provide comment.

(Reporting by Susan Heavey, David Shepardson and Valerie Insinna, editing by Ed Osmond)