Boeing has begun certification flight testing for its long-delayed twin-engine 777-9 jet in order to be granted approval by US authorities, the aviation giant said Saturday.

“We began certification flight testing with US Federal Aviation Administration (FAA) personnel on board the aircraft,” the company said in a statement.

“The certification flight testing will continue validating the airplane’s safety, reliability and performance.”

Reached by AFP, the FAA declined to comment except to say that the certification process usually takes several months.

The testing comes as welcome news for Boeing, which has faced a series of setbacks amid concerns over the safety of its planes following a January in-flight incident that required an emergency landing.

The company says it has received over 530 orders for the entire 777-X family, which includes the 777-9. That fuel-efficient craft seats 426 passengers in a typical two-class configuration, with a range of over 13,500 kilometers (8,400 miles).

Boeing faced renewed scrutiny of its 737 MAX this year after a fuselage door plug blew out during an Alaska Airlines flight in January.

Earlier this week, Boeing said it had reached a deal with the US Justice Department over two fatal 737 MAX crashes, in 2018 and 2019 — with court documents indicating that the aviation giant would plead guilty to fraud.

Prosecutors had concluded that Boeing flouted an earlier settlement addressing the disasters, in which 346 people were killed in Ethiopia and Indonesia.

The high-profile agreement follows a Justice Department finding in May that Boeing failed to improve its compliance and ethics program, in breach of a 2021 deferred prosecution agreement reached in the wake of the MAX crashes.

In more bad news for the company, the aviation regulator announced earlier this week that over 2,600 737 jets would need inspections, amid concerns that passenger oxygen masks could fail in emergencies.